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PleasureCraft Engine Group 5.0L Diagnostic Manual

Mefi 4 / 4b series
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MEFI 4 / 4B
DIAGNOSTIC
MANUAL
5.0/5.7/6.0/8.1L
L510005P
11/05

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Summary of Contents for PleasureCraft Engine Group 5.0L

  • Page 1 MEFI 4 / 4B DIAGNOSTIC MANUAL 5.0/5.7/6.0/8.1L L510005P 11/05...
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  • Page 3 Marine Electronic Fuel Injection (MEFI 4 / 4B) Contents Section 1 - General Information ........................Page 1-1 Section 2 - ECM and Sensors .......................... Page 2-1 Section 3A - Fuel Metering System (5.0/5.7L) ....................Page 3A-1 Section 3B - Fuel Metering System (6.0L) .....................Page 3B-1 Section 3C - Fuel Metering System (8.1L) ....................
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  • Page 5: Table Of Contents

    5.0/5.7/6.0L/8.1L General Information 1 - 1 Marine Electronic Fuel Injection (MEFI) Section 1 General Information Contents General Description ..........Page 2 Clearing Diagnostic Trouble Codes (Scan) ..Page 5 Visual/Physical Inspection ....... Page 2 Non-Scan Diagnosis of Driveability Concerns Basic Knowledge and Tools Required ..... Page 2 (No DTCs Set) ..........Page 5 Electrostatic Discharge Damage .....

  • Page 6: General Description

    1 - 2 General Information 5.0/5.7/6.0/8.1L near a highly charged object and momentarily touches General Description ground. Charges of the same polarity are drained off, leaving the person highly charged with the opposite Visual and Physical Inspection polarity. Static charges of either type can cause damage. Therefore, it is important to use care when handling and Important: This visual and physical inspection is testing electronic components.

  • Page 7: Intermittent Malfunction Indicator Lamp (Mil)

    5.0/5.7/6.0L/8.1L General Information 1 - 3 Intermittent Malfunction Indicator Lamp (MIL) times. At the end of the DTC’s, the ECM will simply go back and start over with fl ashing DTC 12. In the case of an “intermittent” problem, the Malfunction Indicator Lamp (MIL) will light for 10 seconds, and then Service Mode go out.

  • Page 8: Scan Tool Use With Intermittents

    1 - 4 General Information 5.0/5.7/6.0/8.1L Scan Tool Use With Intermittents 5 VOLTS The scan tool provides the ability to perform a “wiggle test” on wiring harnesses or components with the engine not XXXXXXXXXXXXXXX DEFAULTXXXXXXXXXXX running, while observing the scan tool display. 4.6V The scan tool can be plugged in and observed while driving the boat under the condition when the MIL turns...

  • Page 9: Clearing Diagnostic Trouble Codes (Scan)

    5.0/5.7/6.0L/8.1L General Information 1 - 5 Clearing Diagnostic Trouble Codes (Scan) 1. Install scan tool. LOW TEMP - 5 VOLTS 2. Start engine. XXXXXXXXXXXXXXX DEFAULTXXXXXXXXXXX 3. Select “clear DTC’s” function. 4. Clear DTC’s. ------50 -4.2V OUT OF RANGE SENSOR 5. Turn ignition “OFF” for at least 20 seconds. 6.

  • Page 10: Service Precautions

    1 - 6 General Information 5.0/5.7/6.0/8.1L 9. When steam cleaning engines, do not direct the nozzle Service Precautions at any ECM system components. If this happens, The following requirements must be observed when corrosion of the terminals or damage of components working on MEFI equipped engines.

  • Page 11: Special Tools (1 Of 3)

    5.0/5.7/6.0L/8.1L General Information 1 - 7 Special Tools (1 of 3) VOLTMETER - Voltage position measures magnitude of voltage when connected in parallel to an existing circuit. A digital voltmeter with a 10 megohm input impedance TRUE RMS MULTIMETER is used because this type of meter will not load down MIN AVG AC DC AUTO 100 RECORD MAX...

  • Page 12: Special Tools (2 Of 3)

    1 - 8 General Information 5.0/5.7/6.0/8.1L Special Tools (2 of 3) METRI-PACK TERMINAL REMOVER Used for removing 150 series Metri-Pack “pull-to-seat” terminals from connectors. Refer to wiring harness service in MEFI General Information Section for removal procedure. J 35689 WEATHER PACK TERMINAL REMOVER Used for removing terminals from Weather Pack connectors.

  • Page 13: Special Tools (3 Of 3)

    5.0/5.7/6.0L/8.1L General Information 1 - 9 Special Tools (3 of 3) HARNESS TEST ADAPTER KIT Used to make electrical test connections in current Weather Pack, Metri-Pack and Micro-Pack style terminals. J 35616 20’ DIAGNOSTIC CONNECTOR EXTENSION CABLE Extension cable to go between the scan tool and the DLC on the engine harness.

  • Page 14: Abbreviations

    1 - 10 General Information 5.0/5.7/6.0/8.1L ABBREVIATIONS KNOCK SENSOR SYSTEM BARO BAROMETRIC PRESSURE KILOVOLTS BATTERY, BATTERY POSITIVE TERMINAL, BATTERY OR SYSTEM MANIFOLD ABSOLUTE PRESSURE VOLTAGE MEFI MARINE ELECTRONIC FUEL BATTERY POSITIVE INJECTION CRANKSHAFT POSITION SENSOR MULTIPORT FUEL INJECTION CIRCUIT MALFUNCTION INDICATOR LAMP CAMSHAFT POSITION SENSOR MSEC MILLSECOND...

  • Page 15: Diagnosis

    5.0/5.7/6.0L/8.1L General Information 1 - 11 Diagnosis • Tendency for connectors to come apart due to vibration and/or temperature cycling. The diagnostic tables and functional checks in this manual • Terminals not fully seated in the connector body. are designed to locate a faulty circuit or component through •...

  • Page 16: Wiring Connector Service

    1 - 12 General Information 5.0/5.7/6.0/8.1L Wiring Connector Service Metri-Pack Series 150 Terminals Figure 1-6 Most connectors in the engine compartment are protected against moisture and dirt which could create oxidation Some ECM harness connectors contain terminals called and deposits on the terminals. This protection is important Metri-Pack (Figure 1-6).

  • Page 17: Weather-Pack Connectors

    5.0/5.7/6.0L/8.1L General Information 1 - 13 Weather-Pack Connectors MALE FEMALE CONNECTOR CONNECTOR Figure 1-7 BODY BODY Figure 1-7 shows a Weather-Pack connector and the tool (J 28742 or equivalent) required to service it. This tool is used to remove the pin and sleeve terminals. If terminal removal is attempted without using the special tool required, there is a good chance that the terminal 1.

  • Page 18: Micro-Pack 100/W Series Connectors

    1 - 14 General Information 5.0/5.7/6.0/8.1L Micro-Pack 100/W Series Connectors Important • Figure 1-8 To ensure proper engine operation after repair of connector assembly, wires must be in proper connector The harness connectors used with the ECM “J1” and “J2” location.
  • Page 19 5.0/5.7/6.0L/8.1L General Information 1 - 15 TAB C TAB B TAB B TAB C FIGURE A - EXPLODED VIEW OF CONNECTOR ASSEMBLY 1 STRAIN RELIEF 3 CONNECTOR 2 SEAL 4 INDEX COVER TAB A TAB A TAB A TAB B TAB B 3 4 5 6 7 8 9 10111213141516 1920212223242526272829303132...
  • Page 20 1 - 16 General Information 5.0/5.7/6.0/8.1L This page left intentionally blank MEFI 4 - PCM...
  • Page 21 5.0/5.7/6.0L/8.1L ECM and Sensors 2 - 1 Marine Electronic Fuel Injection (MEFI) Section 2 Engine Control Module (ECM) and Sensors This section will describe the function of the Engine Control Module (ECM) and the sensors. The section explains how voltages reflect the inputs and outputs of the ECM. The sensors are described how they operate and how to replace them.

  • Page 22: General Description

    2 - 2 ECM and Sensors 5.0/5.7/6.0/8.1L General Description Three-Wire Sensors Figure 2-1 shows a schematic representation of a 3-wire The Marine Electronic Fuel Injection (MEFI) system is sensor. All 3-wire sensors have a reference voltage, a equipped with a computer that provides the operator with ground and a variable “wiper.”...

  • Page 23: Digital Signals

    5.0/5.7/6.0L/8.1L ECM and Sensors 2 - 3 Digital Signals Switch Types Switched inputs (also known as discretes) to the ECM can Digital signals are also variable, but not continuously. They cause one bit to change, resulting in information being can only be represented by distinct voltages within a range. communicated to the ECM.

  • Page 24: Engine Control Module (Ecm)

    2 - 4 ECM and Sensors 5.0/5.7/6.0/8.1L Engine Control Module (ECM) The ECM controls output circuits such as the injectors, IAC, relays, etc. by controlling the ground or power feed The Engine Control Module (ECM), located on the engine, circuit. is the control center of the fuel injection system.

  • Page 25: Speed Density System

    5.0/5.7/6.0L/8.1L ECM and Sensors 2 - 5 Speed Density System ECM Inputs and Sensor Descriptions The Marine Electronic Fuel Injection (MEFI) system is a Figure 2-5 lists the data sensors, switches, and other inputs speed and air density system. The system is based on used by the ECM to control its various systems.

  • Page 26: Mefi Inputs And Outputs

    2 - 6 ECM and Sensors 5.0/5.7/6.0/8.1L MEFI INPUTS AND OUTPUTS (TYPICAL) INPUTS OUTPUTS BATTERY 12V FUEL INJECTORS IGNITION 12V MULTIPLE IGNITION CONTROLS (IC) CRANKSHAFT POSITION SENSOR (RPM) FUEL PUMP RELAY CAMSHAFT POSITION IDLE AIR CONTROL (IAC) SENSOR THROTTLE POSITION OPERATOR INFORMATION (TP) SENSOR LAMPS/BUZZERS...

  • Page 27: Engine Coolant Temperature (Ect) Sensor

    5.0/5.7/6.0L/8.1L ECM and Sensors 2 - 7 Engine Coolant Temperature (ECT) Sensor The ECM supplies a 5 volt reference voltage to the MAP sensor. As the manifold pressure changes, the electrical The engine coolant temperature (ECT) sensor is a resistance of the MAP sensor also changes. By monitoring thermistor (a resistor which changes value based on the sensor output voltage, the ECM knows the manifold temperature) mounted in the engine coolant stream.

  • Page 28: Throttle Position (Tp) Sensor

    2 - 8 ECM and Sensors 5.0/5.7/6.0/8.1L Throttle Position (TP) Sensor Intake Air Temperature (IAT) Sensor (5.0/5.7L) The Throttle Position (TP) sensor is a potentiometer The Intake Air Temperature (IAT) sensor is a thermistor connected to the throttle shaft on the throttle body. which changes value based on the temperature of air By monitoring the voltage on the signal line, the ECM entering the engine (Figure 2-12).

  • Page 29: Knock Sensor

    5.0/5.7/6.0L/8.1L ECM and Sensors 2 - 9 Abnormal Knock Sensor Signal Knock Sensor (KS) System Description Purpose: To control spark knock (detonation), a knock sensor (KS) system is used. This system is designed to retard spark timing when excessive spark knock is detected in the engine.

  • Page 30: Diagnosis

    2 - 10 ECM and Sensors 5.0/5.7/6.0/8.1L On-Board Service Diagnosis Engine Control Module (ECM) Replacement Engine Control Module (ECM) Notice: When replacing the ECM, the ignition must be To read and clear diagnostic trouble codes, use a scan tool “OFF” and disconnect the battery before disconnecting or or Diagnostic Trouble Code (DTC) tool.

  • Page 31: System Relay

    5.0/5.7/6.0L/8.1L ECM and Sensors 2 - 11 System Relay Replacement Removal Procedure 1. Turn the ignition OFF. 2. Remove the retainer. 3. Disconnect the system relay electrical connector. 4. Remove the system relay. Important: The system relay is an electrical component. Do Not soak in any liquid or solvent as damage may result.

  • Page 32: Engine Coolant Temperature (Ect) Sensor

    2 - 12 ECM and Sensors 5.0/5.7/6.0/8.1L Engine Coolant Temperature (ECT) Sensor Replacement Notice: Care must be taken when handling the ECT sensor. Damage to the sensor will affect proper operation of the MEFI system. Remove or Disconnect 1. Turn OFF the ignition. 2.

  • Page 33: Manifold Absolute Pressure (Map)/Intake Air

    5.0/5.7/6.0L/8.1L ECM and Sensors 2 - 13 Manifold Absolute Pressure (MAP) / Intake Air Temperature (IAT) Sensor Replacement (5.0/5.7L) Removal Procedure 1. Remove the MAP sensor retaining stud. 2. Remove the MAP sensor from the intake manifold. 3. Inspect the MAP sensor seal for wear or damage and replace as necessary.

  • Page 34: Manifold Absolute Pressure (Map) Sensor (6.0/8.1L)

    2 - 14 ECM and Sensors 5.0/5.7/6.0/8.1L Manifold Absolute Pressure (MAP) Sensor Replacement (6.0/8.1L) Removal Procedure 1. Disconnect the manifold absolute pressure (MAP) sensor electrical connector (1). 684798 2. Remove the MAP sensor retaining bolt and washer (1). 3. Remove the MAP sensor (3) from the intake manifold (2).
  • Page 35 5.0/5.7/6.0L/8.1L ECM and Sensors 2 - 15 3. Connect the MAP sensor electrical connector (1). 684798 MEFI 4 - PCM...

  • Page 36: Throttle Position (Tp) Sensor

    2 - 16 ECM and Sensors 5.0/5.7/6.0/8.1L Throttle Position (TP) Sensor Remove or Disconnect 1. Flame arrestor. 2. TP sensor electrical connector. 3. TP sensor attaching screws (1). 4. TP sensor (2). Important • The TP sensor is an electrical component. Do Not soak in any liquid cleaner or solvent, as damage may result.

  • Page 37: Idle Air Control (Iac) Valve

    5.0/5.7/6.0L/8.1L ECM and Sensors 2 - 17 Idle Air Control (IAC) Valve Remove or Disconnect 1. Flame arrestor. 2. IAC electrical connector. 3. IAC valve attaching screws (1). 4. IAC valve (2). Notice: On IAC valves that have been in service, Do Not push or pull on the IAC valve pintle.

  • Page 38: Knock Sensor (Ks) (5.0/5.7L)

    2 - 18 ECM and Sensors 5.0/5.7/6.0/8.1L Knock Sensor (KS) (5.0/5.7L) Remove or Disconnect 1. Negative battery cable. 2. Knock sensor electrical connector. 3. Knock sensor from engine block. 1 KNOCK SENSOR 2 ENGINE BLOCK RS 22182 Install or Connect Important •...
  • Page 39 5.0/5.7/6.0L/8.1L ECM and Sensors 2 - 19 4. Remove the knock sensors. Install or Connect Important • If installing a new knock sensor, be sure to replace with an identical part number. • When installing knock sensor, be sure to install in the same location removed from.

  • Page 40: Torque Specifi Cations

    2 - 20 ECM and Sensors 5.0/5.7/6.0/8.1L Torque Specifi cations Fastener Tightening Specifi cations (5.0/5.7L) Application N•m Lb Ft Lb In ECM Mounting Screws 10-14 88-124 ECT Sensor MAP/IAT Sensor Attaching Stud 44-62 TP Sensor Attaching Screws IAC Valve Attaching Screws Knock Sensor 15-22 11-16...
  • Page 41 5.0/5.7L Fuel Metering System 3A - 1 Marine Electronic Fuel Injection (MEFI) Section 3A Fuel Metering System - 5.0/5.7L This section describes how the fuel metering system operates, and provides a description of components used on the Marine Electronic Fuel Injection equipped engines. The fuel metering system information described in this section is limited to the 5.0/5.7L.

  • Page 42: General Description

    3A - 2 Fuel Metering System 5.0/5.7L General Description Power Reduction Mode Power reduction mode is a function of the ECM that Purpose reduces engine power under certain conditions. Power reduction will The function of the fuel metering system is to deliver the disable one fuel injector driver when the engine speed goes correct amount of fuel to the engine under all operating above 2500 rpm, and enable the fuel injector driver when the...
  • Page 43 5.0/5.7L Fuel Metering System 3A - 3 PRESSURE REGULATOR Fuel Control Cell Fuel System FUEL RAIL ASSEMBLY LOW- FUEL PRESSURE FILTER FUEL FUEL PUMP ENGINE CONTROL CELL FUEL TANK Figure 3-1 - Fuel Metering System (Typical) Figure 3-2 - Typical Fuel Control Cell (FCC) Figure 3-3 - Low Pressure Fuel Pump MEFI 4 - PCM...

  • Page 44: Fuel Pump Electrical Circuit

    3A - 4 Fuel Metering System 5.0/5.7L Fuel Pump Electrical Circuit Fuel Injectors The fuel injector assembly is a solenoid-operated device, When the ignition switch is turned “ON,” the ECM turns controlled by the ECM, that meters pressurized fuel to a the fuel pump relay “ON”...

  • Page 45: Pressure Regulator Assembly

    5.0/5.7L Fuel Metering System 3A - 5 Pressure Regulator Assembly Throttle Body Assembly The pressure regulator is a diaphragm-operated relief The throttle body assembly is attached to the intake valve with fuel pump pressure on one side, and regulator manifold air plenum, and is used to control air fl ow into the spring pressure and intake manifold vacuum on the other engine, thereby controlling engine output (Figure 3-6).

  • Page 46: Idle Air Control (Iac) Valve

    3A - 6 Fuel Metering System 5.0/5.7L Idle Air Control (IAC) Valve • “Controlled” idle speed is programmed into the ECM, The purpose of the IAC valve assembly (Figures 3-7 and which determines the correct IAC valve pintle position to maintain the desired idle speed for all engine 3-8) is to control engine idle speed, while preventing stalls due to changes in engine load.

  • Page 47: Fuel Control On-Board Service

    5.0/5.7L Fuel Metering System 3A - 7 Fuel Control On-Board Service 2. Loosen fuel filler cap to relieve any tank vapor pressure. The following is general information required when working 3. Connect fuel pressure gauge J 34730-1 to fuel pressure on the fuel system: connector assembly.

  • Page 48: Throttle Body Assembly

    3A - 8 Fuel Metering System 5.0/5.7L Throttle Body Assembly The throttle body assembly repair procedures cover component replacement with the unit on the vessel. However, throttle body replacement requires that the complete unit be removed from the engine. Clean Important •...

  • Page 49: Quick Connect Fitting(S) Service

    5.0/5.7L Fuel Metering System 3A - 9 Quick Connect Fitting(s) Service Tools Required J 37088-A Tool Set, Fuel Line Quick-Connect Separator J 44581 Fuel Line Quick Connect Separator Removal Procedure 1. Relieve the fuel system pressure before servicing any fuel system connection. Refer to Fuel Pressure Relief Procedure.
  • Page 50 3A - 10 Fuel Metering System 5.0/5.7L Installation Procedure 1. Apply a few drops of clean engine oil to the male pipe end. 12784 2. Push both sides of the fi tting together in order to snap the retaining tabs into place. 12786 3.

  • Page 51: Fuel Rail Assembly

    5.0/5.7L Fuel Metering System 3A - 11 Clean and Inspect Fuel Rail Assembly Notice: If it is necessary to remove rust or burrs from The fuel rails should be removed as an assembly with the fuel rail pipes, use emery cloth in a radial motion with the injectors attached.
  • Page 52 3A - 12 Fuel Metering System 5.0/5.7L Fuel Rail Removal and Installation Fuel Rail Assembly Legend Fuel Rail Attaching Stud Fuel Injector Retaining Clip Fuel Pressure Connection Cap Fuel Pressure Regulator Fuel Rail Assembly Fuel Pressure Regulator Retaining Clip Fuel Injector O-Ring Fuel Pressure Regulator Vacuum LIne Fuel Injector Assembly MEFI 4 - PCM...

  • Page 53: Fuel Injectors

    5.0/5.7L Fuel Metering System 3A - 13 Fuel Injectors Notice: Use care in removing injectors to prevent damage to the injector electrical connector pins or the injector spray tips. The fuel injector is serviced as a complete assembly only. Since it is an electrical component, Do Not immerse it in any cleaner.

  • Page 54: Fuel Pressure Regulator Assembly

    3A - 14 Fuel Metering System 5.0/5.7L Install or Connect Fuel Pressure Regulator Assembly 1. Lubricate new fuel pressure regulator O-ring with clean Important engine oil and install on regulator. • The fuel pressure regulator is serviced as a complete 2.

  • Page 55: Fuel Control Cell (Fcc)

    5.0/5.7L Fuel Metering System 3A - 15 Fuel Control Cell (FCC) Replacement - Screw On Bowl and Clamp On Bowl Important • Fuel pressure must be relieved before servicing the fuel pump. • Refer to “Fuel Pressure Relief Procedure.” Remove or Disconnect 1.
  • Page 56 3A - 16 Fuel Metering System 5.0/5.7L Fuel Control Cell (FCC) - Screw On Bowl - Fuel Control Cell (FCC) - Screw On Bowl - Drain Water (With Engine OFF) Element Replacement (With Engine OFF) 1. Disconnect the two-wire electrical harness. 1.
  • Page 57 5.0/5.7L Fuel Metering System 3A - 17 Fuel Control Cell (FCC) - Clamp On Bowl - Fuel Control Cell (FCC) - Clamp On Bowl - Drain Water (With Engine OFF) Element Replacement (With Engine OFF) 1. Disconnect the two-wire electrical harness. 1.

  • Page 58: Low-Pressure Fuel Pump

    3A - 18 Fuel Metering System 5.0/5.7L Low-Pressure Fuel Pump Replacement Important • Fuel pressure must be relieved before servicing the fuel pump. • Refer to “Fuel Pressure Relief Procedure.” Remove or Disconnect 1. Negative battery cable. 2. Fuel pump electrical connector. 3.
  • Page 59 5.0/5.7L Fuel Metering System 3A - 19 Torque Specifi cations Fastener Tightening Specifi cations Application N•m Lb Ft Lb In Throttle Body Attaching Screws IAC Valve Attaching Screws Fuel Pressure Connector Fuel Rail Attaching Screws MEFI 4 - PCM...
  • Page 60 3A - 20 Fuel Metering System 5.0/5.7L This page left intentionally blank MEFI 4 - PCM...
  • Page 61 6.0L Fuel Metering System 3B - 1 Marine Electronic Fuel Injection (MEFI) Section 3B Fuel Metering System - 6.0L This section describes how the fuel metering system operates, and provides a description of components used on the Marine Electronic Fuel Injection equipped engines. The fuel metering system information described in this section is limited to the 6.0L.

  • Page 62: General Description

    3B - 2 Fuel Metering System 6.0L engine power under certain conditions. Power reduction will General Description disable one fuel injector driver when the engine speed goes above 2500 rpm, and enable the fuel injector driver when Purpose the engine speed drops below 1200 rpm. Power reduction The function of the fuel metering system is to deliver the may be active for the following conditions: correct amount of fuel to the engine under all operating...
  • Page 63 6.0L Fuel Metering System 3B - 3 Fuel Control Cell Fuel System FUEL RAIL ASSEMBLY (Returnless Fuel Rail) LOW- PRESS. FUEL PRESSURE REG. FILTER FUEL PUMP ENGINE FUEL CONTROL CELL FUEL TANK M4054P 2-12-04 Figure 3-1 - Fuel Metering System (Typical) Figure 3-2 - Fuel Control Cell (FCC) Figure 3-3 - Low Pressure Fuel Pump MEFI 4 - PCM...

  • Page 64: Fuel Pump Electrical Circuit

    3B - 4 Fuel Metering System 6.0L Fuel Injectors Fuel Pump Electrical Circuit The Multec 2 fuel injector assembly is a solenoid When the ignition switch is turned “ON,” the ECM turns operated device, controlled by the ECM, that meters the fuel pump relay “ON”...

  • Page 65: Pressure Regulator Assembly

    6.0L Fuel Metering System 3B - 5 Pressure Regulator Assembly Throttle Body Assembly The pressure regulator is a diaphragm-operated relief valve The throttle body assembly is attached to the intake with fuel pump pressure on one side, and regulator spring manifold air plenum, and is used to control air fl...

  • Page 66: Idle Air Control (Iac) Valve

    3B - 6 Fuel Metering System 6.0L Idle Air Control (IAC) Valve • “Controlled” idle speed is programmed into the ECM, The purpose of the IAC valve assembly (Figures 3-7 and which determines the correct IAC valve pintle position to maintain the desired idle speed for all engine 3-8) is to control engine idle speed, while preventing stalls due to changes in engine load.

  • Page 67: Fuel Control On-Board Service

    6.0L Fuel Metering System 3B - 7 Fuel Control On-Board Service 2. Loosen fuel filler cap to relieve any tank vapor pressure. The following is general information required when working 3. Connect fuel pressure gauge J 34730-1 to fuel pressure on the fuel system: connector assembly.

  • Page 68: Throttle Body Assembly

    3B - 8 Fuel Metering System 6.0L Throttle Body Assembly Replacement Remove or Disconnect 1. Disconnect the negative battery cable. 2. Remove the fl ame arrestor clamp and fl ame arrestor. 3. Disconnect the electrical connectors from the IAC valve and the TP sensor. 4.

  • Page 69: Quick Connect Fitting(S) Service

    6.0L Fuel Metering System 3B - 9 Quick Connect Fitting(s) Service Tools Required J 37088-A Tool Set, Fuel Line Quick-Connect Separator J 44581 Fuel Line Quick Connect Separator Remove or Disconnect 1. Relieve the fuel system pressure before servicing any fuel system connection. Refer to Fuel Pressure Relief Procedure.
  • Page 70 3B - 10 Fuel Metering System 6.0L 5. Pull the connection apart. 6. Use a clean shop towel in order to wipe off the male pipe end. 7. Inspect both ends of the fi tting for dirt and burrs. Clean or replace the components as required.
  • Page 71 6.0L Fuel Metering System 3B - 11 3. Once installed, pull on both sides of the fi tting in order to make sure the connection is secure. 12787 4. Install the retainer on to the quick-connect fi tting. 1238589 MEFI 4 - PCM...

  • Page 72: Fuel Rail Assembly

    3B - 12 Fuel Metering System 6.0L Fuel Rail Assembly Replacement Remove or Disconnect 1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure. 2. Remove the engine cover. 3. Before removal, clean the fuel rail assembly with a spray type engine cleaner, GM X-30A or equivalent, if necessary.
  • Page 73 6.0L Fuel Metering System 3B - 13 12. Remove the fuel rail attaching bolts. 13. Remove the fuel rail assembly. Notice: • Remove the fuel rail assembly carefully in order to prevent damage to the injector electrical connector terminals and the injector spray tips. Support the fuel rail after the fuel rail is removed in order to avoid damaging the fuel rail components.
  • Page 74 3B - 14 Fuel Metering System 6.0L 3. Install the fuel rail assembly to the intake manifold. 4. Apply a 5 mm (0.020 in) band of GM P/N 12345382 threadlock or equivalent to the threads of the fuel rail attaching bolts. 5.
  • Page 75 6.0L Fuel Metering System 3B - 15 Fuel Injector Replacement Remove or Disconnect Important: The engine oil may be contaminated with fuel if the fuel injectors are leaking. 1. Remove the fuel rail assembly. Refer to Fuel Rail Assembly Replacement. 2.
  • Page 76 3B - 16 Fuel Metering System 6.0L 1. Lubricate the new O-ring seals (2), (4) with clean engine oil. 2. Install the new injector O-ring seals on the injector. 3. Install a new retainer clip (1) on the injector. 351185 4.

  • Page 77: Fuel Control Cell (Fcc)

    6.0L Fuel Metering System 3B - 17 Fuel Control Cell (FCC) Replacement - Screw On Bowl and Clamp On Bowl Important • Fuel pressure must be relieved before servicing the fuel pump. • Refer to “Fuel Pressure Relief Procedure.” Remove or Disconnect 1.

  • Page 78: Fuel Pressure Regulator

    3B - 18 Fuel Metering System 6.0L Fuel Control Cell (FCC) - Screw On Bowl - Fuel Control Cell (FCC) - Screw On Bowl - Drain Water (With Engine OFF) Element Replacement (With Engine OFF) 1. Disconnect the two-wire electrical harness. 1.
  • Page 79 6.0L Fuel Metering System 3B - 19 Fuel Control Cell (FCC) - Clamp On Bowl - Fuel Control Cell (FCC) - Clamp On Bowl - Drain Water (With Engine OFF) Element Replacement (With Engine OFF) 1. Disconnect the two-wire electrical harness. 1.
  • Page 80 3B - 20 Fuel Metering System 6.0L Fuel Pressure Regulator Replacement Remove or Disconnect Important • Fuel pressure must be relieved before servicing the fuel pump. • Refer to “Fuel Pressure Relief Procedure.” 1. Remove the FCC bowl. Refer to Fuel Control Cell - Element Replacement steps 1-5.

  • Page 81: Fuel Pump Relay

    6.0L Fuel Metering System 3B - 21 Low-Pressure Fuel Pump Replacement Important • Fuel pressure must be relieved before servicing the fuel pump. • Refer to “Fuel Pressure Relief Procedure.” Remove or Disconnect 1. Negative battery cable. 2. Fuel pump electrical connector. 3.

  • Page 82: Torque Specifi Cations

    3B - 22 Fuel Metering System 6.0L Torque Specifi cations Fastener Tightening Specifi cations Application N•m Lb Ft Lb In Throttle Body Attaching Screws IAC Valve Attaching Screws Fuel Pressure Connector Fuel Rail Attaching Screws MEFI 4 - PCM...
  • Page 83 8.1L Fuel Metering System 3C - 1 Marine Electronic Fuel Injection (MEFI) Section 3C Fuel Metering System - 8.1L This section describes how the fuel metering system operates, and provides a description of components used on the Marine Electronic Fuel Injection equipped engines. The fuel metering system information described in this section is limited to the 8.1L.

  • Page 84: General Description

    3C - 2 Fuel Metering System 8.1L engine power under certain conditions. Power reduction will General Description disable one fuel injector driver when the engine speed goes above 2500 rpm, and enable the fuel injector driver when Purpose the engine speed drops below 1200 rpm. Power reduction The function of the fuel metering system is to deliver the may be active for the following conditions: correct amount of fuel to the engine under all operating...
  • Page 85 8.1L Fuel Metering System 3C - 3 PRESSURE REGULATOR Fuel Control Cell Fuel System FUEL RAIL ASSEMBLY LOW- FUEL PRESSURE FILTER FUEL FUEL PUMP ENGINE CONTROL CELL FUEL TANK Figure 3-1 - Fuel Metering System (Typical) Figure 3-2 - Fuel Control Cell (FCC) Figure 3-3 - Low Pressure Fuel Pump MEFI 4 - PCM...

  • Page 86: Fuel Pump Electrical Circuit

    3C - 4 Fuel Metering System 8.1L Fuel Injectors Fuel Pump Electrical Circuit The Multec 2 fuel injector assembly is a solenoid When the ignition switch is turned “ON,” the ECM turns operated device, controlled by the ECM, that meters the fuel pump relay “ON”...

  • Page 87: Pressure Regulator Assembly

    8.1L Fuel Metering System 3C - 5 Pressure Regulator Assembly Throttle Body Assembly The pressure regulator is a diaphragm-operated relief The throttle body assembly is attached to the intake valve with fuel pump pressure on one side, and regulator manifold air plenum, and is used to control air fl ow into the spring pressure and intake manifold vacuum on the other engine, thereby controlling engine output (Figure 3-6).

  • Page 88: Idle Air Control (Iac) Valve

    3C - 6 Fuel Metering System 8.1L Idle Air Control (IAC) Valve • “Controlled” idle speed is programmed into the ECM, The purpose of the IAC valve assembly (Figures 3-7 and which determines the correct IAC valve pintle position to maintain the desired idle speed for all engine 3-8) is to control engine idle speed, while preventing stalls due to changes in engine load.

  • Page 89: Fuel Control On-Board Service

    8.1L Fuel Metering System 3C - 7 Fuel Control On-Board Service 2. Loosen fuel filler cap to relieve any tank vapor pressure. The following is general information required when working 3. Connect fuel pressure gauge J 34730-1 to fuel pressure on the fuel system: connector assembly.

  • Page 90: Throttle Body Assembly

    3C - 8 Fuel Metering System 8.1L Throttle Body Assembly Replacement Remove or Disconnect 1. Disconnect the negative battery cable. 2. Remove the fl ame arrestor clamp and fl ame arrestor. 3. Disconnect the electrical connectors from the IAC valve and the TP sensor. 4.

  • Page 91: Quick Connect Fitting(S) Service

    8.1L Fuel Metering System 3C - 9 Quick Connect Fitting(s) Service Tools Required J 37088-A Tool Set, Fuel Line Quick-Connect Separator J 44581 Fuel Line Quick Connect Separator Remove or Disconnect 1. Relieve the fuel system pressure before servicing any fuel system connection. Refer to Fuel Pressure Relief Procedure.
  • Page 92 3C - 10 Fuel Metering System 8.1L Install or Connect 1. Apply a few drops of clean engine oil to the male pipe end. 12784 2. Push both sides of the fi tting together in order to snap the retaining tabs into place. 12786 3.

  • Page 93: Fuel Rail Assembly

    8.1L Fuel Metering System 3C - 11 Fuel Rail Assembly Replacement Remove or Disconnect 1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure. 2. Before removal, clean the fuel rail assembly with a spray type engine cleaner, GM X-30A or equivalent, if necessary.
  • Page 94 3C - 12 Fuel Metering System 8.1L 8. Push the tab (1) on the lower side of the injector connector in order to release the connector from the injector. 9. Repeat step 9 and step 10 for each injector connector. 372753 10.
  • Page 95 8.1L Fuel Metering System 3C - 13 12. Remove the fuel rail attaching bolts. 13. Remove the fuel rail assembly. 665443 14. Remove the injector lower O-ring seal (4) from the spray tip end of each injector (3). 15. Discard the O-ring seals. 351185 Install or Connect 1.
  • Page 96 3C - 14 Fuel Metering System 8.1L 3. Install the fuel rail assembly to the intake manifold. 4. Apply a 5 mm (0.020 in) band of GM P/N 12345382 threadlock or equivalent to the threads of the fuel rail attaching bolts. 5.
  • Page 97 8.1L Fuel Metering System 3C - 15 8. Connect the injector electrical connectors • Install each connector on the proper injector in order to ensure correct injector fi ring order. • Rotate the injectors as required in order to avoid stretching the wire harness.
  • Page 98 3C - 16 Fuel Metering System 8.1L Fuel Pressure Regulator Replacement Remove or Disconnect 1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure. 2. Disconnect the fuel pressure regulator vacuum line (1). 665447 3. Clean any dirt from the fuel pressure regulator retainer and the surrounding area.
  • Page 99 8.1L Fuel Metering System 3C - 17 8. Connect the fuel pressure regulator vacuum line. 9. Connect the negative battery cable. 10. Inspect for leaks. 10.1. Turn the ignition ON for 2 seconds. 10.2. Turn the ignition OFF for 10 seconds. 10.3.
  • Page 100 3C - 18 Fuel Metering System 8.1L 4. Discard the injector retainer clip (1). 5. Remove the injector O-ring seals (2), (4) from both ends of the injector. Discard the O-ring seals. 351185 Install or Connect Important: When ordering new fuel injectors, be sure to order the correct injector for the application being serviced.
  • Page 101 8.1L Fuel Metering System 3C - 19 4. Push the fuel injector (5) into the fuel rail injector socket with the electrical connector facing outwards. The retainer clip (4) locks on to a fl ange on the fuel rail injector socket. 5.

  • Page 102: Fuel Control Cell (Fcc)

    3C - 20 Fuel Metering System 8.1L Fuel Control Cell (FCC) Replacement - Screw On Bowl and Clamp On Bowl Important • Fuel pressure must be relieved before servicing the fuel pump. • Refer to “Fuel Pressure Relief Procedure.” Remove or Disconnect 1.
  • Page 103 8.1L Fuel Metering System 3C - 21 Fuel Control Cell (FCC) - Screw On Bowl - Fuel Control Cell (FCC) - Screw On Bowl - Drain Water (With Engine OFF) Element Replacement (With Engine OFF) 1. Disconnect the two-wire electrical harness. 1.
  • Page 104 3C - 22 Fuel Metering System 8.1L Fuel Control Cell (FCC) - Clamp On Bowl - Fuel Control Cell (FCC) - Clamp On Bowl - Drain Water (With Engine OFF) Element Replacement (With Engine OFF) 1. Disconnect the two-wire electrical harness. 1.

  • Page 105: Low-Pressure Fuel Pump

    8.1L Fuel Metering System 3C - 23 Low-Pressure Fuel Pump Replacement Important • Fuel pressure must be relieved before servicing the fuel pump. • Refer to “Fuel Pressure Relief Procedure.” Remove or Disconnect 1. Negative battery cable. 2. Fuel pump electrical connector. 3.
  • Page 106 3C - 24 Fuel Metering System 8.1L Torque Specifi cations Fastener Tightening Specifi cations Application N•m Lb Ft Lb In Throttle Body Attaching Screws IAC Valve Attaching Screws Fuel Pressure Connector Fuel Pressure Regulator Attaching Screw Fuel Pressure Regulator Outlet Line Nut 17.5 Fuel Rail Jumper Line Attaching Screws Fuel Rail Attaching Screws...
  • Page 107 Distributor Ignition (DI) This section will describe the Distributor Ignition (DI) System used on the 5.0L and the 5.7L engines. The DI system uses a single ignition coil and a mechanical distributor. The section explains the individual components of the Distributor Ignition System.

  • Page 108: Ignition System Specifi Cations

    4A - 2 Distributor Ignition 5.0/5.7L Ignition System Specifi cations Specifi cations Application Metric English Firing Order 1-8-4-3-6-5-7-2 Spark Plug Wire Resistance 10,000 ohms per foot 15 N . m Spark Plug Torque 11 lb ft Spark Plug Gap 1.52 mm .060 in Spark Plug Type R030010...

  • Page 109: Distributor Ignition (Di) System Description

    5.0/5.7L Distributor Ignition 4A - 3 Crankshaft Position (CKP) Sensor and Reluctor Distributor Ignition (DI) System Description Wheel Ignition System Overview The ignition system consists of the following components or circuits: • The 8 ignition secondary wires • The ignition coil •...

  • Page 110: Camshaft Position (Cmp) Sensor And Reluctor Wheel

    4A - 4 Distributor Ignition 5.0/5.7L Camshaft Position (CMP) Sensor and Reluctor Ignition Coil Wheel The camshaft position (CMP) sensor works in conjunction with a 1X reluctor wheel mounted inside the distributor housing. The CMP is used to determine the top dead center position of cylinder #1, and will synchronize with the 4X CKP sensor signal for quicker starting.

  • Page 111: Noteworthy Ignition Information

    5.0/5.7L Distributor Ignition 4A - 5 Noteworthy Ignition Information There are important considerations to point out when servicing the ignition system. The following noteworthy information will list some of these to help the technician in servicing the ignition system. • The ignition coils secondary voltage output capabilities are very high - more than 40,000 volts.

  • Page 112: Knock Sensor (Ks) System Description

    4A - 6 Distributor Ignition 5.0/5.7L Abnormal Knock Sensor Signal Knock Sensor (KS) System Description Purpose To control spark knock (detonation), a knock sensor (KS) system is used. This system is designed to retard spark timing when excessive spark knock is detected in the engine.

  • Page 113: Ignition Coil Replacement

    5.0/5.7L Distributor Ignition 4A - 7 Ignition Coil Replacement Removal Procedure 1. Disconnect the secondary coil wire at the ignition coil. Refer to Spark Plug Wire Replacement. 2. Disconnect the ignition coil harness connector. 3. Remove the ignition coil mounting bolts. 4.

  • Page 114: Spark Plug Wire Inspection

    4A - 8 Distributor Ignition 5.0/5.7L Spark Plug Wire Inspection Spark plug wire integrity is vital for proper engine operation. A thorough inspection will be necessary to accurately identify conditions that may affect engine operation. Inspect for the following conditions: 1.

  • Page 115: Spark Plug Replacement

    5.0/5.7L Distributor Ignition 4A - 9 Spark Plug Replacement Removal Procedure 1. Remove the spark plug wires. Refer to Spark Plug Wire Replacement. 2. Loosen each spark plug one or two turns. 3. Brush or air blast away any dirt from around the spark plugs.
  • Page 116 4A - 10 Distributor Ignition 5.0/5.7L – Inspect the spark plug boot for damage. – Inspect the spark plug recess area of the cylinder head for moisture, such as oil, coolant or water. A spark plug boot that is saturated causes arcing to ground.

  • Page 117: Spark Plug Visual Inspection

    5.0/5.7L Distributor Ignition 4A - 11 • Inspect for evidence of improper arcing. – Measure the gap between the center electrode (4) and the side electrode (3) terminals. An excessively wide electrode gap can prevent correct spark plug operation. – Inspect for the correct spark plug torque.
  • Page 118 4A - 12 Distributor Ignition 5.0/5.7L • Deposit Fouling - Oil, coolant or additives that include substances such as silicone, very white coating, reduces the spark intensity. Most powdery deposits will not effect spark intensity unless they form into a glazing over the electrode. Installation Procedure 1.

  • Page 119: Crankshaft Position (Ckp) Sensor Replacement

    5.0/5.7L Distributor Ignition 4A - 13 Crankshaft Position (CKP) Sensor Replacement Removal Procedure 1. Disconnect the crankshaft position (CKP) sensor harness connector at the CKP sensor. 2. Remove the CKP sensor retaining bolt. 3. Remove the CKP sensor. 11485 Important: Always install a NEW crankshaft position sensor O-ring during assembly.

  • Page 120: Camshaft Position (Cmp) Sensor Replacement

    4A - 14 Distributor Ignition 5.0/5.7L Camshaft Position (CMP) Sensor Replacement Removal Procedure 1. Disconnect the camshaft position (CMP) sensor harness connector from the CMP sensor (2). 2. Remove the distributor cap bolts (1). 3. Remove the distributor cap. M4089 4.

  • Page 121: Setting Cam Retard

    5.0/5.7L Distributor Ignition 4A - 15 6. Install the distributor cap. 7. Install the distributor cap bolts (1). Tighten Tighten the distributor cap bolts to 2.4 N . m (21 lb in). 8. Connect the camshaft position (CMP) sensor harness connector to the CMP sensor (2).

  • Page 122: Knock Sensor (Ks) Replacement

    4A - 16 Distributor Ignition 5.0/5.7L Knock Sensor (KS) Replacement Removal Procedure 1. Remove the wiring harness connector from the knock sensor (2). 2. Remove the knock sensor (2) from the engine block (1). 20272 Installation Procedure 1. Install the knock sensor (2) into the engine block (1). Tighten Tighten the knock sensor to 19 N .
  • Page 123 6.0/8.1L Electronic Ignition 4B - 1 Marine Electronic Fuel Injection (MEFI 4) Section 4B Electronic Ignition This section will describe the Electronic Ignition (EI) System used on the 6.0L and 8.1L engines. The EI system uses an individual ignition coil for each cylinder. The section explains the individual components of the Electronic Ignition System. Distributor Ignition System is explained in Section 4A.

  • Page 124: Ignition System Specifi Cations

    4B - 2 Electronic Ignition 6.0/8.1L Ignition System Specifi cations Application Metric English Firing Order 1-8-7-2-6-5-4-3 Spark Plug Wire Resistance 10,000 ohms per foot 15 N . m Spark Plug Torque 11 lb ft Spark Plug Gap 1.52 mm .060 in Spark Plug Type - 6.0L R030011 Spark Plug Type - 8.1L...

  • Page 125: Electronic Ignition (Ei) System Description

    6.0/8.1L Electronic Ignition 4B - 3 Crankshaft Position (CKP) Sensor and Reluctor Electronic Ignition (EI) System Description Wheel Ignition System Overview The ignition system consists of the following components or circuits: • The 8 ignition secondary wires • The 8 ignition coils •...

  • Page 126: Camshaft Position (Cmp) Sensor And Reluctor Wheel

    4B - 4 Electronic Ignition 6.0/8.1L Camshaft Position (CMP) Sensor and Reluctor Ignition Coils Wheel The camshaft position (CMP) sensor works in conjunction with a 1X reluctor wheel mounted at the rear of the camshaft. The CMP is used to determine the top dead center position of cylinder #1, and will synchronize with the 24X CKP sensor signal for quicker starting.

  • Page 127: Noteworthy Ignition Information

    6.0/8.1L Electronic Ignition 4B - 5 Noteworthy Ignition Information There are important considerations to point out when servicing the ignition system. The following noteworthy information will list some of these to help the technician in servicing the ignition system. • The ignition coils secondary voltage output capabilities are very high - more than 40,000 volts.

  • Page 128: Knock Sensor (Ks) System Description

    4B - 6 Electronic Ignition 6.0/8.1L Abnormal Knock Sensor Signal Knock Sensor (KS) System Description Purpose To control spark knock (detonation), a knock sensor (KS) system is used. This system is designed to retard spark timing when excessive spark knock is detected in the engine.

  • Page 129: Ignition Coil(S) Replacement

    6.0/8.1L Electronic Ignition 4B - 7 Ignition Coil(s) Replacement Removal Procedure 1. Disconnect the spark plug wires at the ignition coils. Refer to Spark Plug Wire Replacement. 2. Disconnect the ignition coil harness connector. 3. Remove the ignition coil mounting bolts. 4.

  • Page 130: Spark Plug Wire Inspection

    4B - 8 Electronic Ignition 6.0/8.1L Spark Plug Wire Inspection Spark plug wire integrity is vital for proper engine operation. A thorough inspection will be necessary to accurately identify conditions that may affect engine operation. Inspect for the following conditions: 1.

  • Page 131: Spark Plug Replacement

    6.0/8.1L Electronic Ignition 4B - 9 Spark Plug Replacement Removal Procedure 1. Remove the spark plug wires. Refer to Spark Plug Wire Replacement. 2. Loosen each spark plug one or two turns. 3. Brush or air blast away any dirt from around the spark plugs.
  • Page 132 4B - 10 Electronic Ignition 6.0/8.1L – Inspect the spark plug boot for damage. – Inspect the spark plug recess area of the cylinder head for moisture, such as oil, coolant or water. A spark plug boot that is saturated causes arcing to ground.

  • Page 133: Spark Plug Visual Inspection

    6.0/8.1L Electronic Ignition 4B - 11 • Inspect for evidence of improper arcing. – Measure the gap between the center electrode (4) and the side electrode (3) terminals. An excessively wide electrode gap can prevent correct spark plug operation. – Inspect for the correct spark plug torque.
  • Page 134 4B - 12 Electronic Ignition 6.0/8.1L • Deposit Fouling - Oil, coolant or additives that include substances such as silicone, very white coating, reduces the spark intensity. Most powdery deposits will not effect spark intensity unless they form into a glazing over the electrode. Installation Procedure 1.

  • Page 135: Crankshaft Position (Ckp) Sensor Replacement - 6.0L

    6.0/8.1L Electronic Ignition 4B - 13 Crankshaft Position (CKP) Sensor Replacement - 6.0L Removal Procedure 1. Remove the starter. 2. Disconnect the crankshaft position (CKP) sensor harness connector at the CKP sensor. Important: Clean the area around the CKP sensor before removal in order to avoid debris from entering the engine.

  • Page 136: Crankshaft Position (Ckp) Sensor Replacement - 8.1L

    4B - 14 Electronic Ignition 6.0/8.1L Crankshaft Position (CKP) Sensor Replacement - 8.1L Removal Procedure 1. Disconnect the crankshaft position (CKP) sensor harness connector at the CKP sensor. 674728 Important: Use penetrating oil, and allow the oil to soak around the CKP sensor prior to removing the sensor. 2.

  • Page 137: Camshaft Position (Cmp) Sensor Replacement - 6.0L

    6.0/8.1L Electronic Ignition 4B - 15 Camshaft Position (CMP) Sensor Replacement - 6.0L Removal Procedure 1. Remove the intake manifold. 2. Disconnect the camshaft position (CMP) sensor harness connector. Important: Clean the area around the CKP sensor before removal in order to avoid debris from entering the engine. 2.

  • Page 138: Camshaft Position (Cmp) Sensor Replacement - 8.1L

    4B - 16 Electronic Ignition 6.0/8.1L Camshaft Position (CMP) Sensor Replacement - 8.1L Removal Procedure 1. Disconnect the camshaft position (CMP) sensor harness connector (3) from the CMP sensor (1). 2. Remove the CMP sensor retaining bolt (2). 3. Remove the CMP sensor (1). 4.
  • Page 139 6.0/8.1L Electronic Ignition 4B - 17 4. Remove the knock sensors. 309864 Install or Connect Important • If installing a new knock sensor, be sure to replace with an identical part number. • When installing knock sensor, be sure to install in the same location removed from.

  • Page 140: Knock Sensor (Ks) 1 Replacement - 8.1L

    4B - 18 Electronic Ignition 6.0/8.1L Knock Sensor (KS) 1 Replacement - 8.1L Removal Procedure 1. Remove the wiring harness connector (1) from the knock sensor (2). 2. Remove the knock sensor (2) from the engine block. 678815 Installation Procedure 1.

  • Page 141: Knock Sensor (Ks) 2 Replacement - 8.1L

    6.0/8.1L Electronic Ignition 4B - 19 Knock Sensor (KS) 2 Replacement - 8.1L Removal Procedure 1. Remove the wiring harness connector from the knock sensor (2). 2. Remove the knock sensor (2) from the engine block (1). 20272 Installation Procedure 1.
  • Page 142 4B - 20 Electronic Ignition 6.0/8.1L This Page Left Intentionally Blank MEFI 4 - PCM...
  • Page 143 5.0/5.7/6.0/8.1L Diagnosis 5 - 1 Marine Electronic Fuel Injection (MEFI 4/4B) Section 5 Diagnosis This section will be used to perform diagnostic procedures on the Marine Electronic Fuel Injection (MEFI 4/4B) equipped engines. It describes the system circuits and diagnostic procedures used to diagnose the circuits. It will be used to correct Diagnostic Trouble Codes (DTCs) by following step-by-step procedures.
  • Page 144 5 - 2 Diagnosis 5.0/5.7/6.0/8.1L Diagnosis The diagnostic procedures and functional checks in this manual are designed to locate a faulty circuit or component through logic based on the process of elimination. The procedures are prepared with the requirement that the system functioned correctly at the time of assembly and that there are no multiple failures.

  • Page 145: Engine Controls

    5.0/5.7/6.0/8.1L Diagnosis 5 - 3 Engine Controls Specifi cations ECT Temperature vs. Resistance Values (Approximate) ECT Temperature vs. Resistance (cont’d) °C °F OHMS °C °F OHMS 2796 3520 4450 5670 7280 9420 1188 12300 1459 16180 1802 21450 2238 28680 52700 100700 Ignition System Specifi...
  • Page 146 5 - 4 Diagnosis 5.0/5.7/6.0/8.1L Fastener Tightening Specifi cations (5.0/5.7L) Specifi cations Application Metric English 9 N . m Camshaft Position (CMP) Sensor Bolt 72 lb in 9 N . m Crankshaft Position (CKP) Sensor Bolt 72 lb in 10-14 N . m Engine Control Module (ECM) Mounting Screws 88-124 lb in 17 N .
  • Page 147 5.0/5.7/6.0/8.1L Diagnosis 5 - 5 Important: A scan tool that displays faulty data should Engine Scan Tool Data List not be used. The scan tool problem should be reported to The Engine Scan Tool Data List contains all engine the manufacturer. Use of a faulty scan tool can result in related parameters that are available on the scan tool.
  • Page 148 5 - 6 Diagnosis 5.0/5.7/6.0/8.1L 6.0L MPI MEFI 4 - PCM...
  • Page 149 5.0/5.7/6.0/8.1L Diagnosis 5 - 7 8.1L MPI MEFI 4 - PCM...
  • Page 150 00.00-99.99 Hg - The Manifold Absolute Pressure (MAP) sensor. sensor measures the change in the intake manifold pressure Note: The 5.0L and 5.7L engines have an adjustable sensor. from engine load and speed changes. As intake manifold Moving the distributor on these applications changes the pressure increases, intake vacuum decreases resulting in Cam Retard, not ignition timing.
  • Page 151 5.0/5.7/6.0/8.1L Diagnosis 5 - 9 MANIFOLD AIR TEMPERATURE - Scan Tool Range -40°F WARNING BUZZER OUTPUT - Scan Tool Displays “ON” to 304°F - The ECM converts the resistance of the intake or “OFF” - Indicates the ECM commanded state of the air temperature sensor to degrees.
  • Page 152 5 - 10 Diagnosis 5.0/5.7/6.0/8.1L ECM Diagnostic Trouble Codes The Malfunction Indicator Lamp (MIL) will be “ON” if the malfunction exists under the conditions listed below. If the malfunction clears, the lamp will go out and the Diagnostic Trouble Code (DTC) will be stored in the ECM. Any DTC’s stored will be erased if no problem reoccurs within 50 engine starts.
  • Page 153 5.0/5.7/6.0/8.1L Diagnosis 5 - 11 Diagnostic Trouble Code (DTC) Table (cont’d) Description DTC 81 Crankshaft Position (CKP) Sensor Circuit Fault. Crank Signal Fault. (Hard or No Start, Backfi re, No Power) DTC 81 Camshaft Position (CMP) Sensor Circuit Fault. CAM Signal Fault. (No Symptom) DTC 81 DEPSPWR Circuit.
  • Page 154 5 - 12 Diagnosis 5.0/5.7/6.0/8.1L Clearing Diagnostic Trouble Codes - Scan Logged Warnings 1. Install scan tool. Using Diacom, these warnings will be displayed under the 2. Start engine. “‘Codes” tab. They can be cleared the same as the trouble 3.
  • Page 155 5.0/5.7/6.0/8.1L Diagnosis 5 - 13 To provide cleaner air, all gasoline in the United States Fuel System Specifi cations is now required to contain additives that will help prevent Use regular unleaded gasoline rated at 87 octane deposits from forming in your engine and fuel system, or higher.
  • Page 156 5 - 14 Diagnosis 5.0/5.7/6.0/8.1L MEFI 4 - PCM...
  • Page 157 5.0/5.7/6.0/8.1L Diagnosis 5 - 15 MEFI 4 - PCM...
  • Page 158 5 - 16 Diagnosis 5.0/5.7/6.0/8.1L MEFI 4 - PCM...
  • Page 159 5.0/5.7/6.0/8.1L Diagnosis 5 - 17 MEFI 4 - PCM...
  • Page 160 5 - 18 Diagnosis 5.0/5.7/6.0/8.1L MEFI 4 - PCM...
  • Page 161 5.0/5.7/6.0/8.1L Diagnosis 5 - 19 Camshaft Solid Crankshaft Position State Position (CMP) Solid (CKP) Sensor State Sensor S105 S104 PNK/BLK BRN/WHT 633 LT GRN 634 PNK/ RED 631 Engine Control CKP Sensor DepsLo Depspower CMP Sensor Module Signal Signal (ECM) 8.1L Engine Camshaft Solid...
  • Page 162 5 - 20 Diagnosis 5.0/5.7/6.0/8.1L MEFI 4 - PCM...
  • Page 163 5.0/5.7/6.0/8.1L Diagnosis 5 - 21 MEFI 4 - PCM...
  • Page 164 5 - 22 Diagnosis 5.0/5.7/6.0/8.1L MEFI 4 - PCM...
  • Page 165 5.0/5.7/6.0/8.1L Diagnosis 5 - 23 MEFI 4 - PCM...
  • Page 166 5 - 24 Diagnosis 5.0/5.7/6.0/8.1L MEFI 4 - PCM...
  • Page 167 5.0/5.7/6.0/8.1L Diagnosis 5 - 25 MEFI 4 - PCM...
  • Page 168 5 - 26 Diagnosis 5.0/5.7/6.0/8.1L MEFI 4 - PCM...
  • Page 169 5.0/5.7/6.0/8.1L Diagnosis 5 - 27 This Page Was Intentionally Left Blank MEFI 4 - PCM...
  • Page 170 5 - 28 Diagnosis 5.0/5.7/6.0/8.1L MEFI 4 - PCM...
  • Page 171 5.0/5.7/6.0/8.1L Diagnosis 5 - 29 MEFI 4 - PCM...
  • Page 172 5 - 30 Diagnosis 5.0/5.7/6.0/8.1L MEFI 4 - PCM...
  • Page 173 5.0/5.7/6.0/8.1L Diagnosis 5 - 31 MEFI 4 - PCM...
  • Page 174 5 - 32 Diagnosis 5.0/5.7/6.0/8.1L MEFI 4 - PCM...
  • Page 175 5.0/5.7/6.0/8.1L Diagnosis 5 - 33 MEFI 4 - PCM...
  • Page 176 5 - 34 Diagnosis 5.0/5.7/6.0/8.1L MEFI 4 - PCM...
  • Page 177 5.0/5.7/6.0/8.1L Diagnosis 5 - 35 This Page Was Intentionally Left Blank MEFI 4 - PCM...
  • Page 178 5 - 36 Diagnosis 5.0/5.7/6.0/8.1L ECM Connector Pinout Identifi cation (1 of 2) (5.0/5.7L) 15 14 13 12 11 10 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 ECM 32 WAY CONNECTOR ECM PIN CKT(WIRE) CKT (WIRE)
  • Page 179 5.0/5.7/6.0/8.1L Diagnosis 5 - 37 ECM Connector Pinout Identifi cation (2 of 2) (5.0/5.7L) 15 14 13 12 11 10 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 ECM 32 WAY CONNECTOR ECM PIN CKT(WIRE) CKT (WIRE)
  • Page 180 5 - 38 Diagnosis 5.0/5.7/6.0/8.1L ECM Connector Pinout Identifi cation (1 of 2) (6.0/8.1L) 15 14 13 12 11 10 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 ECM 32 WAY CONNECTOR ECM PIN CKT(WIRE) CKT (WIRE)
  • Page 181 5.0/5.7/6.0/8.1L Diagnosis 5 - 39 ECM Connector Pinout Identifi cation (2 of 2) (6.0/8.1L) 15 14 13 12 11 10 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 ECM 32 WAY CONNECTOR ECM PIN CKT(WIRE) CKT (WIRE)
  • Page 182 5 - 40 Diagnosis 5.0/5.7/6.0/8.1L Camshaft Position (CMP) Sensor (8.1L) Crankshaft Position (CKP) Sensor (8.1L) 366117 684840 Connector Part • Connector Part • 12129946 15324165 Information Information • • 3-Way F Metri-Pack 3-Way F Metri-Pack 150 Series Sealed 150 Series Sealed Wire Circuit Wire...
  • Page 183 5.0/5.7/6.0/8.1L Diagnosis 5 - 41 Fuel Injector #3 (6.0/8.1L) Fuel Injector #4 (6.0/8.1L) 684833 684833 Connector Part Connector Part • • 12129140 12129140 Information Information • • 2-Way F Metri-Pack 280.1 2-Way F Metri-Pack 280.1 P2S (BLK) P2S (BLK) Wire Circuit Wire Circuit...
  • Page 184 5 - 42 Diagnosis 5.0/5.7/6.0/8.1L Fuel Injector #7 (6.0/8.1L) Fuel Injector #8 (6.0/8.1L) 684833 684833 Connector Part Connector Part • • 12129140 12129140 Information Information • • 2-Way F Metri-Pack 280.1 2-Way F Metri-Pack 280.1 P2S (BLK) P2S (BLK) Wire Circuit Wire Circuit...
  • Page 185 5.0/5.7/6.0/8.1L Diagnosis 5 - 43 Ignition Coil/Driver - Cylinder #5 (6.0/8.1L) Ignition Coil/Driver - Cylinder #7 (6.0/8.1L) 684854 684854 Connector Part Connector Part • • 12162144 12162144 Information Information • • 4-Way F Metri-Pack 4-Way F Metri-Pack 150 Series Sealed (BLK) 150 Series Sealed (BLK) Wire Circuit...
  • Page 186 5 - 44 Diagnosis 5.0/5.7/6.0/8.1L Ignition Coil/Driver - Cylinder #6 (6.0/8.1L) Ignition Coil/Driver - Cylinder #8 (6.0/8.1L) 684854 684854 Connector Part Connector Part • • 12162144 12162144 Information Information • • 4-Way F Metri-Pack 4-Way F Metri-Pack 150 Series Sealed (BLK) 150 Series Sealed (BLK) Wire Circuit...
  • Page 187 5.0/5.7/6.0/8.1L Diagnosis 5 - 45 Knock Sensor, LH - Odd (6.0/8.1L) Knock Sensor, RH - Even (6.0/8.1L) 35437 35437 Connector Part Connector Part • • 15355362 15355362 Information Information • • 1-Way F Metri-Pack 1-Way F Metri-Pack 150 Series Sealed (NAT) 150 Series Sealed (NAT) Wire Circuit...
  • Page 188 5 - 46 Diagnosis 5.0/5.7/6.0/8.1L Alternator Starter Solenoid From Pin #5 10-pin Boat To Pin #6 Harness 10-pin Boat (Ignition) Circuit Harness Breaker Alternator PPL/ ”A” To Fuel Alternator Starter Relay S107 S108 ”B” Term. "30" (6.0/8.1L) Fuse Block RED/ WHT 2 ECM/BAT Fuse 20A...
  • Page 189 5.0/5.7/6.0/8.1L Diagnosis 5 - 47 Test Description (continued) 9. A scan tool parameter which is not within the typical range may help to isolate the area which is causing the 6. When you return to the Diacom ‘Tests’ menu to disable problem.
  • Page 190 5 - 48 Diagnosis 5.0/5.7/6.0/8.1L On-Board Diagnostic (OBD) System Check - Scan (cont’d) Step Action Value 1. On the Diacom screen select the ‘Tests’ tab, and select “Activate Base Timing Mode .” 2. Select Diacom, ‘ECM Data’ display. 3. Ignition “ON,” engine “OFF.” 4.
  • Page 191 5.0/5.7/6.0/8.1L Diagnosis 5 - 49 This Page Was Intentionally Left Blank MEFI 4 - PCM...
  • Page 192 5 - 50 Diagnosis 5.0/5.7/6.0/8.1L Alternator Starter Solenoid From Pin #5 10-pin Boat To Pin #6 Harness 10-pin Boat (Ignition) Circuit Harness Breaker Alternator PPL/ ”A” To Fuel Alternator Starter Relay S107 S108 ”B” Term. "30" (6.0/8.1L) Fuse Block RED/ WHT 2 ECM/BAT Fuse 20A...
  • Page 193 5.0/5.7/6.0/8.1L Diagnosis 5 - 51 Diagnostic Procedure (DP) A-1 - No Malfunction Indicator Lamp (MIL) - Diagnostic Trouble Code (DTC) Tool Installed Step Action Value Was the “On-Board Diagnostic” (OBD) System Check Go to OBD performed? — Go to Step 2 System Check Attempt to start the engine.
  • Page 194 5 - 52 Diagnosis 5.0/5.7/6.0/8.1L Diagnostic Procedure (DP) A-1 - No Malfunction Indicator Lamp (MIL) - Diagnostic Trouble Code (DTC) Tool Installed Step Action Value Locate and repair open in CKT 419. Go to OBD Is action complete? — System Check —- Locate and repair short to ground in CKT 440, then replace the fuse.
  • Page 195 5.0/5.7/6.0/8.1L Diagnosis 5 - 53 This Page Was Intentionally Left Blank MEFI 4 - PCM...
  • Page 196 5 - 54 Diagnosis 5.0/5.7/6.0/8.1L Alternator Starter Solenoid From Pin #5 10-pin Boat To Pin #6 Harness 10-pin Boat (Ignition) Circuit Harness Breaker Alternator PPL/ ”A” To Fuel Alternator Starter Relay S107 S108 ”B” Term. "30" (6.0/8.1L) Fuse Block RED/ WHT 2 ECM/BAT Fuse 20A...
  • Page 197 5.0/5.7/6.0/8.1L Diagnosis 5 - 55 Diagnostic Procedure (DP) A-2 - Malfunction Indicator Lamp (MIL) “On” Steady - Will Not Flash DTC 12 - Diagnostic Trouble Code (DTC) Tool Installed Step Action Value Was the “On-Board Diagnostic” (OBD) System Check Go to OBD performed? —...
  • Page 198 5 - 56 Diagnosis 5.0/5.7/6.0/8.1L Battery Powered Timing Light Fuel Pressure Gauge M4051 9-18-02 Diagnostic Procedure (DP) A-3 - Engine Cranks But Will Not Run Circuit Description Diagnostic Aids In the Ignition system and the fuel injector circuit, the An intermittent may be caused by a poor connection, supply voltage comes from the MEFI system relay.
  • Page 199 5.0/5.7/6.0/8.1L Diagnosis 5 - 57 Test Description 6. No spark may be caused by one of several components related to the ignition system. The ignition system Number(s) below refer to the Step number(s) on the check will address all problems related to the causes Diagnostic Table: of a no spark condition.
  • Page 200 5 - 58 Diagnosis 5.0/5.7/6.0/8.1L Diagnostic Procedure (DP) A-3 - Engine Cranks But Will Not Run Step Action Value Perform the following additional inspections: • Inspect that the throttle angle is at 0% at a closed throttle. If the throttle angle is not at 0%, refer to DTC 21 Throttle Position (TP) Sensor Circuit High Voltage or DTC 22 Throttle Position (TP) Sensor Circuit Low Voltage.
  • Page 201 5.0/5.7/6.0/8.1L Diagnosis 5 - 59 This Page Was Intentionally Left Blank MEFI 4 - PCM...
  • Page 202 5 - 60 Diagnosis 5.0/5.7/6.0/8.1L PRESSURE REGULATOR Fuel Control Cell Fuel System FUEL RAIL ASSEMBLY LOW- FUEL PRESSURE FILTER FUEL FUEL PUMP ENGINE CONTROL CELL FUEL TANK Fuel Control Cell Fuel System FUEL RAIL ASSEMBLY (Returnless Fuel Rail) LOW- PRESS. FUEL PRESSURE REG.
  • Page 203 5.0/5.7/6.0/8.1L Diagnosis 5 - 61 12. A rich condition may result from the fuel pressure Check the spark plug associated with a particular being above the required value. See the Master fuel injector for fouling or saturation in order to Specifi...
  • Page 204 5 - 62 Diagnosis 5.0/5.7/6.0/8.1L Diagnostic Procedure (DP) A-4 Fuel System Diagnosis (cont’d) Step Action Value Important: The fuel pressure may vary slightly when the fuel pump stops running. After the fuel pump stops running, the fuel pressure should stabilize and remain constant.
  • Page 205 5.0/5.7/6.0/8.1L Diagnosis 5 - 63 Diagnostic Procedure (DP) A-4 Fuel System Diagnosis (cont’d) Step Action Value 1. Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure. 2. Disconnect the fuel feed pipe and the fuel return pipe from the fuel rail. 3.
  • Page 206 5 - 64 Diagnosis 5.0/5.7/6.0/8.1L Diagnostic Procedure (DP) A-4 Fuel System Diagnosis Step Action Value 1. Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure. 2. Disconnect the fuel return pipe from the fuel rail. 3. Install the J 37287 fuel pipe shut-off adapter between the fuel return pipe and the fuel rail.
  • Page 207 5.0/5.7/6.0/8.1L Diagnosis 5 - 65 This Page Was Intentionally Left Blank MEFI 4 - PCM...
  • Page 208 5 - 66 Diagnosis 5.0/5.7/6.0/8.1L To DLC Connector Term. "C" S117 S116 Low Pressure Fuel Pump Fuel Control GRY 120 Cell S118 Not Used S119 Fuel Pump Relay DK GRN 485 Fuse Block PNK/ From S107 PNK 439 (B+) Fuel Pump Relay Fuse From S122...
  • Page 209 5.0/5.7/6.0/8.1L Diagnosis 5 - 67 Diagnostic Procedure (DP) A-5 Fuel Pump Relay Circuit Diagnosis Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Check the fuel pump relay fuse. Is the fuse open? —...
  • Page 210 5 - 68 Diagnosis 5.0/5.7/6.0/8.1L Diagnostic Procedure (DP) A-5 Fuel Pump Relay Circuit Diagnosis Step Action Value Probe the battery feed circuit for the fuel pump relay at the harness connector with a test lamp J 34142-B connected to B+. Does the test lamp illuminate? —...
  • Page 211 5.0/5.7/6.0/8.1L Diagnosis 5 - 69 Diagnostic Procedure (DP) A-5 Fuel Pump Relay Circuit Diagnosis Step Action Value Inspect for a poor connection at the ECM. Did you fi nd and correct the condition? — Go to Step 26 Go to Step 23 Replace the ECM.
  • Page 212 5 - 70 Diagnosis 5.0/5.7/6.0/8.1L Alternator Starter Solenoid Circuit Breaker To Alternator From Connector S108 Term. "A" (Ignition) To Pin #6 10-pin Boat To Starter Harness S107 Relay Term. "30" PPL/ Fuse Block RED/ WHT 2 ECM/BAT Fuse 20A MEFI To DLC System Connector...
  • Page 213 5.0/5.7/6.0/8.1L Diagnosis 5 - 71 Diagnostic Procedure (DP) A-6 System Relay Diagnosis Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check 1. Turn OFF the ignition. 2. Disconnect the system relay electrical connector. 3.
  • Page 214 5 - 72 Diagnosis 5.0/5.7/6.0/8.1L From S122 From S122 Located Right Side of Front Located Inside Cover Distributor Magnetic Used Pickup Camshaft Mounted on Crankshaft Solid Position Ignition Coil Position State (CMP) (CKP) Distributor Ignition Coil Driver Sensor Sensor Ignition Voltage Solid State...
  • Page 215 5.0/5.7/6.0/8.1L Diagnosis 5 - 73 Diagnostic Procedure (DP) A-7A Distributor Ignition Diagnosis (5.0/5.7L Only) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Caution: Before proceeding, remove all injector connectors and the ignition module connector (5.0/5.7L), or disconnect the harness connectors at the ignition coils and the injectors(6.0/8.1L) in order to prevent...
  • Page 216 5 - 74 Diagnosis 5.0/5.7/6.0/8.1L Diagnostic Procedure (DP) A-7A Distributor Ignition Diagnosis (5.0/5.7L Only) Step Action Value 1. Turn the ignition “OFF.” 2. Using a test lamp connected to B+, probe the ignition coil driver circuit, terminal “C.” Does the test lamp illuminate brightly? —...
  • Page 217 5.0/5.7/6.0/8.1L Diagnosis 5 - 75 Diagnostic Procedure (DP) A-7A Distributor Ignition Diagnosis (5.0/5.7L Only) Step Action Value Using a test lamp connected to B+, probe the ignition timing control circuit at the ECM harness connector, “J2-31.” Does the test lamp illuminate brightly? —...
  • Page 218 5 - 76 Diagnosis 5.0/5.7/6.0/8.1L Diagnostic Procedure (DP) A-7A Distributor Ignition Diagnosis (5.0/5.7L Only) Step Action Value Locate and repair the short to ground in the coil driver circuit between the ignition coil and the IC module. Is action complete? —...
  • Page 219 5.0/5.7/6.0/8.1L Diagnosis 5 - 77 This Page Was Intentionally Left Blank MEFI 4 - PCM...
  • Page 220 5 - 78 Diagnosis 5.0/5.7/6.0/8.1L Hot in Run And Start From System Relay Term. "87" PPL 902 To Fuse Block S121 Term. "A" To Ignition Coil Connector (even cyl.) Fuse Block Term. "H" INJ/ECM Fuse To Fuel Pump PNK 439 Relay Term.
  • Page 221 5.0/5.7/6.0/8.1L Diagnosis 5 - 79 Diagnostic Procedure (DP) A-7B Electronic Ignition System Diagnosis (6.0/8.1L Only) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Important: If all the Ignition Control (IC) DTCs are set at the same time, inspect the IC ground circuits for an open.
  • Page 222 5 - 80 Diagnosis 5.0/5.7/6.0/8.1L Idle Air Stepper Motor Control (IAC) Valve Coil Coil GRN/WHT 443 BLU/ WHT 442 GRN/ BLU/BLK 441 Engine Control Coil B Coil B Coil A Coil A Module High High (ECM) M4059 9-18-02 Diagnostic Procedure (DP) A-8 Idle Air Control Functional Test •...
  • Page 223 5.0/5.7/6.0/8.1L Diagnosis 5 - 81 Diagnostic Procedure (DP) A-8 Idle Air Control Functional Test Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check 1. Ignition “OFF” for 10 seconds. 2.
  • Page 224 5 - 82 Diagnosis 5.0/5.7/6.0/8.1L Engine Control Module (ECM) Sensor Signal 7 J2 YEL 410 Engine Coolant Temperature (ECT) Sensor From TP Sensor BLK 814 From MAP Sensor S123 BLK 814 Sensor Ground DTC 14 - Engine Coolant Temperature (ECT) Sensor Circuit - Low Temp Indicated (Scan Diagnostics) (High Voltage) •...
  • Page 225 5.0/5.7/6.0/8.1L Diagnosis 5 - 83 DTC 14 - Engine Coolant Temperature (ECT) Sensor Circuit - Low Temp Indicated (Scan Diagnostics) (High Voltage) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Turn ignition ON, leaving engine OFF.
  • Page 226 5 - 84 Diagnosis 5.0/5.7/6.0/8.1L Engine Control Module (ECM) Sensor Signal 7 J2 YEL 410 Engine Coolant Temperature (ECT) Sensor From TP Sensor BLK 814 From MAP Sensor S123 BLK 814 Sensor Ground DTC 15 - Engine Coolant Temperature (ECT) Sensor Circuit - High Temp Indicated (Scan Diagnostics) (Low Voltage) •...
  • Page 227 5.0/5.7/6.0/8.1L Diagnosis 5 - 85 DTC 15 - Engine Coolant Temperature (ECT) Sensor Circuit - High Temp Indicated (Scan Diagnostics) (Low Voltage) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Turn ignition ON, leaving engine OFF.
  • Page 228 5 - 86 Diagnosis 5.0/5.7/6.0/8.1L Engine Control Module (ECM) 5 Volt Reference To MAP S125 Sensor 416E From ECT GRY 416 Sensor Throttle Position(TP) Sensor BLK 814 From MAP Sensor S123 BLK 814 DK BLU 417 Engine TP Sensor Sensor Control Signal Ground...
  • Page 229 5.0/5.7/6.0/8.1L Diagnosis 5 - 87 DTC 21 - Throttle Position (TP) Sensor Circuit - Signal Voltage High (Scan Diagnostics) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check 1.
  • Page 230 5 - 88 Diagnosis 5.0/5.7/6.0/8.1L Engine Control Module (ECM) 5 Volt Reference To MAP S125 Sensor 416E From ECT GRY 416 Sensor Throttle Position(TP) Sensor BLK 814 From MAP Sensor S123 BLK 814 DK BLU 417 Engine TP Sensor Sensor Control Signal Ground...
  • Page 231 5.0/5.7/6.0/8.1L Diagnosis 5 - 89 DTC 22 - Throttle Position (TP) Sensor Circuit - Signal Voltage Low (Scan Diagnostics) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check 1.
  • Page 232 5 - 90 Diagnosis 5.0/5.7/6.0/8.1L Engine Control Module (ECM) IAT Sensor 5 Volt Signal Reference 2 J2 S125 GRY 416E GRY 416 PPL 472 To TP Manifold Sensor Absolute Pressure From ECT (MAP)/Intake Sensor Air Temperature From TP (IAT) Sensor Sensor (5.0/5.7L) BLK 814...
  • Page 233 5.0/5.7/6.0/8.1L Diagnosis 5 - 91 DTC 23 - Intake Air Temperature (IAT) Sensor Circuit - Low Temp Indicated (5.0/5.7L Only) (Scan Diagnostics) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Turn ignition ON, leaving engine OFF.
  • Page 234 5 - 92 Diagnosis 5.0/5.7/6.0/8.1L Engine Control Module (ECM) IAT Sensor 5 Volt Signal Reference 2 J2 S125 GRY 416E GRY 416 PPL 472 To TP Manifold Sensor Absolute Pressure From ECT (MAP)/Intake Sensor Air Temperature From TP (IAT) Sensor Sensor (5.0/5.7L) BLK 814...
  • Page 235 5.0/5.7/6.0/8.1L Diagnosis 5 - 93 DTC 25 - Intake Air Temperature (IAT) Sensor Circuit - High Temp Indicated (5.0/5.7L Only) (Scan Diagnostics) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Turn ignition ON, leaving engine OFF.
  • Page 236 5 - 94 Diagnosis 5.0/5.7/6.0/8.1L Engine Control Module (ECM) IAT Sensor 5 Volt Signal Reference Engine Control 2 J2 Module 5 Volt (ECM) S125 Reference GRY 416E 2 J2 GRY 416 PPL 472 S125 GRY 416E To TP GRY 416 Manifold Sensor Absolute...
  • Page 237 5.0/5.7/6.0/8.1L Diagnosis 5 - 95 DTC 33 - Manifold Absolute Pressure (MAP) Sensor Circuit - Signal Voltage High (Scan Diagnostics) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check 1.
  • Page 238 5 - 96 Diagnosis 5.0/5.7/6.0/8.1L Engine Control Module (ECM) IAT Sensor 5 Volt Signal Reference Engine Control 2 J2 Module 5 Volt (ECM) S125 Reference GRY 416E 2 J2 GRY 416 PPL 472 S125 GRY 416E To TP GRY 416 Manifold Sensor Absolute...
  • Page 239 5.0/5.7/6.0/8.1L Diagnosis 5 - 97 DTC 34 - Manifold Absolute Pressure (MAP) Sensor Circuit - Signal Voltage Low (Scan Diagnostics) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check 1.
  • Page 240 5 - 98 Diagnosis 5.0/5.7/6.0/8.1L From S122 (ignition) From S122 (ignition) Used Mounted on Ignition Coil Distributor Ignition Coil Driver Ignition Voltage Control Ignition Module Coil (ICM) Ignition Control Ground Signal GRY 2121 Coil Wire 31 J2 Engine IC Control Control Module High...
  • Page 241 5.0/5.7/6.0/8.1L Diagnosis 5 - 99 DTC 41 (EST A Fault) - Ignition Control Circuit (5.0/5.7L ONLY) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check 1. Turn ignition “ON,” engine “OFF.” 2.
  • Page 242 5 - 100 Diagnosis 5.0/5.7/6.0/8.1L Hot in Run And Start From System Relay Term. "87" PPL 902 To Fuse Block S121 Term. "A" To Ignition Coil Connector (even cyl.) Fuse Block Term. "H" INJ/ECM Fuse To Fuel Pump PNK 439 Relay Term.
  • Page 243 5.0/5.7/6.0/8.1L Diagnosis 5 - 101 DTC 41 (EST A Fault) - Ignition Coil 1 Control Circuit (6.0/8.1L) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Important: If all the Ignition Control (IC) DTCs are set at the same time, inspect the IC ground circuits for an open.
  • Page 244 5 - 102 Diagnosis 5.0/5.7/6.0/8.1L Hot in Run And Start From System Relay Term. "87" PPL 902 To Fuse Block S121 Term. "A" To Ignition Coil Connector (even cyl.) Fuse Block Term. "H" INJ/ECM Fuse To Fuel Pump PNK 439 Relay Term.
  • Page 245 5.0/5.7/6.0/8.1L Diagnosis 5 - 103 DTC 41 (EST D Fault) - Ignition Coil 2 Control Circuit (6.0/8.1L) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Important: If all the Ignition Control (IC) DTCs are set at the same time, inspect the IC ground circuits for an open.
  • Page 246 5 - 104 Diagnosis 5.0/5.7/6.0/8.1L Hot in Run And Start From System Relay Term. "87" PPL 902 To Fuse Block S121 Term. "A" To Ignition Coil Connector (even cyl.) Fuse Block Term. "H" INJ/ECM Fuse To Fuel Pump PNK 439 Relay Term.
  • Page 247 5.0/5.7/6.0/8.1L Diagnosis 5 - 105 DTC 41 (EST H Fault) - Ignition Coil 3 Control Circuit (6.0/8.1L) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Important: If all the Ignition Control (IC) DTCs are set at the same time, inspect the IC ground circuits for an open.
  • Page 248 5 - 106 Diagnosis 5.0/5.7/6.0/8.1L Hot in Run And Start From System Relay Term. "87" PPL 902 To Fuse Block S121 Term. "A" To Ignition Coil Connector (even cyl.) Fuse Block Term. "H" INJ/ECM Fuse To Fuel Pump PNK 439 Relay Term.
  • Page 249 5.0/5.7/6.0/8.1L Diagnosis 5 - 107 DTC 41 (EST G Fault) - Ignition Coil 4 Control Circuit (6.0/8.1L) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Important: If all the Ignition Control (IC) DTCs are set at the same time, inspect the IC ground circuits for an open.
  • Page 250 5 - 108 Diagnosis 5.0/5.7/6.0/8.1L Hot in Run And Start From System Relay Term. "87" PPL 902 To Fuse Block S121 Term. "A" To Ignition Coil Connector (even cyl.) Fuse Block Term. "H" INJ/ECM Fuse To Fuel Pump PNK 439 Relay Term.
  • Page 251 5.0/5.7/6.0/8.1L Diagnosis 5 - 109 DTC 41 (EST F Fault) - Ignition Coil 5 Control Circuit (6.0/8.1L) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Important: If all the Ignition Control (IC) DTCs are set at the same time, inspect the IC ground circuits for an open.
  • Page 252 5 - 110 Diagnosis 5.0/5.7/6.0/8.1L Hot in Run And Start From System Relay Term. "87" PPL 902 To Fuse Block S121 Term. "A" To Ignition Coil Connector (even cyl.) Fuse Block Term. "H" INJ/ECM Fuse To Fuel Pump PNK 439 Relay Term.
  • Page 253 5.0/5.7/6.0/8.1L Diagnosis 5 - 111 DTC 41 (EST E Fault) - Ignition Coil 6 Control Circuit (6.0/8.1L) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Important: If all the Ignition Control (IC) DTCs are set at the same time, inspect the IC ground circuits for an open.
  • Page 254 5 - 112 Diagnosis 5.0/5.7/6.0/8.1L Hot in Run And Start From System Relay Term. "87" PPL 902 To Fuse Block S121 Term. "A" To Ignition Coil Connector (even cyl.) Fuse Block Term. "H" INJ/ECM Fuse To Fuel Pump PNK 439 Relay Term.
  • Page 255 5.0/5.7/6.0/8.1L Diagnosis 5 - 113 DTC 41 (EST C Fault) - Ignition Coil 7 Control Circuit (6.0/8.1L) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Important: If all the Ignition Control (IC) DTCs are set at the same time, inspect the IC ground circuits for an open.
  • Page 256 5 - 114 Diagnosis 5.0/5.7/6.0/8.1L Hot in Run And Start From System Relay Term. "87" PPL 902 To Fuse Block S121 Term. "A" To Ignition Coil Connector (even cyl.) Fuse Block Term. "H" INJ/ECM Fuse To Fuel Pump PNK 439 Relay Term.
  • Page 257 5.0/5.7/6.0/8.1L Diagnosis 5 - 115 DTC 41 (EST B Fault) - Ignition Coil 8 Control Circuit (6.0/8.1L) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Important: If all the Ignition Control (IC) DTCs are set at the same time, inspect the IC ground circuits for an open.
  • Page 258 5 - 116 Diagnosis 5.0/5.7/6.0/8.1L Engine Control Module (ECM) Knock Knock Sensor 1 Sensor 2 Signal Signal LT BLU/ DK BLU 467 (6.0L only) Knock Knock Sensor 1 Sensor 2 (KS) (KS) (6.0/8.1L Only) M4063 3-2-04 DTC 44 - Knock Sensor (KS) 1 Circuit (Scan Diagnostics) Circuit Description Test Description The ECM uses the Knock Sensor(s) in order to detect engine...
  • Page 259 5.0/5.7/6.0/8.1L Diagnosis 5 - 117 DTC 44 - Knock Sensor (KS) 1 Circuit (Scan Diagnostics) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Important: If you can hear the engine knock, repair the engine mechanical problem before proceeding with this diagnostic table.
  • Page 260 5 - 118 Diagnosis 5.0/5.7/6.0/8.1L Engine Control Module Knock (ECM) Knock Sensor 1 Sensor 2 Signal Signal LT BLU/ DK BLU 467 (6.0L only) Knock Knock Sensor 1 Sensor 2 (KS) (KS) (6.0/8.1L Only) M4063 3-2-04 DTC 44 - Knock Sensor (KS) 2 Circuit (Scan Diagnostics) (6.0/8.1L Only) Circuit Description Test Description The ECM uses the Knock Sensor(s) in order to detect engine...
  • Page 261 5.0/5.7/6.0/8.1L Diagnosis 5 - 119 DTC 44 - Knock Sensor (KS) 2 Circuit (Scan Diagnostics) (6.0/8.1L Only) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Important: If you can hear the engine knock, repair the engine mechanical problem before proceeding with this diagnostic procedure.
  • Page 262 5 - 120 Diagnosis 5.0/5.7/6.0/8.1L MEFI3004 DTC 51 - Calibration Checksum Failure (Scan Diagnostics) Circuit Description Diagnostic Aids This test allows the ECM to check for a calibration failure If DTC 51 failed more than once, but is intermittent, replace by comparing the calibration value to a known value stored the ECM.
  • Page 263 5.0/5.7/6.0/8.1L Diagnosis 5 - 121 This Page Was Intentionally Left Blank MEFI 4 - PCM...
  • Page 264 5 - 122 Diagnosis 5.0/5.7/6.0/8.1L Engine Control Module Exhaust (ECM) Temperature Switch Input Exhaust Exhaust Temperature Temperature Switch Switch (Port) (Starboard) M4095 2-27-04 DTC 81 - Exhaust Temperature Switch (ETS) Circuit - High Temp. Indicated (Scan Diagnostics) Circuit Description • Corrosion The Exhaust Temperature Switch (ETS) circuit monitors for a •...
  • Page 265 5.0/5.7/6.0/8.1L Diagnosis 5 - 123 DTC 81 - Exhaust Temperature Switch (ETS) Circuit - High Temp. Indicated (Scan Diagnostics) Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check Verify proper cooling system operation, including raw water pump volume test.
  • Page 266 5 - 124 Diagnosis 5.0/5.7/6.0/8.1L 5.0/5.7/8.1L 6.0L Solid Crankshaft Solid Crankshaft State Position State Position (CKP) (CKP) Sensor Sensor To CMP To CMP Sensor S105 Sensor S105 LT GRN 634 S104 LT GRN 634 S104 To CMP PNK/BLK To CMP PNK/BLK Sensor Sensor...
  • Page 267 5.0/5.7/6.0/8.1L Diagnosis 5 - 125 DTC 81 - Crankshaft Position (CKP) Sensor Circuit Fault Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check 1. Install a scan tool. 2.
  • Page 268 5 - 126 Diagnosis 5.0/5.7/6.0/8.1L DTC 81 - Crankshaft Position (CKP) Sensor Circuit Fault (cont’d) Step Action Value 3. Using a DMM connected to a known good ground, probe the sensor signal circuit at the CKP sensor. (5.0/5.7/8.1L) - Sensor terminal “C.” (6.0L) - Sensor terminal “A.”...
  • Page 269 5.0/5.7/6.0/8.1L Diagnosis 5 - 127 This Page Was Intentionally Left Blank MEFI 4 - PCM...
  • Page 270 5 - 128 Diagnosis 5.0/5.7/6.0/8.1L Camshaft Solid Position State (CMP) Sensor (8.1L) To CKP Sensor S105 S104 To CKP PNK/BLK Sensor BRN/WHT 633 RED 631 PNK/ Engine Control Module DepsLo Depspower CMP Sensor (ECM) Signal M4079 9-29-02 Located Inside Distributor Camshaft Solid Position...
  • Page 271 5.0/5.7/6.0/8.1L Diagnosis 5 - 129 Circuit Description Diagnostic Aids The CMP sensor works in conjunction with a 1X reluctor Check for the following conditions: wheel on the camshaft (6.0/8.1L), or the distributor shaft • Camshaft reluctor wheel damage (5.7L). The CMP sensor is a three-wire sensor; 12 volt •...
  • Page 272 5 - 130 Diagnosis 5.0/5.7/6.0/8.1L DTC 81 - Camshaft Position (CMP) Sensor Circuit Fault Step Action Value Using a DMM, measure the voltage between the CMP sensor harness connector terminals “A” (8.1L), or “C” (5.0/5.7L) (Depspower) and “B” (8.1L), or “A” (5.0/5.7/6.0L) (Depslo).
  • Page 273 5.0/5.7/6.0/8.1L Diagnosis 5 - 131 DTC 81 - Camshaft Position (CMP) Sensor Circuit Fault (cont’d) Step Action Value 1. Remove the CMP sensor. 2. Visually inspect the CMP sensor for physical damage, loose or improper installation or wiring routed too close to secondary ignition components.
  • Page 274 5 - 132 Diagnosis 5.0/5.7/6.0/8.1L Crankshaft Crankshaft Camshaft Position Camshaft Solid Position Solid Solid Position (CKP) Solid Position State (CKP) State State (CMP) State Sensor (CMP) Sensor Sensor (8.1L) (6.0L) Sensor (6.0L) S105 S105 LT GRN 634 S104 LT GRN 634 S104 PNK/BLK PNK/BLK...
  • Page 275 5.0/5.7/6.0/8.1L Diagnosis 5 - 133 DTC 81 - Depspower Circuit Out of Range Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check 1. Disconnect the ECM harness connector J2. 2.
  • Page 276 5 - 134 Diagnosis 5.0/5.7/6.0/8.1L Engine Control Module (ECM) 5 Volt Reference S125 GRY 416E GRY 416 To MAP Sensor Term. "C" (6.0/8.1L) To TP To MAP/IAT Sensor Sensor Term. Term. "A" "3" (5.0/5.7L) M4083 2-10-04 DTC 81 - 5 Volt Reference Circuit Out of Range Circuit Description Test Description The Engine Control Module (ECM) uses a common 5 volt...
  • Page 277 5.0/5.7/6.0/8.1L Diagnosis 5 - 135 DTC 81 - 5 Volt Reference Circuit Out of Range Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check 1. Turn ON the ignition, with the engine OFF. 2.
  • Page 278 5 - 136 Diagnosis 5.0/5.7/6.0/8.1L To DLC Connector Term. "C" S117 S116 Low Press. Fuel Pump Fuel Control Cell GRY 120 S119 Not Used Fuel Pump From Relay Starter Relay Term. "85" Fuse Block DK GRN/ PNK 339 From RED/ S107 WHT 2 (B+)
  • Page 279 5.0/5.7/6.0/8.1L Diagnosis 5 - 137 DTC 81 - Fuel Pump Relay Driver Circuit High, Low or Open Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check 1. Turn ON the ignition, with the engine OFF. 2.
  • Page 280 5 - 138 Diagnosis 5.0/5.7/6.0/8.1L DTC 81 - Fuel Pump Relay Driver Circuit High, Low or Open (cont’d) Step Action Value Locate and repair faulty connections at the relay. Was a problem found? — Verify Repair Go to Step 12 Locate and repair faulty connections at the ECM.
  • Page 281 5.0/5.7/6.0/8.1L Diagnosis 5 - 139 This Page Was Intentionally Left Blank MEFI 4 - PCM...
  • Page 282 5 - 140 Diagnosis 5.0/5.7/6.0/8.1L Hot in Run And Start From S121 Fuse Block To ECM Term To Fuel Pump "J2-19"" INJ/ECM Fuse Relay Term. "86" S122 To Ignition Coil Connector (odd cyl.) Term. "H" PNK 439 To Ignition Coil Connector (even cyl.) S126 Term.
  • Page 283 5.0/5.7/6.0/8.1L Diagnosis 5 - 141 Hot in Run And Start From S121 Fuse Block To ECM Term To Fuel Pump "J2-19"" INJ/ECM Fuse Relay Term. "86" S122 To Ignition Module Connector Term. "A" PNK 439 To Ignition Coil Connector Term. "A" PNK 439 Fuel Fuel...
  • Page 284 5 - 142 Diagnosis 5.0/5.7/6.0/8.1L DTC 81 - Fuel Injector Driver A Circuit High, Low or Open Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check 1. Disconnect the appropriate harness connectors of the four fuel injectors.
  • Page 285 5.0/5.7/6.0/8.1L Diagnosis 5 - 143 This Page Was Intentionally Left Blank MEFI 4 - PCM...
  • Page 286 5 - 144 Diagnosis 5.0/5.7/6.0/8.1L Hot in Run And Start From S121 Fuse Block To ECM Term To Fuel Pump "J2-19"" INJ/ECM Fuse Relay Term. "86" S122 To Ignition Coil Connector (odd cyl.) Term. "H" PNK 439 To Ignition Coil Connector (even cyl.) S127 Term.
  • Page 287 5.0/5.7/6.0/8.1L Diagnosis 5 - 145 Hot in Run And Start From S121 Fuse Block To ECM Term To Fuel Pump "J2-19"" INJ/ECM Fuse Relay Term. "86" S122 To Ignition Module Connector Term. "A" PNK 439 To Ignition Coil Connector Term. "A" PNK 439 Fuel Fuel...
  • Page 288 5 - 146 Diagnosis 5.0/5.7/6.0/8.1L DTC 81 - Fuel Injector Driver B Circuit High, Low or Open Step Action Value Was the “On-Board Diagnostic” (OBD) system check Go to OBD performed? — Go to Step 2 System Check 1. Disconnect the appropriate harness connectors of the four fuel injectors.
  • Page 289 5.0/5.7/6.0/8.1L Diagnosis 5 - 147 MEFI 4 - PCM...
  • Page 290 5 - 148 Diagnosis 5.0/5.7/6.0/8.1L MEFI 4 - PCM...
  • Page 291 MP 5.0L MP 5.7L MP 6.0L (Horsepower) (275 HP) (330 HP) (375 HP) Displacement 5.0L (305 CID) 5.7L (350 CID) 6.0L (364 CID) Bore 3.75 in. (95.0 mm) 4.0 in. (101.6 mm) 4.0007 in. (101.618 mm) Stroke 3.48 in. (88.3 mm) 3.48 in.
  • Page 292 5 - 150 Diagnosis 5.0/5.7/6.0/8.1L PCM MASTER FUEL PRESSURE SPECIFICATIONS - 2005 MODEL MP 5.0L MP 5.7L MP 6.0L (Horsepower) (275 HP) (330 HP) (375 HP) MY ‘03 Only Fuel Pressure 57-62 psi @ WOT 57-62 psi @ WOT 57-60 psi @ WOT STD.
  • Page 293 MP 5.0L MP 5.7L MP 6.0L (Horsepower) (275 HP) (330 HP) (375 HP) Displacement 5.0L (305 CID) 5.7L (350 CID) 6.0L (364 CID) Bore 3.75 in. (95.0 mm) 4.0 in. (101.6 mm) 4.0007 in. (101.618 mm) Stroke 3.48 in. (88.3 mm) 3.48 in.
  • Page 294 5 - 152 Diagnosis 5.0/5.7/6.0/8.1L PCM MASTER FUEL PRESSURE SPECIFICATIONS - 2006 MODEL MP 5.0L MP 5.7L MP 6.0L (Horsepower) (275 HP) (330 HP) (375 HP) MY ‘03 Only Fuel Pressure 57-62 psi @ WOT 57-62 psi @ WOT 57-60 psi @ WOT STD.
  • Page 295 5.0/5.7/6.0/8.1L PCV System 6 - 1 Marine Electronic Fuel Injection (MEFI) Section 6 Positive Crankcase Ventilation (PCV) System Contents General Description ..........Page 1 Functional Check of Positive Crankcase Operation ............Page 1 Ventilation (PCV) System......... Page 2 Results of Incorrect Operation ......Page 1 On-Board Service ..........
  • Page 296 6 - 2 PCV System 5.0/5.7/6.0/8.1L Diagnosis If vacuum is present, the PCV system is functioning properly. No vacuum indicated, the engine may not be sealed and/or is drawing in outside air. Check valve cover Functional Check of Positive Crankcase gasket, oil pan gasket, etc.
  • Page 297 5.0/5.7/6.0L/8.1L Symptoms 7 - 1 Marine Electronic Fuel Injection (MEFI) Section 7 Symptoms Contents Symptoms ............. Page 2 Cuts Out, Misses ..........Page 14 Important Preliminary Checks ....... Page 2 Rough, Unstable Or Incorrect Idle, Stalling..Page 16 Visual/Physical Check ........... Page 2 Poor Fuel Economy ..........
  • Page 298 7 - 2 Symptoms 5.0/5.7/6.0/8.1L Symptoms • Improperly formed or damaged terminals and/or connectors. • All connector terminals in the problem circuit should be Important Preliminary Checks carefully checked for proper contact tension. Before Starting • Poor terminal to wire connection (crimping). This requires removing the terminal from the connector Before using this section you should have performed body to check.

  • Page 299: Symptoms

    5.0/5.7/6.0L/8.1L Symptoms 7 - 3 Hard Start Symptom Step Action Value Defi nition: Engine cranks OK, but does not start for a long time. Does eventually run, or may start but immediately dies. Was the “On-Board Diagnostic (OBD) System Check” Go to OBD performed? —...
  • Page 300 7 - 4 Symptoms 5.0/5.7/6.0/8.1L Hard Start Symptom Step Action Value 1. Check ECT sensor for being shifted in value. 2. With the engine completely cool, compare the ECT sensor temperature with an accurate reading of ambient air temperature. Are the temperatures within the specifi ed value of each other? -12°...
  • Page 301 5.0/5.7/6.0L/8.1L Symptoms 7 - 5 Hard Start Symptom Step Action Value 1. Review all diagnostic steps within this procedure. 2. If all steps have been completed and no malfunctions have been found, review/inspect the following: • Visual/physical inspection. • Scan tool data. •...

  • Page 302: Surges And/Or Chuggles

    7 - 6 Symptoms 5.0/5.7/6.0/8.1L Surges and/or Chuggles Symptom Step Action Value Defi nition: Engine power variation under steady throttle or cruise. Feels like the vehicle speeds up and slows down with no change in the accelerator pedal. Was the “On-Board Diagnostic (OBD) System Check” Go to OBD performed? —...
  • Page 303 5.0/5.7/6.0L/8.1L Symptoms 7 - 7 Surges and/or Chuggles Symptom Step Action Value 1. Remove spark plugs and check for wet plugs, cracks, wear, improper gap, burned electrodes or heavy deposits. • Refer to Distributor Ignition System. Notice: If spark plugs are gas or oil fouled, the cause of the fouling must be determined before replacing the spark plugs.

  • Page 304: Lack Of Power, Sluggish Or Spongy

    7 - 8 Symptoms 5.0/5.7/6.0/8.1L Lack of Power, Sluggish or Spongy Symptom Step Action Value Defi nition: Engine delivers less than expected power. Little or no increase in speed when accelerator pedal is pushed down part way. Was the “On-Board Diagnostic (OBD) System Check” Go to OBD performed? —...
  • Page 305 5.0/5.7/6.0L/8.1L Symptoms 7 - 9 Lack of Power, Sluggish or Spongy Symptom Step Action Value 1. Check ignition coil for cracks or carbon tracking. 2. If a problem is found, repair as necessary. Go to OBD Was a problem found? —...

  • Page 306: Detonation/Spark Knock

    7 - 10 Symptoms 5.0/5.7/6.0/8.1L Detonation/Spark Knock Symptom Step Action Value Defi nition: A mild to severe ping, usually worse under acceleration. The engine makes sharp metallic knocks that change with throttle opening. Was the “On-Board Diagnostic (OBD) System Check” Go to OBD performed? —...
  • Page 307 5.0/5.7/6.0L/8.1L Symptoms 7 - 11 Detonation/Spark Knock Symptom Step Action Value 1. Check for ECT sensor being shifted in value. 2. Check for proper output voltage of the TP sensor at closed throttle and wide open throttle. Also check throttle linkage for sticking, binding or worn. 2.

  • Page 308: Hesitation, Sag, Stumble

    7 - 12 Symptoms 5.0/5.7/6.0/8.1L Hesitation, Sag, Stumble Symptom Step Action Value Defi nition: Momentary lack of response as the accelerator is pushed down. Can occur at all vehicle speeds. Usually most severe when fi rst trying to make the vehicle move, as from a stop. May cause engine to stall if severe enough.
  • Page 309 5.0/5.7/6.0L/8.1L Symptoms 7 - 13 Hesitation, Sag, Stumble Symptom Step Action Value 1. Check for the ECT sensor shifted in value. 2. Check for intermittent opens or short to grounds in the ECT sensor, MAP sensor and TP sensor circuits. Also check for throttle linkage sticking, binding or worn.

  • Page 310: Cuts Out, Misses

    7 - 14 Symptoms 5.0/5.7/6.0/8.1L Cuts Out, Misses Symptom Step Action Value Defi nition: Steady pulsation or jerking that follows engine speed, usually more pronounced as engine load increases. The exhaust has a steady spitting sound at idle, low speed or on hard acceleration for fuel starvation that can cause engine to cut out.
  • Page 311 5.0/5.7/6.0L/8.1L Symptoms 7 - 15 Cuts Out, Misses Symptom Step Action Value 1. Check engine mechanical for the following conditions. • Low compression. • Sticking or leaking valves. • Bent push rods. • Worn rocker arms. • Broken valve springs. •...

  • Page 312: Rough, Unstable Or Incorrect Idle, Stalling

    7 - 16 Symptoms 5.0/5.7/6.0/8.1L Rough, Unstable or Incorrect Idle, Stalling Symptom Step Action Value Defi nition: Engine runs unevenly at idle. If severe, the engine or vehicle may shake. Engine idle speed varies in RPM. Either condition may be severe enough to stall the engine. Was the “On-Board Diagnostic (OBD) System Check”...
  • Page 313 5.0/5.7/6.0L/8.1L Symptoms 7 - 17 Rough, Unstable or Incorrect Idle, Stalling Symptom Step Action Value 1. Check fuel injectors. • Refer to Injector Coil Test and Injector Balance Test at the end of this section. 2. If a problem is found, repair as necessary. Go to OBD Was a problem found? —...
  • Page 314 7 - 18 Symptoms 5.0/5.7/6.0/8.1L Rough, Unstable, or Incorrect Idle, Stalling Symptom Step Action Value 1. Check for faulty motor mounts. 2. If a problem is found, repair as necessary. Go to OBD Was a problem found? — System Check Go to Step 21 1.
  • Page 315 5.0/5.7/6.0L/8.1L Symptoms 7 - 19 Poor Fuel Economy Symptom Step Action Value Defi nition: Fuel economy, as measured at selected intervals, is noticeably lower than expected. Also, economy is noticeably lower than it was on this vehicle at one time, as previously shown by documentation. Was the “On-Board Diagnostic (OBD) System Check”...
  • Page 316 7 - 20 Symptoms 5.0/5.7/6.0/8.1L Poor Fuel Economy Symptom Step Action Value 1. Check exhaust system for possible restriction. 2. Inspect exhaust system for damaged or collapsed pipes. 3. If a problem is found, repair as necessary. Go to OBD Was a problem found? —...
  • Page 317 5.0/5.7/6.0L/8.1L Symptoms 7 - 21 Dieseling, Run-On Symptom Step Action Value Defi nition: Engine continues to run after key is turned “OFF,” but runs very rough. If engine runs smooth, check ignition switch and adjustment. Was the “On-Board Diagnostic (OBD) System Check” Go to OBD performed? —...
  • Page 318 7 - 22 Symptoms 5.0/5.7/6.0/8.1L Backfi re Symptom Step Action Value Defi nition: Fuel ignites in the intake manifold, or in the exhaust system, making loud popping noise. Was the “On-Board Diagnostic (OBD) System Check” Go to OBD performed? — Go to Step 2 System Check Was visual/physical check performed?
  • Page 319 5.0/5.7/6.0L/8.1L Symptoms 7 - 23 Backfi re Symptom Step Action Value Check for intermittent open or short to ground in the ignition circuit to the system relay. Go to OBD Was a problem found? — System Check Go to Step 13 1.
  • Page 320 7 - 24 Symptoms 5.0/5.7/6.0/8.1L ECM Connector “J1” Wire Component DTC(s) Possible Symptoms Pin Function Color Connector Affected From Faulty Circuit J1-01 Knock Sensor 2 lt blu/blu Knock Poor Fuel Economy, Signal (6.0/8.1L Only) Sensor 2 Poor Performance J1-02 Diagnostic “Test” blk/wht Data Link None...
  • Page 321 5.0/5.7/6.0L/8.1L Symptoms 7 - 25 ECM Connector “J1” Wire Component DTC(s) Possible Symptoms Pin Function Color Connector Affected From Faulty Circuit J1-29 ECM Ground Engine Block None An open ground or high resistance ground may cause any or all symptoms. J1-30 Knock Sensor 1 dk blu...
  • Page 322 7 - 26 Symptoms 5.0/5.7/6.0/8.1L ECM Connector “J2” Component Pin Function Wire Connector DTC(s) Possible Symptoms Color Cavity Affected From Faulty Circuit J2-01 Battery Feed Splice None No Start J2-02 5 Volt MAP/IAT, TP 22, 25, 34 Lack of Power, Surge, Rough Reference Sensors Idle, Exhaust Odor...
  • Page 323 5.0/5.7/6.0L/8.1L Symptoms 7 - 27 ECM Connector “J2” Wire Component DTC(s) Possible Symptoms Pin Function Color Connector Affected From Faulty Circuit J2-30 Ignition Control C 2127 Ignition Coil Poor Performance, Poor Fuel Inline Connector (cyl. #7) Fuel Economy, engine misfi re J2-31 Ignition Control A 2121...

  • Page 324: Fuel Injector Coil Test

    7 - 28 Symptoms 5.0/5.7/6.0/8.1L INJECTOR SWITCH BOX J39021-210 FUEL INJECTOR TESTER Ω LOW VEHICLE BATTERY DIGITAL VOLT READY TO TEST V-DC TEST IN PROGRESS V-AC METER AMPERAGE SUPPLY SELECTOR SWITCH (DVOM) Coil Test Balance Test 4 amp 4 amp 2.5 amp 0.5-2.5 0.5 amp...
  • Page 325 5.0/5.7/6.0L/8.1L Symptoms 7 - 29 Fuel Injector Coil Test Step Action Value Was the “On-Board Diagnostic (OBD) System Check” Go to OBD performed? — Go to Step 2 System Check 1. Turn the engine “OFF.” 2. Relieve the fuel pressure. •...

  • Page 326: Fuel Injector Balance Test

    7 - 30 Symptoms 5.0/5.7/6.0/8.1L (INITIAL PRESSURE) READING FUEL PRESSURE GAUGE FUEL INJECTOR TESTER LOW VEHICLE BATTERY READY TO TEST TEST IN PROGRESS AMPERAGE SUPPLY SELECTOR SWITCH Coil Test Balance Test 4 amp 4 amp 2.5 amp 0.5-2.5 0.5 amp INJECTOR READING CONNECTOR...
  • Page 327 5.0/5.7/6.0L/8.1L Symptoms 7 - 31 6. Allow the fuel pressure to stabilize about 3 minutes. Test Description On a hot engine, fuel pressure may increase due to Caution: Wrap a shop towel around the fuel pressure fuel expansion after the pump stops running. This is a connection in order to reduce the risk of fire and normal condition, but the fuel pressure should stabilize personal injury.
  • Page 328 7 - 32 Symptoms 5.0/5.7/6.0/8.1L Fuel Injector Balance Test Step Action Value 1. Turn the ignition “OFF.” 2. Connect the J 39021 Fuel Injector Tester, the J39021-303 Injector Harness Connector (if needed) and the J 39021-210 Injector Switch Box to a fuel injector.
  • Page 329 5.0/5.7/6.0L/8.1L Symptoms 7 - 33 Fuel Injector Balance Test Step Action Value 1. Turn ignition “OFF.” 2. Remove test equipment. 3. Re-connect all harnesses and fuel lines. 4. Install a scan tool. 5. Ignition “ON,” engine “OFF.” 6. Check for fuel leaks. 7.
  • Page 330 7 - 34 Symptoms 5.0/5.7/6.0/8.1L This page left intentionally blank MEFI 4 - PCM...
  • Page 331 5.0/5.7/6.0/8.1L Master Specifi cations 8 - 1 MEFI 4 - PCM...
  • Page 332 8 - 2 Master Specifi cations 5.0/5.7/6.0/8.1L MEFI 4 - PCM...
  • Page 333 MP 5.0L MP 5.7L MP 6.0L (Horsepower) (275 HP) (330 HP) (375 HP) Displacement 5.0L (305 CID) 5.7L (350 CID) 6.0L (364 CID) Bore 3.75 in. (95.0 mm) 4.0 in. (101.6 mm) 4.0007 in. (101.618 mm) Stroke 3.48 in. (88.3 mm) 3.48 in.
  • Page 334 8 - 4 Master Specifi cations 5.0/5.7/6.0/8.1L PCM MASTER FUEL PRESSURE SPECIFICATIONS - 2005 MODEL MP 5.0L MP 5.7L MP 6.0L (Horsepower) (275 HP) (330 HP) (375 HP) MY ‘03 Only Fuel Pressure 57-62 psi @ WOT 57-62 psi @ WOT 57-60 psi @ WOT STD.
  • Page 335 MP 5.0L MP 5.7L MP 6.0L (Horsepower) (275 HP) (330 HP) (375 HP) Displacement 5.0L (305 CID) 5.7L (350 CID) 6.0L (364 CID) Bore 3.75 in. (95.0 mm) 4.0 in. (101.6 mm) 4.0007 in. (101.618 mm) Stroke 3.48 in. (88.3 mm) 3.48 in.
  • Page 336 8 - 6 Master Specifi cations 5.0/5.7/6.0/8.1L PCM MASTER FUEL PRESSURE SPECIFICATIONS - 2006 MODEL MP 5.0L MP 5.7L MP 6.0L (Horsepower) (275 HP) (330 HP) (375 HP) MY ‘03 Only Fuel Pressure 57-62 psi @ WOT 57-62 psi @ WOT 57-60 psi @ WOT STD.
  • Page 337 5.0/5.7/6.0/8.1L Master Specifi cations 8 - 7 This page left intentionally blank MEFI 4 - PCM...

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