Chrysler Dodge Caravan 2002 Manual page 349

8E - 12 ELECTRONIC CONTROL MODULES
POWERTRAIN CONTROL MODULE (Continued)
• Ignition sense
• Intake Air Temperature Sensor
• Knock Sensor
• Leak Detection Pump Feedback
• Manifold Absolute Pressure (MAP) Sensor
• Park/Neutral (from transmission control module)
• PCI Bus
• Power Steering Pressure Switch
• Proportional Purge Sense
• SCI Receive
• Speed Control
• Throttle Position Sensor
• Torque Management Input (From TCM)
• Transaxle Control Module (TCM)
• Transaxle Gear Engagement (From TCM)
• Vehicle Speed (from transmission control mod-
ule)
NOTE: PCM Outputs:
• Air Conditioning Clutch Relay
• Automatic Shut Down (ASD) and Fuel Pump
Relays
• Data Link Connector (PCI and SCI Transmit)
• Double Start Override
• EGR Solenoid
• Fuel Injectors
• Generator Field
• High Speed Fan Relay
• Idle Air Control Motor
• Ignition Coils
• Leak Detection Pump
• Low Speed Fan Relay
• MTV Actuator
• Proportional Purge Solenoid
• SRV Valve
• Speed Control Relay
• Speed Control Vent Relay
• Speed Control Vacuum Relay
• 8 Volt Output
• 5 Volt Output
Based on inputs it receives, the powertrain control
module (PCM) adjusts fuel injector pulse width, idle
speed, ignition timing, and canister purge operation.
The PCM regulates the cooling fans, air conditioning
and speed control systems. The PCM changes gener-
ator charge rate by adjusting the generator field.
The PCM adjusts injector pulse width (air-fuel
ratio) based on the following inputs.
• Battery Voltage
• Intake Air Temperature Sensor
• Engine Coolant Temperature
• Engine Speed (crankshaft position sensor)
• Exhaust Gas Oxygen Content (heated oxygen
sensors)
• Manifold Absolute Pressure
• Throttle Position
The PCM adjusts engine idle speed through the
idle air control motor based on the following inputs.
• Brake Switch
• Engine Coolant Temperature
• Engine Speed (crankshaft position sensor)
• Park/Neutral (transmission gear selection)
• Transaxle Gear Engagement
• Throttle Position
• Vehicle Speed (from Transmission Control Mod-
ule)
The PCM adjusts ignition timing based on the fol-
lowing inputs.
• Intake Air Temperature
• Engine Coolant Temperature
• Engine Speed (crankshaft position sensor)
• Knock Sensor
• Manifold Absolute Pressure
• Park/Neutral (transmission gear selection)
• Transaxle Gear Engagement
• Throttle Position
The automatic shut down (ASD) and fuel pump
relays are mounted externally, but turned on and off
by the powertrain control module through the same
circuit.
The camshaft and crankshaft signals are sent to
the powertrain control module. If the PCM does not
receive both signals within approximately one second
of engine cranking, it deactivates the ASD and fuel
pump relays. When these relays are deactivated,
power is shut off to the fuel injectors, ignition coils,
fuel pump and the heating element in each oxygen
sensor.
The PCM contains a voltage converter that
changes battery voltage to a regulated 8.0 volts. The
8.0 volts power the camshaft position sensor, crank-
shaft position sensor and vehicle speed sensor. The
PCM also provides a 5.0 volts supply for the engine
coolant temperature sensor, intake air temperature
sensor, manifold absolute pressure sensor and throt-
tle position sensor.
The PCM engine control strategy prevents reduced
idle speeds until after the engine operates for 320 km
(200 miles). If the PCM is replaced after 320 km (200
miles) of usage, update the mileage in new PCM. Use
the DRB scan tool to change the mileage in the PCM.
Refer to the appropriate Powertrain Diagnostic Man-
ual and the DRB scan tool.
RS