Suzuki XL7 2007 Service Manual page 226

1A-121 Engine General Information and Diagnosis:
Typical Scan Tool Data
FTP Sensor
Circuit
Operating Conditions: Engine operating in Closed Loop at idle
Parameter Normal Range: 0.2-4.8 V
5-Volt Reference
FTP Sensor Signal
Low Reference
Circuit/System Description
The evaporative emission (EVAP) system is used to
store fuel vapors in order to reduce the amount of fuel
vapors into the atmosphere. The fuel tank pressure
(FTP) sensor is only used for EVAP system diagnostics.
The FTP sensor is a transducer that varies resistance
according to changes in the fuel tank pressure. The
engine control module (ECM) monitors the FTP sensor
signal in order to detect vacuum decay and excess
vacuum during the EVAP system diagnostic test. The
ECM supplies a 5-volt reference and a low reference
circuit to the FTP sensor.
FTP Sensor Signal
Voltage
High, Approximately 1.5
Volts or More
Low, Approximately 1.5
Volts or Less
Conditions for Running the DTC
• The engine is operating.
• The vehicle speed is 0 mph.
• The BARO is greater than 68 kPa.
• The ambient air temperature is greater than −7°C
(19°F).
• The fuel level is between 12-88 percent.
• The DTCs run continuously once the above conditions
are met for 14 seconds.
Conditions for Setting the DTC
P0452
The ECM detects the FTP sensor signal voltage is less
than 0.13 volt for 4 seconds or for a cumulative of 50
seconds.
P0453
The ECM detects the FTP sensor signal voltage is more
than 4.8 volts for 4 seconds or for a cumulative of 50
seconds.
Action Taken When the DTC Sets
DTC P0452 and P0453 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTC P0452 and P0453 are Type B DTCs.
Short to Ground
0 V
0 V
Fuel Tank Pressure
Negative Pressure/
Vacuum
Positive Pressure
Open
0 V
0 V
— 4.2 V
Diagnostic Aids
If a shared 5-volt reference circuit is shorted to ground or
shorted to a voltage, other 5-volt reference circuits may
be affected.
Reference Information
Schematic Reference
"Engine Controls Schematics"
Connector End View Reference
• "Engine Control Module Connector End Views"
• "Engine Controls Connector End Views"
Description and Operation
"Fuel System Description: "
Electrical Information Reference
• "Circuit Testing: "
• "Connector Repairs: "
• "Testing for Intermittent Conditions and Poor
Connections: "
• "Wiring Repairs: "
DTC Type Reference
"Powertrain Diagnostic Trouble Code (DTC) Type
Definitions"
Scan Tool Reference
• "Scan Tool Data List - Engine Controls - 3.6L (LY7)"
• "Scan Tool Data Definitions - Engine Controls - 3.6L
(LY7)"
• "Scan Tool Output Controls - Engine Controls - 3.6L
(LY7)"
Circuit/System Verification
1. Ignition ON, observe the DTC information with a
scan tool. DTC P0642 or P0643 should not be set.
➢ If a DTC is set, refer to "DTC P0642 or P0643".
2. Observe the FTP Sensor voltage parameter. The
FTP sensor voltage should be between 0.1-4 volts.
3. If the vehicle passes the Circuit/System Verification
test, then operate the vehicle within the conditions
for running the DTC. You may also operate the
vehicle within the conditions that are captured in the
Freeze Frame/Failure Records List.
Short to Voltage
5 V
5 V
—