P0452
DTC P0452 or P0453
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P0452
- Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage
DTC P0453
- Fuel Tank Pressure (FTP) Sensor Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
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.
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.
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.
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. P0642 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.
Circuit/System Testing
1. Ignition OFF, remove the fuse that supplies B+ to terminal C2-56 of the ECM.
2. Disconnect the C-420 harness connector at the rear of the fuel tank.
3. Test for less than 5.0 ohms of resistance between the low reference circuit terminal E and ground, at the ECM side of the connector.
^ If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit/connections test normal, replace the ECM.
4. Install the fuse that supplies B+ to terminal C2-56 of the ECM.
5. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground, at the ECM side of connector C-420.
^ If less than the specified range, test the 5-volt reference circuit for a short to ground or open/high resistance. If the circuit/connections test normal, replace the ECM.
^ If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.
6. Verify that the FTP Sensor parameter is less than 4.8 volts
^ If greater than the specified value, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.
7. At the ECM side of C-420, install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C. Verify that the FTP Sensor parameter is greater than 4.8 volts.
^ If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the ECM.
8. Remove the fuel tank.
9. Disconnect the FTP sensor connector.
10. Inspect the FTP sensor circuits in the fuel tank harness, between the FTP sensor connector and C-420 for the following conditions, and repair as necessary:
* Damaged wiring or terminals
* Open circuits
* Short to ground
* Wire to wire short
11. If all circuits/connections test normal, test or replace the FTP sensor.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
* Fuel Tank Pressure Sensor Replacement
* Refer to Programming and Relearning. Programming and Relearning