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 provide 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 ignition is ON or the engine is operating.
* The DTCs run continuously once the above condition is met.

Conditions for Setting the DTC

P0452

The ECM detects the FTP sensor voltage is less than 0.2 volt.

P0453

The ECM detects the FTP sensor voltage is greater than 4.8 volts.

Action Taken When the DTC Sets

DTC P0452 and P0453 are Type B DTCs.

Conditions for Clearing the 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.
* The scan tool 5 volt reference parameter should display between 4.8-5.2 volts.

Circuit/System Verification

1. Ignition ON, observe the DTC information with a scan tool. Verify DTC P0651 is not set.

• If DTC P0651 is set, Refer to DTC P0641 or P0651. P0641 P0651

2. Ignition ON, observe the FTP Sensor voltage parameter. The FTP sensor voltage should be between 0.2-4.0 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, disconnect the harness connector of the FTP sensor.
2. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit and ground.

• If greater than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit/connections test normal, replace the ECM.

Important: The 5-volt reference circuits are internally and externally connected at the ECM. Other component DTCs may be set. If other DTCs are set, review the electrical schematic and diagnose the applicable circuits and components.

3. Test for 4.8-5.2 volts between the 5-volt reference circuit and ground.

• If less than 4.8 volts, 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 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.

4. Ignition ON, verify that the FTP Sensor parameter is less than 4.8 volts

• If greater than 4.8 volts, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.

5. Ignition ON, install a 3A fused jumper wire between the signal circuit and the 5-volt reference circuit. Verify that the FTP Sensor parameter is greater than 4.8 volts.

• If less than 4.8 volts, test the signal circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the ECM.

6. If all circuits/connections test normal, replace the FTP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Fuel Tank Pressure Sensor Replacement
* Programming and Relearning for ECM setup, and programming Programming and Relearning