P0454
DTC P0451 or P0454
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provide an overview of each diagnostic category.
DTC Descriptors
DTC P0451 00
- Fuel Tank Pressure Sensor Performance
DTC P0454 00
- Fuel Tank Pressure Sensor Circuit Intermittent
Diagnostic Fault Information
Circuit/System Description
The evaporative emission (EVAP) system stores fuel vapors in order to reduce the amount of fuel vapors into the atmosphere. The fuel tank pressure sensor is used for EVAP system diagnostics. The fuel tank pressure sensor is a transducer that varies resistance according to changes in fuel tank pressure. The engine control module (ECM) monitors the fuel tank pressure sensor signal in order to detect vacuum decay and excess vacuum during the EVAP system diagnostic tests.
Conditions for Running the DTC
P0451 00
* This diagnostic runs when the engine off natural vacuum small leak test, DTC P0442 00, is in progress.
* This diagnostic can be tested 2 times during the engine off period.
P0454 00
* This diagnostic runs when the engine off natural vacuum small leak test, DTC P0442 00, is in progress.
* This diagnostic can be tested 1 time during the engine off period.
* The ECM does not detect a refueling event.
Conditions for Setting the DTC
P0451 00
DTC P0451 00 will set if the controller is unable to re-zero the fuel tank pressure sensor voltage within a calibrated range. The length of the test can be up to 10 min.
P0454 00
The ECM detects an abrupt change in the fuel tank pressure sensor voltage, other than a refueling event. The length of the test can be up to 10 min.
Action Taken When the DTC Sets
DTCs P0451 00 and P0454 00 are Type A DTCs
Conditions for Clearing the DTC
DTCs P0451 00 and P0454 00 are Type A DTCs
Diagnostic Aids
* A restriction in the EVAP canister or vent lines could prevent fuel vapor pressure from decreasing fast enough. If the pressure does not decrease fast enough, the re-zero procedure may not complete successfully, which could cause DTC P0451 00 to set.
* Verify that the reference port on the fuel tank pressure sensor is not restricted.
* A resistance in the circuits of the fuel tank pressure sensor may cause DTC P0451 00 to set.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Evaporative Emission Control System Description (Evaporative Emission Control System Description)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Special Tools
* J 4143-200 - Evaporative Emissions System Tester
* GE 41415-50 - Fuel Tank Cap Adapter
* J 4143-300 - EVAP Cap And Plug Kit
For equivalent regional tools, refer to Special Tools (Tools and Equipment).
Circuit/System Verification
1. If DTC P0454 00 is set Inspect for an intermittent and for a poor connection at the B150 Fuel Tank Pressure Sensor and the K20 Engine Control Module.
2. Engine idling, command the EVAP Vent Solenoid ON and OFF with a scan tool while observing the following control circuit status parameters:
* EVAP Vent Sol Short Ground Test Status
* EVAP Vent Sol Open Test Status
* EVAP Vent Sol Short Volts Test Status
• Each parameter should display OK or Not Run.
3. Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the Q13 Evaporative Emission Vent Solenoid Valve.
2. Remove the fuel fill cap. Connect the GE 41415-50 - fuel tank cap adapter to the fuel tank filler neck.
3. Connect the J 4143-200 - evaporative emissions system tester to the GE 41415-50 - fuel tank cap adapter.
4. Pressurize the EVAP system with nitrogen to 1 kPa (0.14 PSI). Compare the Fuel Tank Pressure Sensor parameter with a scan tool to the J 4143-200 - evaporative emissions system tester pressure/vacuum gauge. The scan tool fuel tank pressure sensor parameter should be within 1 kPa (0.14 PSI) of the pressure/vacuum gauge.
• If not within the specified range, replace the B150 Fuel Tank Pressure Sensor.
5. Command the EVAP purge solenoid valve OPEN with a scan tool. Verify the scan tool Fuel Tank Pressure Sensor parameter decreases quickly to 0 kPa (0 PSI).
• If the pressure does not decrease quickly, inspect the EVAP vent system for a restriction. If the EVAP vent system tests normal replace the B150 Fuel Tank Pressure Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning)for ECM replacement, setup, and programming