Fault-Tracing
Troubleshooting ECM-P008900
Checking fuel pressure sensor
Note! If diagnostic trouble codes (DTC) for the fuel pressure sensor or atmospheric pressure sensor are stored, these diagnostic trouble codes (DTC) must be fault-traced and remedied first.
Hint: The following method is for checking if the diagnostic trouble code has been caused by a defective fuel pressure sensor. This can be done by comparing if the fuel pressure sensor's signal (readout in the diagnostic tool) is unstable when actual fuel pressure (readout on pressure gauge connected to fuel system's lines) is stable.
- Connect pressure gauge: Fuel pressure gauge Fuel Pressure Gauge
Caution! The pressure in the fuel injection system can reach approximately 650 kPa when this diagnostic trouble code (DTC) is stored. Use an adapted manometer.
- Run the engine until it is warm and let it idle.
- A/C off.
Read off relative fuel pressure.
The relative fuel pressure is calculated from the fuel pressure sensor's and the atmospheric pressure sensor's signal (=absolute pressure minus atmospheric pressure).
Check the value on the pressure gauge and the readout value in the diagnostic tool. If the fuel pressure sensor's readout signal is unstable when the actual fuel pressure (readout on pressure gauge connected to fuel system's lines) is stable, this indicates that there is a malfunction in the circuit for the fuel pressure sensor.
Is the fuel pressure sensor OK?
Yes - Checking components
No - Checking components and wiring
-------------------------------------------------
Checking components
Check that the fuel level in the tank is not too low (almost no fuel).
Check the connectors between fuel pump module and the fuel pump for contact resistance and oxidation.
Check fuel lines and fuel filter for clogging and leakage.
Try with a new fuel pump if no malfunction is found in the above troubleshooting.
Hint: The diagnostic trouble code may also have been generated by a defective fuel pump module.
Remedy as necessary.
Other information
- For replacing fuel pump: Level sensor, fuel tank, right-hand/fuel tank, replacing Level Sensor, Fuel Tank, Right-Hand/Fuel Tank, Replacing
- Fuel pump driver module Service and Repair
- Checking wiring and terminals Checking Wiring and Terminals
Continue - Verification
-------------------------------------------------
Checking components and wiring
Check the fuel pressure sensor's connector for contact resistance and oxidation.
Try with a new fuel pressure sensor if no malfunction is found in the above troubleshooting.
Remedy as necessary.
Other information
- Connecting the breakout box, B8444S Connecting the Breakout Box
- Signal specification, engine control module (ECM), B8444S Signal Specification
- Fuel pressure and temperature sensor, replacing, B8444S, B6324S Service and Repair
- Checking wiring and terminals Checking Wiring and Terminals
Continue - Verification
-------------------------------------------------
Verification
Verification
Hint: After carrying out the repair, check that the fault has been remedied.
Caution! The pressure in the fuel injection system can reach approximately 650 kPa when this diagnostic trouble code (DTC) is stored. Use an adapted manometer.
- Connect pressure gauge: Fuel pressure gauge Fuel Pressure Gauge
- Run the engine until it is warm and let it idle.
- A/C off.
Read off relative fuel pressure.
The relative fuel pressure is calculated from the fuel pressure sensor's and the atmospheric pressure sensor's signal (=absolute pressure minus atmospheric pressure).
Check that the value on the pressure gauge and the readout value are the same. Different values indicate malfunction.
Is the function OK?
Yes - Troubleshooting procedure complete
No - Fault-tracing information
-------------------------------------------------
Fault-tracing information
Information
Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.
Do you want to exit fault-tracing?
Yes - Exit Fault-tracing
No - Attempt New Test
------------------------
Attempt New Test - Checking fuel pressure sensor
-------------------------------------------------