P000F

P000F-FUEL SYSTEM OVER PRESSURE RELIEF VALVE ACTIVATED





For complete wiring diagrams refer to Diagrams/Electrical.


Theory of Operation

The ECM will turn on the MIL lamp immediately after this diagnostic runs and fails. The ECM will turn off the MIL lamp after the diagnostic runs and passes in 4 consecutive drive cycles.

- When Monitored:

Engine running

- Set Condition:

Fuel pressure deviation from setpoint occurs at a rate higher than a calibrated amount.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test


1. PRESSURE LIMITING VALVE

Ignition on, engine not running.

Using the electronic scan tool, view the pressure limiting valve counter and pressure limiting valve timer.

Is the counter value higher than 50 or the timer value higher than 5 hours?

Yes

- Change the pressure limiting valve. When valve replacement is complete, use the scan tool to reset the pressure limiting valve counter and timer. This command is in the PCM Misc Functions.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 2

2. PRESSURE LIMITING VALVE

Turn the ignition off.

Remove the banjo bolt from the pressure limiting valve drain on the fuel rail.

Install fuel system test fitting #9012 into the drain.

Attach one end of a fuel hose to the fuel fitting and put the other end of the fuel hose into a container.

Operate the engine at idle and watch for fuel flow into the container.

Operate the engine at idle and actuate the high pressure safety valve test with the scan tool.

Watch for fuel flow into the fuel container.

Does fuel flow into the container under either operating conditions?

Yes

- Change the pressure limiting valve. When valve replacement is complete, use the scan tool to reset the pressure limiting valve counter and timer. This command is in the PCM Misc Functions.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 3

3. LIFT PUMP

Perform In-Tank Fuel Lift Pump Flow/Diagnostic Test Procedure. In-Tank Fuel Lift Pump Flow/Diagnostic Test Procedure

Does the lift pump pass the In-Tank Fuel Lift Pump Flow/Diagnostic Test Procedure ?

Yes

- Go To 4

No

- Replace Lift Pump
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

4. HIGH PRESSURE PUMP PERFORMANCE

Perform High Pressure Fuel Pump Performance Test. High Pressure Fuel Pump Performance Test

Is the fuel flow above the specification?

Yes

- Go To 5

No

- Replace appropriate component as per High Pressure Fuel Pump Performance Test tree.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

5. HIGH PRESSURE PUMP RETURN

Perform Fuel Pump Return Flow Test. Fuel Pump Return Flow Test


NOTE: Part of this test requires that the Pressure Limiting Valve leakage is checked. This work was already performed in step 2.

Is the drain flow measured less than 1000 ml/minute at idle?

Yes

- Go To 6

No

- Replace fuel injection pump
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

6. FUEL INJECTOR RETURN FLOW

Perform Injector Return Flow Test. Injector Return Flow Test


NOTE: Step 6 requires Fuel Injector Return Flow to be measured. That test can be performed at the same time as the High Pressure Pump Return test.

Is the fuel flow below the specification?

Yes

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition

No

- Replace appropriate component per Injector Return Flow test.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test