Signal Too High/Signal Too Low/Signal Missing

Signal too high/Signal too low/Signal missing

Checking the status




- Start the engine and run it to normal operating temperature.
Read off the fuel pump (FP) load.
Check whether the fault is permanent or intermittent by checking the value of the fuel pump (FP) load (signal from the engine control module (ECM) to the fuel pump (FP) control module).
Check that the signal is approximately 35 % (±5 %) with the engine idling at operating temperature.
The fault is permanent if the signal is incorrect or the engine will not start.
The fault is intermittent if the signal is correct.










Continue - Checking the component and wiring

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Checking the component and wiring
Check the connector for the fuel pump (FP) control module. Check for contact resistance. Check for oxidation.
Check the cable between the Engine control module (ECM) terminal #B20 (#C20) and fuel pump control module terminal #1. Check for an open-circuit, short-circuit to ground and short-circuit to voltage.
Remedy as necessary.

Hint: The diagnostic trouble code (DTC) can be caused by a defective fuel pump (FP) control module.

Other information:
- Connecting the breakout box Connecting The Breakout Box, Engine Control Module (ECM)
- Signal specification Signal Specification, Engine Control Module (ECM)
- Fuel pump driver module Service and Repair
- Checking wiring and terminals Checking Wiring and Terminals














Continue - Verification

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Verification




Verification

Verification

Hint: After carrying out the repair, check that the fault has been remedied.




- Reinstall the connectors, components etc.
- Start the engine and run it to normal operating temperature.
Read off the fuel pump (FP) load.
Check that the engine starts and that the signal is approximately 35 % (±5 %) when the engine is idling at operating temperature.





Is the function correct?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFIED - Fault Found

VERIFICATION FAILED - Fault-tracing information

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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

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Attempt New Test - Checking the status

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