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 components and wiring

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Checking components and wiring
Check the pump control module connector. Check for contact resistance and oxidation.
Check the cable between Engine Control Module (ECM) terminal #B47 (#B57) and pump control module terminal #1. Check for an open circuit, short circuit to ground and supply voltage.
Remedy as necessary.

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

Other information:
- Checking wiring and terminals Checking Wiring And Terminals
- To connect the breakout box, see Connecting the breakout box, B5254T2 Connecting the Test Box
- For information about signals, see Signal specification Signal Specification
- Control module fuel pump (FP), replacing, B5254T2 Service and Repair













Continue - Verification

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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 - Verification completed

No - 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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