Signal Too Low

Signal too low

Checking the status




- Start the engine and run it to normal operating temperature.
Check whether the fault is permanent or intermittent by reading off the signal from the fuel pressure sensor. With the engine at operating temperature and idling, the signal must be approximately 400 kPa.
The fault is permanent if the signal is incorrect. 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 signal cable. Check for a short-circuit to ground.
Take readings between:
- Engine Control Module (ECM) #A89 (#B29) and fuel pressure sensor #4.
Remedy as necessary.

Other information
- Connecting the breakout box, B5254T7 Connecting the Breakout Box, Engine Control Module (ECM)
- Signal specification, B5254T7 Signal Specification
- Pressure sensor, fuel rail (FRP), B5254T7 Service and Repair
- Checking wiring and terminals Checking Wiring and Terminals













Continue - Verification

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Verification




Verification

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








- Ignition off
- Reconnect the connectors, reinstall components etc.
- Start the engine and run it to normal operating temperature.
Read off the fuel pressure sensor signal. Check that the fuel pressure is approximately 400 kPa with the engine idling at operating temperature.





Is the value correct?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFICATION FAILED - Fault-tracing information

VERIFIED - FAULT FOUND

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Fault-tracing information

Attempt New Test - Checking the status

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