Signal Too High/Signal Too Low/Signal Missing/Faulty Signal

Signal too high / Signal missing / Faulty signal

Checking the components and wiring

Caution! Do not apply rust solvent spray or grease to the heated oxygen sensor (HO2S) connector.

Check the heated oxygen sensor (HO2S) connector. Check for contact resistance and oxidation.
Check the cable between engine control module (ECM) terminal #A28 (#A28) and heated oxygen sensor (HO2S) terminal #2. Check for an open-circuit.

Note! If possible, measure from the rear of the affected connectors in order to minimize any damage and future loose connections.

Try a new heated oxygen sensor (HO2S) if the above fault-tracing does not remedy the fault.
Remedy as necessary.

Other information
- Connecting the breakout box, B5244T5, B5254T2 Connecting the Breakout Box
- For information about signals on 5 cylinder engines, see Signal specification Signal Description / Specification
- For information about signals on 6 cylinder engines, see Signal specification Signal Description / Specification
- Heated oxygen sensor (HO2S), replacing Heated Oxygen Sensor (HO2S), Replacing
- 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.








- Ignition off
- Reconnect the connectors, reinstall components etc.
- Test drive the car at an even speed (engine speed (RPM) above 2000 rpm) for at least 5 minutes
- Release the accelerator pedal (AP) quickly at least three times to simulate fuel shut-off
- Connect VCT2000 to the data link connector (DLC) without switching off the engine.

Note! If the engine is switched off, the stored fault status will be erased and the test drive will have to be repeated.

Read off the diagnostic status and fault status for the diagnostic trouble code (DTC) by selecting the relevant diagnostic trouble code (DTC) from the list.
Check the fault status for the diagnostic trouble code (DTC) when the diagnostic is "Complete". If the function is correct, the fault status must be "No fault found" when the diagnostic is complete.





Is the function OK?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFICATION FAILED - Fault-tracing information

VERIFIED - Fault Found

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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 - FAULT-TRACING FAILED

No - Attempt New Test

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FAULT-TRACING FAILED - FAULT-TRACING FAILED

Attempt New Test - Checking the components and wiring

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