Faulty Signal

Faulty signal

Checking components
Check the exhaust system for air leakage
Check the cable for a short-circuit to supply voltage or ground.
Check between:
- Engine control module (ECM) #A91 (#B31) and lambda sond #5.
- Engine control module (ECM) #A68 (#B8) and lambda sond #6 (wiring for pump current).
- Engine control module (ECM) #A92 (#B32) and lambda sond #2 (wiring for calibration current).
Check the cable for an open-circuit.
Check between:
- Engine control module (ECM) #A67 (#B7) and lambda sond #1.

Hint: If the above fault-tracing does not remedy the fault, try replacing the heated oxygen sensors (HO2S), as the diagnostic trouble code (DTC) can also be stored by a defective front/rear heated oxygen sensor (HO2S).

Remedy as necessary.

Other information
- Air leakage exhaust system, check Air Leakage Exhaust System, Check
- 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.




- Reinstall the connectors, components etc.
- Test drive the car at an even speed (engine speed (RPM) above 2000 rpm) for at least 10 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 out the deviation between the front and rear heated oxygen sensor (HO2S).
Check that the value is between -0.03 and +0.03.





Is the value 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

Attempt New Test - Checking components

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