FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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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:
- The cable between engine control module (ECM) terminal #A93 (#B33) and heated oxygen sensor (HO2S) terminal #5
- The cable for pump current between engine control module (ECM) terminal #A70 (#B10) and heated oxygen sensor (HO2S) terminal #6
- The cable for calibration current between engine control module (ECM) terminal #B94 (#B34) and heated oxygen sensor (HO2S) terminal #2.
Check the cable between engine control module (ECM) terminal #A69 (#B9) and heated oxygen sensor (HO2S) terminal #1. Check for an open-circuit.

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
- Oxygen sensor (Catalyst monitor sensor) Oxygen Sensor (Catalyst Monitor Sensor)
- 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.
- 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




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 components

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