Signal Missing. Permanent Fault

Signal missing. Permanent fault

Checking components and wiring

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

Check the signal cable (+) between heated oxygen sensor (HO2S) terminal #1 and control module terminal #A41 (#A41). Check the signal cable (-) between heated oxygen sensor (HO2S) terminal #5 and control module terminal #A42 (#A42). Check for a short-circuit to each other.
Check the power supply to heated oxygen sensor (HO2S) terminal #3 and the signal cable between heated oxygen sensor (HO2S) terminal #4 and control module terminal #A18 (#A18). Check for a short-circuit to the other cables for the heated oxygen sensor (HO2S).
Try a new heated oxygen sensor (HO2S) if the wiring is OK.
Remedy as necessary.

Other information
- To connect the breakout box / access the control module, see Connecting the breakout box, B5254T2 Connecting the Test Box
- To access or replace the heated oxygen sensor (HO2S) for the C70, S70, V70 -2000 and V70XC, see Adapter wiring switch, replacing Adapter Wiring Switch, Replacing. For other models, see Heated oxygen sensor (HO2S), replacing Heated Oxygen Sensor (HO2S), Replacing
- For information about signals on 5 cylinder engines, see Signal specification Signal Specification
- For information about signals on 6 cylinder engines, see Signal specification Signal Specification
- 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 connectors, reinstall components.
- Start the engine and let it idle for a maximum of 5 minutes.
Read off the front heated oxygen sensor (HO2S) signal diagnostic trouble code (DTC) status.
The text NOT READY is displayed if diagnosis is underway.









Is FAULT NOT REGISTERED displayed?

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 components and wiring

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