Signal Too Low - Permanent Fault

Signal too low. Permanent fault

Checking components and wiring
Check the resistance of the heated oxygen sensor (HO2S) between terminals #3 and #4.
Check the signal cable between heated oxygen sensor (HO2S) terminal #4 and control module terminal #A18 (#A18). Check for a short-circuit to ground.
Remedy as necessary.

Other information
- To connect the breakout box / access the control module, see Connecting the breakout box, B5244T5, B5254T2 Connecting the Breakout Box
- To access or replace the heated oxygen sensor (HO2S), see Heated oxygen sensor (HO2S), replacing Heated Oxygen Sensor (HO2S), Replacing
- For resistance values, see Component specifications Specifications
- For information about signals on 5 cylinder engines, see Signal specification Signal Specification, ECM
- For information about signals on 6 cylinder engines, see Signal specification Signal Specification, ECM
- Checking wiring and terminals Checking Wiring And Terminals.














Continue - Verification

-------------------------------------------------

Verification




Verification

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








- Ignition off.
- Reinstall components, reconnect connectors etc.
- Start the engine and let it idle.
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 - VERIFIED

No - VERIFICATION FAILED

------------------------

VERIFICATION FAILED - Fault-tracing information

VERIFIED - Fault Found

-------------------------------------------------

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

------------------------

FAULT-TRACING FAILED - FAULT-TRACING FAILED

Attempt New Test - Checking components and wiring

-------------------------------------------------