Signal Too Low

Signal too low

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 #A70 (#B10). Check for a short-circuit to ground.
Remedy as necessary.

Other information
- For information about signals, see Signal specification Signal Specification
- 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), see Heated oxygen sensor (HO2S), replacing Heated Oxygen Sensor (HO2S), Replacing
- For resistance values, see Component specifications Specifications
- 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
- Reinstall the components, reconnect the connectors etc.
- Start the engine. Allow the engine to idle.
Read off the diagnostic trouble code (DTC) status for the front heated oxygen sensor (HO2S).
The text NOT READY is displayed if the diagnosis is underway.









Is NOT DETECTED 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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