Signal Too High. Permanent Fault
Signal too high. Permanent fault
Checking wiring and components
Check the heated oxygen sensor (HO2S) resistance between #1 and #2.
Check signal cable between heated oxygen sensor (HO2S) #2 and engine control module (ECM) #A36 (#A36) for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault
Hint: Use an electrician's screwdriver with at least a 3 W bulb to determine whether the cable is short-circuited to supply voltage.
Remedy as necessary.
Other information
- Connecting the breakout box/accessing the control module, see Connecting the breakout box, B5254T2 Connecting the Test Box.
- To access/replace the heated oxygen sensor (HO2S), see Heated oxygen sensors (HO2S), replacing Heated Oxygen Sensor (HO2S), Replacing.
- For resistance values, see Component specifications Specifications.
- For information about signals, see Signal specification Signal Specification.
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.
Read off the rear 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 wiring and components
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