Signal Missing - Permanent Fault

ECM-280A FRONT HEATED OXYGEN SENSOR (HO2S), FAULTY SIGNAL
SIGNAL MISSING - PERMANENT FAULT

Checking wiring and components




CAUTION!
Do not apply rust solvent spray or grease to the Heated Oxygen Sensor (HO2S) connector.

Check signal cable (+) between Heated Oxygen Sensor (HO2S) # 1 and control module # A41 (# A41) and signal cable (-) between Heated Oxygen Sensor (HO2S) # 5 and control module # A42 (# A42) for a short circuit to each other according to [1][2]Checking Wiring and Terminals. Permanent Fault

Check the power supply to Heated Oxygen Sensor (HO2S) # 3 and the signal cable between Heated Oxygen Sensor (HO2S) # 4 and control module # A18 (# A18) for a short-circuit to the Heated Oxygen Sensor (HO2S) other cables according to [1][2]Checking Wiring and Terminals. Permanent Fault

If wiring is OK, try another Heated Oxygen Sensor (HO2S).

Remedy as necessary.

Other information
- Connecting the breakout box/accessing the control module Connecting the Breakout Box (ECM)
- To access/replace the heated oxygen sensor (HO2S), Adapter Wiring Switch, Replacing
- For information about signals, see Diagnostic Parameters and Pinout Values. Signal Description, ME7, B5XX4T


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 - Testing Complete.
No - Continue below.


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.