Signal Too Low - Permanent Fault

ECM-2810 FRONT HEATED OXYGEN SENSOR (HO2S), PREHEATING
SIGNAL TO LOW - PERMANENT FAULT

Checking wiring and components



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

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

Read 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.