Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information ECM-223B

Condition




The engine control module (ECM) controls the preheating of the rear heated oxygen sensor (HO2S) by pulsing the current to the positive temperature coefficient (PTC) element in the heated oxygen sensor (HO2S). Pulse lengths are dependent on the temperature of the heated oxygen sensor (H02S).
The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal is lower than a certain value when preheating is deactivated.

Substitute value
- The fuel trim is shut off.

Possible source
- Contact resistance and oxidation in the terminals
- Open-circuit in the power supply from the system relay
- Damaged heated oxygen sensor (HO2S).

Fault symptom[s]
- Malfunction indicator lamp (MIL) lit.