Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information ECM-243B

Condition




The engine control module (ECM) monitors the operation of the front heated oxygen sensor (HO2S) by checking its signal. The diagnostic trouble code (DTC) is stored if the voltage for the heated oxygen sensor (HO2S) preheating disrupts the heated oxygen sensor (HO2S) signal.

Substitute value
- The heated oxygen sensor (HO2S) control is disabled
- Three-way catalytic converter (TWC) diagnostics are disabled.

Possible source
- One of the cables for heated oxygen sensor (HO2S) preheating is short-circuited to the probe's other signal cables
- Damaged front heated oxygen sensor (HO2S).

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