ECM-122C

Diagnostic trouble code (DTC) information ECM-122C

Condition




The engine control module (ECM) calculates the anticipated mass air flow. The calculation is based on a number of parameters. The calculated value for mass air flow is then compared with the measured value from the mass air flow (MAF) sensor.
The diagnostic trouble code (DTC) is stored if the engine control module (ECM) detects that the value for the measured air mass is higher than the calculated value for air mass.
The diagnostic trouble code (DTC) can be diagnosed when the engine is running.

Substitute value
- Calculated boost pressure
- Calculated air mass
- Rear heated oxygen sensor (HO2S) control shut off
- Misfire diagnostic shut off.

Possible source
- Short-circuit to supply voltage in the signal cable
- Open-circuit in the ground lead
- Damaged mass air flow (MAF) sensor.

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