Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information ECM-3502

Condition
If the engine control module (ECM) detects a particular number of misfires during a set number of crankshaft revolutions, this will be interpreted as misfires which increase emissions. The diagnostic trouble code (DTC) will be stored. In certain cases, the diagnostic trouble code (DTC) qualifier can also indicate which cylinder is misfiring.
The misfire diagnostic is active after the engine is started. Also see "Design and function, misfire diagnostic".

Substitute value
- None.

Possible source
- Low fuel level
- Repeated cold starting where the engine coolant temperature (ECT) has not reached normal operating temperature between starts
- Moisture in spark plug wells
- Damaged spark plug
- Contaminated or incorrect fuel
- Incorrect fuel quality (summer fuel in winter, certain markets).
- Air leakage
- Blocked crankcase ventilation.
- Damaged VVT-unit.
- Blocked / leaking injector
- Faulty fuel pressure
- Uneven compression

Fault symptom[s]
- The engine misfires
- The engine is difficult to start
- Deterioration in performance
- Uneven idle
- The engine is not firing on all cylinders.