Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information

Condition
Diagnostic trouble code (DTC) ECM-3502 is stored if the control module registers that the engine misfires to such an extent that exhaust emissions increase (the extent varies with load and engine speed (RPM)).

Substitute value
- three-way catalytic converter (TWC) diagnosis shut off
- leakage diagnosis shut off
- rear heated oxygen sensor control shut off

Possible source
- defective spark plugs
- blocked/leaking injectors
- uneven compression
- air leakage
- faulty fuel pressure
- fuel stoppage
- water in spark plug wells
- contaminated or faulty fuel
- repeated cold starting where the engine coolant temperature (ECT) has not reached normal operating temperature between starts.

Fault symptom[s]
- engine misfires
- engine difficult to start
- poor performance
- uneven idle
- engine not firing on all cylinders