Diagnostic Aids

When attempting to diagnose an intermittent problem, use scan tool to review malfunction history information. This data can be used to duplicate a problem.

If an open circuit exists on cylinder No. 4, DTC will set, due to polarity and amplitude of the coil during every firing event looking as if cylinder No. 4 is on compression. The PCM thinks cylinder No. 4 is on compression every crankshaft revolution. If engine is misfiring, refer to misfire DTCs for diagnosis. High resistance in the spark plug, wires or connections will also set DTC.