General Information

An intermittent problem is defined as one that does NOT happen while you are testing the system or actually running through self-diagnosis system steps.

If "CHECK ENGINE" light does come "ON", the ECU may store a trouble code in memory. The trouble codes usually only set in memory if the circuit fails (high or low). If a sensor drifts out of specification, a trouble code may not set. To locate sensors out of specification, test ECU signals using appropriate J - PIN VOLTAGE charts in this section.