Diagnostic Aids
An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Check for:
- Poor Connection Or Damaged Harness: Inspect PCM harness for short to ground in circuit No. 472 (Tan wire), improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection, and damaged harness.
- Intermittent Test: Observe IAT on Tech-1 while moving related connectors and wiring harness with warm engine running. If failure is induced, IAT display will change to a 297°F (147°C) temperature reading. This may assist in isolating the location of the malfunction.