Diagnostic Aids

Check for poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. If harness appears to be okay, use DVOM to observe suspect driver circuits at PCM while moving connectors and harnesses. See article. A change in display will indicate location of fault. Check for poor, loose or corroded terminals or harness connectors in instrument cluster harness.

If RPL turns off when PCM harness connectors are disconnected, RPL driver wiring is not at fault. If RPL driver circuit tests okay, instrument cluster is faulty.