Diagnostic Aids

Check for a stuck open thermostat, cooling fan always on, corroded connectors or resistance in circuit, very low ambient temperature or faulty ECT sensor.

An intermittent malfunction may be caused by a poor connection, rubbed-through wire insulation, or a wire broken inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, or poor terminal-to-wire connections before component replacement.