Diagnostic Aids

If cooling fan operates normally but an overheating condition exists, check coolant temperature sensor temperature-to-resistance value. See Code 15 chart in appropriate TESTS W/CODES article in this section. Replace coolant temperature sensor if not within specifications. If coolant temperature sensor is okay, check for basic cooling system problem.

Fig 1: Chart C-12A Schematic (3.3L "A" Body) Cooling Fan Circuit Diagnosis

Courtesy of GENERAL MOTORS CORP.

Fig 2: Chart C-12A Flow Chart (1 Of 3)(3.3L "A" Body) Cooling Fan Circuit Diagnosis

Courtesy of GENERAL MOTORS CORP.