GM Service Manual Online
For 1990-2009 cars only

Important: Review the system operation in order to familiarize yourself with the system functions. Refer to the following:

    •  Cooling System Description and Operation
    •  Cooling Fan Description and Operation

Visual/Physical Inspection

    • Inspect for aftermarket devices which could affect the operation of the Cooling System. Refer to Checking Aftermarket Accessories.
    • Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

    •  Cooling Fan Always On
    •  Cooling Fan Inoperative
    •  Engine Overheating
    •  Loss of Coolant
    •  Thermostat Diagnosis
    •  Engine Fails To Reach Normal Operating Temperature