Initial Inspection and Diagnostic Overview

The powertrain control module (PCM) controls the engine cooling fan system and receives information from the engine coolant temperature sensor (ECT sensor). The Quick Test will determine if there is a problem with the PCM circuit and send you to the proper Pinpoint Test. If a diagnostic trouble code is not received in the Quick Test, and a condition still exists, use the following steps to diagnose and correct the condition.

1. Verify customer concern by running the engine.
2. Visually inspect the following components of the engine cooling system.:
^ Damaged radiator, radiator cap or radiator draincock.
^ Damaged hoses.
^ Damaged fan blades.
^ Improperly mounted engine cooling fan motor.
^ Improperly mounted fan shroud.
^ Coolant level.
^ Blown Fuses:
- 15A ENGINE
- 40A COOLING FAN
^ Corroded or loose connections.
^ Damaged or corroded wiring harness.
^ Damaged or corroded relays.

3. Check the coolant level and condition.
4. Check the engine cooling fan motor, fan blade and fan shroud for damage and proper mounting.
5. Check the radiator hoses for cracking, bulging, soft spots, or hardness.