Initial Inspection and Diagnostic Overview

NOTE: The powertrain control module (PCM) controls the electric cooling fan while receiving information from the engine coolant temperature sensor (ECT sensor). The Quick Test will define 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 but a condition still exists, use the following steps to diagnose and correct the condition.

When the engine coolant temperature reaches 113° C (236° F) and the A/C system is on, the PCM will cycle the A/C compressor on and off at 10 second intervals and activate the condenser high fan control relay and the high fan control relay. The cycling will continue until the engine coolant temperature reaches 107° C (225° F).

1. 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.
^ Damaged ECT sensor.

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