Diagnostic Aids
Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. The cooling fan control module is sensitive to heat. If the module is covered with thick mud or dirt it may cause the cooling fan module to overheat and command the fan on at undesired times.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views DEFINITION: Engine cooling fan operates all the time when the vehicle is started or not started. | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Important: The vehicle must be allowed to cool down. The HVAC control system must be in the OFF position and the coolant temperature must stay below 91° (195°F) for this diagnostic.
Is the cooling fan ON? | -- | Go to Step 3 | Go to Diagnostic Aids |
Does the test lamp illuminate? | -- | Go to Step 7 | Go to Step 4 | |
4 | Inspect the battery positive voltage circuit of the cooling fan motor for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 5 |
5 | Inspect for poor connections at the fan control module. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 6 |
6 | Replace the fan control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 9 | -- |
7 | Inspect for poor connections at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 8 |
8 | Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 9 | -- |
9 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |
