GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Engine Cooling Schematics

Connector End View Reference: Cooling System Connector End Views

DEFINITION: One or both engine coolfan motors run continuously in high or low speed.

1

Did you perform the Engine Cooling Diagnostic System Check?

Go to Step 2

Go To Diagnostic System Check - Engine Cooling

2

Turn ON the ignition, with the engine OFF.

Are one or both coolfans ON?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

3

Are both coolfans running continuously?

Go to Step 5

Go to Step 4

4

Remove the coolfan 3 relay.

Did the right coolfan turn OFF?

Go to Step 6

Go to Step 7

5

Repair the short to voltage in the left coolfan motor supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 8

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6

Repair the short to voltage in the left coolfan low reference circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 8

--

7

Repair the short to voltage in the right coolfan motor supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 8

--

8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2