Cooling Fan Inoperative
WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
Cooling Fan Inoperative
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views DEFINITION: One or both engine cooling fan motors do not operate properly in high or low speed modes. |
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| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 |
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Go to Step 3 | Go to Step 4 |
| 3 |
IMPORTANT:
Before the powertrain control module (PCM) or engine control module (ECM) changes the speed of the cooling fans, a 3 second delay will occur. With a scan tool, command the Fans High Speed ON and OFF.Do the high speed engine cooling fans turn ON and OFF with each command? |
Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 11 |
| 4 |
IMPORTANT:
Following this step, do NOT remove the 20-amp fused jumper wire that is connected during this step. While performing the following steps, use a second 20-amp fused jumper wire.
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Go to Step 13 | Go to Step 5 |
| 5 |
|
Go to Step 14 | Go to Step 6 |
| 6 | Connect a 20-amp fused jumper between the battery positive voltage circuit of the cooling fan 2 relay and the cooling fan motor supply voltage circuit of the cooling fan 2 relay. Does the left cooling fan operate in high speed? |
Go to Step 9 | Go to Step 7 |
| 7 |
|
Go to Step 16 | Go to Step 8 |
| 8 | Connect a 20-amp fused jumper wire from the cooling fan motor supply voltage circuit of the left cooling fan electrical connector to a good ground. Does the right cooling fan operate in high speed? |
Go to Step 20 | Go to Step 21 |
| 9 |
|
Go to Step 17 | Go to Step 10 |
| 10 | Connect a 20-amp fused jumper wire from battery positive voltage to the cooling fan low reference circuit of the right cooling electrical connector. Does the left cooling fan operate in high speed? |
Go to Step 18 | Go to Step 22 |
| 11 | Is the left cooling fan operating properly in high speed? | Go to Step 12 | Go to Step 15 |
| 12 |
|
Go to Step 14 | Go to Step 19 |
| 13 | Inspect for poor connections at the cooling fan 1 relay. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 28 | Go to Step 23 |
| 14 | Inspect for poor connections at the cooling fan 2 relay. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 28 | Go to Step 24 |
| 15 | Inspect for poor connections at the cooling fan 3 relay. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 28 | Go to Step 25 |
| 16 | Inspect for poor connections at the harness connector of the left cooling fan. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 28 | Go to Step 26 |
| 17 | Inspect for poor connections at the harness connector of the right cooling fan. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 28 | Go to Step 27 |
| 18 | Repair the right cooling fan motor supply voltage circuit. Refer to Wiring Repairs
. Did you complete the repair? |
Go to Step 28 | - |
| 19 | Repair the left cooling fan ground circuit. Refer to Wiring Repairs
. Did you complete the repair? |
Go to Step 28 | - |
| 20 | Repair the right cooling fan ground circuit. Refer to Wiring Repairs
. Did you complete the repair? |
Go to Step 28 | - |
| 21 | Repair the left cooling fan motor supply voltage circuit. Refer to Wiring Repairs
. Did you complete the repair? |
Go to Step 28 | - |
| 22 | Repair the cooling fan low reference circuit. Refer to Wiring Repairs
. Did you complete the repair? |
Go to Step 28 | - |
| 23 | Replace the cooling fan 1 relay. Is the repair complete? |
Go to Step 28 | - |
| 24 | Replace the cooling fan 2 relay. Is the repair complete? |
Go to Step 28 | - |
| 25 | Replace the cooling fan 3 relay. Is the repair complete? |
Go to Step 28 | - |
| 26 | Replace the left cooling fan. Refer to Cooling Fan and Shroud Replacement . Is the repair complete? |
Go to Step 28 | - |
| 27 | Replace the right cooling fan. Refer to Cooling Fan and Shroud Replacement . Is the repair complete? |
Go to Step 28 | - |
| 28 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 3 |