Cooling Fan Inoperative (L66)
Cooling Fan Inoperative (L66)
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Engine Cooling Schematics (L61) or Engine Cooling Schematics (L66) Connector End View Reference: Cooling System Connector End Views DEFINITION: One or both cooling fan motors are inoperative in either high, low, or both speeds. |
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| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 | Test cool fan 1, cool fan 2 and cool fan 3 relay control circuits for an open. Did you find and correct the condition? |
Go to Step 29 | Go to Step 3 |
| 3 |
|
Go to Step 4 | Go to Step 5 |
| 4 |
IMPORTANT:
A 3 second delay occurs before the powertrain control module (PCM) changes the cooling fan speed. With a scan tool, command the Fans Control 2 and 3 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 in Wiring Systems | Go to Step 12 |
| 5 |
IMPORTANT:
Do NOT remove the 20-amp fused jumper wire connected during this step. Use a second 20-amp fused jumper wire while performing the following steps.
|
Go to Step 14 | Go to Step 6 |
| 6 |
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Go to Step 15 | Go to Step 7 |
| 7 | Reconnect the second 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 right cooling fan operate in high speed? |
Go to Step 10 | Go to Step 8 |
| 8 |
|
Go to Step 17 | Go to Step 9 |
| 9 | Reconnect the second 20-amp fused jumper wire from the cooling fan motor supply voltage circuit of the right cooling fan electrical connector to a good ground. Does the left cooling fan operate in high speed? |
Go to Step 21 | Go to Step 22 |
| 10 |
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Go to Step 18 | Go to Step 11 |
| 11 | Reconnect the second 20-amp fused jumper wire from battery positive voltage to the left cooling fan low reference circuit of the left cooling fan electrical connector. Does the right cooling fan operate in high speed? |
Go to Step 19 | Go to Step 23 |
| 12 | Does the right cooling fan operate in high speed? | Go to Step 13 | Go to Step 16 |
| 13 |
|
Go to Step 15 | Go to Step 20 |
| 14 | Inspect for poor connections at the cooling fan 1 relay. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 29 | Go to Step 24 |
| 15 | Inspect for poor connections at the cooling fan 2 relay. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 29 | Go to Step 25 |
| 16 | Inspect for poor connections at the cooling fan 3 relay. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 29 | 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
in Wiring Systems. Did you find and correct the condition? |
Go to Step 29 | Go to Step 27 |
| 18 | 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
in Wiring Systems. Did you find and correct the condition? |
Go to Step 29 | Go to Step 28 |
| 19 | Repair the left cooling fan motor supply voltage circuit. Refer to Wiring Repairs
in Wiring Systems. Did you complete the repair? |
Go to Step 29 | - |
| 20 | Repair the left cooling fan motor ground circuit. Refer to Wiring Repairs
in Wiring Systems. Did you complete the repair? |
Go to Step 29 | - |
| 21 | Repair the right cooling fan motor ground circuit. Refer to Wiring Repairs
in Wiring Systems. Did you complete the repair? |
Go to Step 29 | - |
| 22 | Repair the right cooling fan motor supply voltage circuit. Refer to Wiring Repairs
in Wiring Systems. Did you complete the repair? |
Go to Step 29 | - |
| 23 | Repair the left cooling fan low reference circuit. Refer to Wiring Repairs
in Wiring Systems. Did you complete the repair? |
Go to Step 29 | - |
| 24 | Replace the cooling fan 1 relay. Did you complete the replacement? |
Go to Step 29 | - |
| 25 | Replace the cooling fan 2 relay. Did you complete the replacement? |
Go to Step 29 | - |
| 26 | Replace the cooling fan 3 relay. Did you complete the replacement? |
Go to Step 29 | - |
| 27 | Replace the right cooling fan. Refer to Cooling Fan Motor Replacement - Electric (L66) . Did you complete the replacement? |
Go to Step 29 | - |
| 28 | Replace the left cooling fan. Refer to Cooling Fan Motor Replacement - Electric (L66) . Did you complete the replacement? |
Go to Step 29 | - |
| 29 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 3 |