Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Cooling Schematics DEFINITION: One or both engine cooling fan motors do not operate properly in high or low speed modes. | |||
1 | Did you perform the Engine Cooling Diagnostic System Check? | Go to Step 2 | |
2 |
Important: The cooling fan 1 and 2 relays and fuses are improperly identified in the underhood fuse block. Refer to Electrical Center Identification Views in Wiring Systems for proper identification.
Do the low speed engine cooling fans turn ON and OFF with each command? | Go to Step 3 | Go to Step 4 |
3 |
Important:: The cooling fans will remain in low speed operation for 3 seconds before the PCM grounds the high speed fan relay control to turn on the high speed fans. 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 in Wiring Systems | Go to Step 13 |
4 |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 20 |
5 |
Important: Following this step, do not remove the 20-A fused jumper wire that is connected during this step. While performing the following steps, use a second 20-A fused jumper wire. Connect a 20-A fused jumper between the battery positive voltage circuit of the cooling fan 1 relay and the cooling fan motor supply voltage circuit of the cooling fan 1 relay. Do both cooling fans operate in low speed? | Go to Step 15 | Go to Step 6 |
6 |
Do both cooling fans operate in low speed? | Go to Step 16 | Go to Step 7 |
7 | Connect the second 20-A fused jumper between the battery positive voltage circuit of the cooling fan S/P relay and the cooling fan motor supply voltage circuit of the cooling fan S/P relay. Does the right cooling fan operate in high speed? | Go to Step 11 | Go to Step 8 |
8 |
Does the left cooling fan operate in high speed? | Go to Step 24 | Go to Step 9 |
9 | Connect the second 20-A fused jumper wire from the cooling fan motor supply voltage circuit of the right cooling fan electrical connector to the ground circuit of the right cooling fan electrical connector. Does the left cooling fan operate in high speed? | Go to Step 18 | Go to Step 10 |
10 | Connect the second 20-A 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 23 | Go to Step 24 |
11 |
Does the right cooling fan operate in high speed? | Go to Step 19 | Go to Step 12 |
12 | Connect the second 20-A fused jumper wire from battery positive voltage to the cooling fan low reference circuit of the of the left cooling fan electrical connector. Does the right cooling fan operate in high speed? | Go to Step 21 | Go to Step 25 |
13 | Is the right cooling fan operating properly in high speed? | Go to Step 14 | Go to Step 17 |
14 |
Does the left cooling fan operate in high speed? | Go to Step 16 | Go to Step 22 |
15 | 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 31 | Go to Step 26 |
16 | Inspect for poor connections at the cooling fan S/P 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 31 | Go to Step 27 |
17 | 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 31 | Go to Step 28 |
18 | 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 31 | Go to Step 29 |
19 | 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 31 | Go to Step 30 |
20 | Repair the battery positive voltage circuit of the cool fan 1 relay switch side. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 31 | -- |
21 | Repair the left cooling fan motor supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 31 | -- |
22 | Repair the left cooling fan ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 31 | -- |
23 | Repair the right cooling fan motor ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 31 | -- |
24 | Repair the right cooling fan motor supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 31 | -- |
25 | Repair the left cooling fan low reference circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 31 | -- |
26 | Replace the cooling fan 1 relay. Did you complete the repair? | Go to Step 31 | -- |
27 | Replace the cooling fan S/P relay. Did you complete the repair? | Go to Step 31 | -- |
28 | Replace the cooling fan 2 relay. Did you complete the repair? | Go to Step 31 | -- |
29 | Replace the right cooling fan. Refer to Engine Coolant Fan Motor Replacement in Engine Cooling. Did you complete the repair? | Go to Step 31 | -- |
30 | Replace the left cooling fan. Refer to Engine Coolant Fan Motor Replacement in Engine Cooling. Did you complete the repair? | Go to Step 31 | -- |
31 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
