Cooling Fan Inoperative
- If diagnostic system check has not been performed, see DIAGNOSTIC SYSTEM CHECK . If diagnostic system check has been performed, go to next step.
- Install scan tool. Turn ignition on, engine off. Using scan tool, command fans low speed on and off. If low speed cooling fans turn on and off with each command, go to next step. If low speed cooling fans do not turn on and off with each command, go to step 4.
- Using scan tool, command fans high speed on and off. If high speed cooling fans turn on and off with each command, problem is intermittent. If high speed cooling fans do not turn on and off with each command, go to step 11.
- Disconnect the cooling fan 1 relay. Connect first fused jumper (20 amp) between battery voltage circuit of cooling fan 1 relay and cooling fan motor supply voltage circuit (Gray wire) of cooling fan 1 relay. If both cooling fans operate in low speed, go to step 13. If both cooling fans do not operate in low speed, go to next step.
- Disconnect cooling fan 2 relay. Connect second fused jumper (20 amp) between left cooling fan motor low reference circuit (White wire) of cooling fan 2 relay and right cooling fan motor supply voltage circuit (Light Blue wire) of cooling fan 2 relay. If both cooling fans operate in low speed, go to step 14. If both cooling fans do not operate in low speed, go to next step.
- Connect second fused jumper (20 amp) between battery voltage circuit of cooling fan 2 relay and cooling fan motor supply voltage circuit (Light Blue wire) of cooling fan 2 relay. If right cooling fan operates in high speed, go to step 9. If right cooling fan does not operate in high speed, go to next step.
- Install cooling fan 2 relay. Disconnect right cooling fan electrical connector. Connect second fused jumper (20 amp) between terminals of right cooling fan electrical connector. If left cooling fan operates in high speed, go to step 16. If left cooling fan does not operate in high speed, go to next step.
- Connect second fused jumper (20 amp) between cooling fan motor supply voltage circuit (Light Blue wire) of right cooling fan electrical connector and ground. If left cooling fan operates in high speed, go to step 20. If left cooling fan does not operate in high speed, go to step 21.
- Install cooling fan 2 relay. Disconnect left cooling fan electrical connector. Connect second fused jumper (20 amp) between terminals of left cooling fan electrical connector. If right cooling fan operates in high speed, go to step 17. If right cooling fan does not operate in high speed, go to next step.
- Connect second fused jumper (20 amp) between battery voltage and left cooling fan low reference circuit (White wire) of left cooling fan electrical connector. If right cooling fan operates in high speed, go to step 18. If right cooling fan does not operate in high speed, go to step 22.
- If right cooling fan operates in high speed, go to next step. If right cooling fan does not operate in high speed, go to step 15.
- Disconnect cooling fan 2 relay. Connect fused jumper (20 amp) between left cooling fan low reference circuit (White wire) of cooling fan 2 relay and ground circuit of cooling fan 2 relay. If left cooling fan operates properly in high speed, go to step 14. If left cooling fan does not operate properly in high speed, go to step 19.
- Check cooling fan 1 relay connector for poor connections. If problem was found, repair as necessary. After repairs, go to step 28. If problem was not found, go to step 23.
- Check cooling fan 2 relay connector for poor connections. If problem was found, repair as necessary. After repairs, go to step 28. If problem was not found, go to step 24.
- Check cooling fan 3 relay connector for poor connections. If problem was found, repair as necessary. After repairs, go to step 28. If problem was not found, go to step 25.
- Check right cooling fan connector for poor connections. If problem was found, repair as necessary. After repairs, go to step 28. If problem was not found, go to step 26.
- Check left cooling fan connector for poor connections. If problem was found, repair as necessary. After repairs, go to step 28. If problem was not found, go to step 27.
- Repair left cooling fan motor supply voltage circuit (Gray wire). After repairs, go to step 28.
- Repair left cooling fan motor ground circuit. After repairs, go to step 28.
- Repair right cooling fan motor ground circuit (Black wire). After repairs, go to step 28.
- Repair right cooling fan motor supply voltage circuit (Light Blue wire). After repairs, go to step 28.
- Repair left cooling fan low reference circuit (White wire). After repairs, go to step 28.
- Replace cooling fan 1 relay. After repairs, go to step 28.
- Replace cooling fan 2 relay. After repairs, go to step 28.
- Replace cooling fan 3 relay. After repairs, go to step 28.
- Replace right cooling fan. After repairs, go to step 28.
- Replace left cooling fan. After repairs, go to next step.
- Operate system to verify repair.
NOTE:
Before PCM changes speed of cooling fans, a 3-second delay will occur.
NOTE:
Do not remove fused jumper (20 amp) connected during this step. Use a second fused jumper (20 amp) while performing the following steps.