Cooling Fan Inoperative

If diagnostic system check has been performed, go to next step. If diagnostic system check has not been performed, see DIAGNOSTIC SYSTEM CHECK .

NOTE: Cooling fan 1 relay and cooling fan 2 relay are improperly identified in underhood fuse block. See WIRING DIAGRAMS for proper identification.

Install scan tool. Turn ignition on, engine off. Using scan tool, command fans low speed on and off. If low speed engine cooling fans turn on and off with each command, go to next step. If low speed engine cooling fans do not turn on and off with each command, go to step 4.

NOTE: Before PCM changes speed of cooling fans, a 3-second delay occurs.

Using scan tool, command fans high speed on and off. If high speed engine cooling fans turn on and off with each command, problem is intermittent. If high speed engine cooling fans do not turn on and off with each command, go to step 12.
Turn ignition off. Disconnect cooling fan 1 relay. Turn ignition on, engine off. Probe battery voltage circuit of cool fan 1 relay switch side using test light connected to ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 19.

NOTE: Following this step, do not remove fused jumper (20-amp) that is connected during this step. While performing the following steps, use a second fused jumper (20-amp).

Connect 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 14. If both cooling fans do not operate in low speed, go to next step.
Disconnect cooling fan series/parallel relay. Connect second fused jumper (20-amp) between cooling fan low reference circuit (White wire) of cooling fan series/parallel relay and right cooling fan motor supply voltage circuit (Light Blue wire) of cooling fan series/parallel relay. If both cooling fans operate in low speed, go to step 15. 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 series/parallel relay and cooling fan motor supply voltage circuit (Light Blue wire) of cooling fan series/parallel relay. If right cooling fan operates in high speed, go to step 10. If right cooling fan does not operate in high speed, go to next step.
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 17. 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 22. If left cooling fan does not operate in high speed, go to step 23.
Install cooling fan series/parallel 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 18. If right cooling fan does not operate in high speed, go to next step.
Connect second fused jumper (20-amp) between battery voltage and cooling fan low reference circuit (White wire) of left cooling fan electrical connector. If right cooling fan operates in high speed, go to step 20. If right cooling fan does not operate in high speed, go to step 24.
If right cooling fan is operating properly in high speed, go to next step. If right cooling fan is not operating properly in high speed, go to step 16.
Disconnect cooling fan series/parallel relay. Connect second fused jumper (20-amp) between cooling fan low reference circuit (White wire) of cooling fan series/parallel relay and ground circuit (Black wire) of cooling fan series/parallel relay. If left cooling fan operates in high speed, go to step 15. If left cooling fan does not operate in high speed, go to step 21.
Check cooling fan 1 relay connector for poor connections. If problem was found, repair as necessary. After repairs, go to step 30. If problem was not found, go to step 25.
Check cooling fan series/parallel relay connector for poor connections If problem was found, repair as necessary. After repairs, go to step 30. If problem was not found, go to step 26.
Check cooling fan 2 relay connector for poor connections. If problem was found, repair as necessary. After repairs, go to step 30. If problem was not found, go to step 27.
Check right cooling fan connector for poor connections. If problem was found, repair as necessary. After repairs, go to step 30. If problem was not found, go to step 28.
Check left cooling fan connector for poor connections. If problem was found, repair as necessary. After repairs, go to step 30. If problem was not found, go to step 29.
Repair battery voltage circuit of cool fan 1 relay switch side. After repairs, go to step 30.
Repair left cooling fan motor supply voltage circuit (Gray wire). After repairs, go to step 30.
Repair left cooling fan ground circuit (Black wire). After repairs, go to step 30.
Repair right cooling fan motor ground circuit (Black wire). After repairs, go to step 30.
Repair right cooling fan motor supply voltage circuit (Light Blue wire). After repairs, go to step 30.
Repair left cooling fan low reference circuit (White wire). After repairs, go to step 30.
Replace cooling fan 1 relay. After repairs, go to step 30.
Replace cooling fan series/parallel relay. After repairs, go to step 30.
Replace cooling fan 2 relay. After repairs, go to step 30.
Replace right cooling fan. After repairs, go to step 30.
Replace left cooling fan. After repairs, go to next step.
Operate system to verify repair.