Radiator and A/C Condenser Fan Low Speed Circuit Troubleshooting
Radiator and A/C Condenser Fan Low Speed Circuit TroubleshootingNOTE:
- Do not use this troubleshooting procedure if the A/C compressor is inoperative. Refer to the symptom troubleshooting index. Symptom Related Diagnostic Procedures
- Before performing symptom troubleshooting, check for powertrain DTCs.
1. Check the No. 9 (20 A) fuse in the under-hood fuse/relay box, and the No. 30 (7.5 A) fuse in the under-dash fuse/relay box.
Are the fuses OK?
YES - Go to step 2.
NO - Replace the fuse(s), and recheck.
2. Remove the A/C condenser fan relay from the under-hood fuse/relay box, and test it.
Is the relay OK?
YES - Go to step 3.
NO - Replace the A/C condenser fan relay.
3. Measure the voltage between the A/C condenser fan relay 4P socket terminal No. 1 and body ground.
Is there battery voltage?
YES - Go to step 4.
NO - Replace the under-hood fuse/relay box.
4. Connect the A/C condenser fan relay 4P socket terminals No. 1 and No. 2 with a jumper wire.
Do the A/C condenser and radiator fans run?
YES - Go to step 5.
NO - Go to step 12.
5. Disconnect the jumper wire.
6. Turn the ignition switch ON (II).
7. Measure the voltage between the A/C condenser fan relay 4P socket terminal No. 3 and body ground.
Is there battery voltage?
YES - Go to step 8.
NO - Go to step 32.
8. Turn the ignition switch OFF.
9. Reinstall the A/C condenser fan relay.
10. Turn the ignition switch ON (II).
11. Using the backprobe set, measure the voltage between the PCM connector E (31P) and terminal No. 6 body ground with the PCM connectors connected.
Is there battery voltage?
YES - Check for loose wires or poor connections at PCM connector A (31P) terminal No. 6. If the connections are good, substitute a known-good PCM, and recheck. If the symptom/indication goes away, replace the original PCM, then perform the PCM idle learn procedure.
NO - Repair open in the wire between the A/C condenser fan relay and the PCM.
12. Disconnect the jumper wire.
13. Reinstall the A/C condenser fan relay.
14. Disconnect the A/C condenser fan 2P connector.
15. Turn the ignition switch ON (II), then turn the A/C and fan control buttons ON.
16. Measure the voltage between the A/C condenser fan 2P connector terminal No. 2 and body ground.
Is there battery voltage?
YES - Go to step 17.
NO - Repair open in the wire between the A/C condenser fan relay and the A/C condenser fan.
17. Push the OFF button, then turn the ignition switch OFF.
18. Reconnect the A/C condenser fan 2P connector.
19. Connect the A/C condenser fan 2P connector terminal No. 1 to body ground with a jumper wire.
20. Turn the ignition switch ON (II), then push the A/C and fan control buttons ON.
Does the A/C condenser fan run?
YES - Go to step 21.
NO - Replace the A/C condenser fan motor.
21. Push the OFF button, then turn the ignition switch OFF.
22. Disconnect the jumper wire.
23. Remove the fan control relay from the auxiliary under-hood relay box A, and test it.
Is the relay OK?
YES - Go to step 24.
NO - Replace the fan control relay.
24. Turn the ignition switch ON (II), then push the A/C and fan control buttons ON.
25. Measure the voltage between the fan control relay 5P socket terminal No. 1 and body ground.
Is there battery voltage?
YES - Go to step 26.
NO - Repair open in the wire between the A/C condenser fan and the fan control relay.
26. Push the OFF button, then turn the ignition switch OFF.
27. Remove the radiator fan relay from the under-hood fuse/relay box.
28. Check for continuity between the fan control relay 5P socket terminal No. 4 and the radiator fan relay 4P socket terminal No. 1.
Is there continuity?
YES - Go to step 29.
NO - Repair open in the wire between the fan control relay and the radiator fan relay.
29. Disconnect the radiator fan 2P connector.
30. Check for continuity between the radiator fan relay 4P socket terminal No. 1 and the radiator fan 2P connector terminal No. 2.
Is there continuity?
YES - Go to step 31.
NO - Repair open in the wire between the radiator fan relay and the radiator fan.
31. Check for continuity between the radiator fan 2P connector terminal No. 1 and body ground.
Is there continuity?DVOM
YES - Replace the radiator fan motor.
NO - Check for an open in the wire between the radiator fan and body ground. If the wire is OK, check for poor ground at G301.
32. Remove A/C diode A from under the dashboard.
33. Using the diode setting (-M-) on a DVOM, check for current flow in both directions between the No. 1 and No. 2 terminals of A/C diode A.
Is there current flow in only one direction?
YES - Go to step 34.
NO - Replace A/C diode A.
34. Turn the ignition switch ON (II)
35. Measure the voltage between A/C diode A 2P socket terminal No. 2 and body ground.
Is there battery voltage?
YES - Repair open in the wire between A/C diode A pin 1 and the A/C condenser fan relay.
NO - Repair open in the wire between the No, 30 fuse in the under-dash fuse/relay box and A/C diode A pin 2.