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. Heating/Air Conditioning
- Before performing symptom troubleshooting, check for powertrain DTCs.
1. Check the No. 9 (30 A) fuse in the under-hood fuse/relay box, and the No. 30 (10 A) fuse in the driver's 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 No. 1 terminal of the A/C condenser fan relay 4P socket and body ground.
Is there battery voltage?
YES - Go to step 4.
NO - Replace the under-hood fuse/relay box.
4. Connect the No. 1 and No. 2 terminals of the A/C condenser fan relay 4P socket with a jumper wire.
Do the A/C condenser and radiator fans run?
YES - Go to step 5
NO - Go to step 14.
5. Disconnect the jumper wire.
6. Turn the ignition switch to ON (II).
7. Measure the voltage between the No. 3 terminal of the A/C condenser fan relay 4P socket and body ground.
Is there battery voltage?
YES - Go to step 8.
NO - Go to step 34.
8. Turn the ignition switch to LOCK (0).
9. Reinstall the A/C condenser fan relay.
10. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
11. Disconnect PCM connector A (49P).
12. Connect the PCM connector A (49P) No. 4 terminal to body ground with a jumper wire.
13. Turn the ignition switch to ON (II).
Does the A/C condenser and radiator fans run?
YES - Check for loose wires or poor connections at PCM connector A (49P). If the connections are good, check the PCM grounds. If the grounds are good, substitute a known-good PCM, and recheck. If the symptom/indication goes away, replace the original PCM.
NO - Repair open in the wire between the A/C condenser fan relay and the PCM.
14. Disconnect the jumper wire.
15. Reinstall the A/C condenser fan relay.
16. Disconnect the A/C condenser fan 2P connector.
17. Turn the ignition switch to ON (II), then set the A/C button and fan control dial ON.
18. Measure the voltage between the No. 2 terminal of the A/C condenser fan 2P connector and body ground.
Is there battery voltage?
YES - Go to step 19.
NO - Repair open in the wire between the A/C condenser fan relay and the A/C condenser fan.
19. Set the A/C button and fan control dial OFF, then turn the ignition switch to LOCK (0).
20. Reconnect the A/C condenser fan 2P connector.
21. Connect the No. 1 terminal of the A/C condenser fan 2P connector to body ground with a jumper wire.
22. Turn the ignition switch to ON (II), then set the A/C button and fan control dial ON.
Does the A/C condenser fan run?
YES - Go to step 23.
NO - Replace the A/C condenser fan motor.
23. Set the A/C button and fan control dial OFF, then turn the ignition switch to LOCK (0).
24. Disconnect the jumper wire.
25. Remove the fan control relay from the auxiliary under-hood relay box, and test it.
Is the relay OK?
YES - Go to step 26.
NO - Replace the fan control relay.
26. Turn the ignition switch to ON (II), then set the A/C button and fan control dial ON.
27. Connect the No. 1 terminal of the fan control relay 5P socket to body ground.
Does the A/C condenser fan run?
YES - Go to step 28.
NO - Repair open in the wire between the A/C condenser fan and the fan control relay.
28. Set the A/C button and fan control dial OFF, then turn the ignition switch to LOCK (0).
29. Remove the radiator fan relay from the under-hood fuse/relay box.
30. Check for continuity between the No. 4 terminal of the fan control relay 5P socket and the No. 1 terminal of the radiator fan relay 4P socket.
Is there continuity?
YES - Go to step 31.
NO - Repair open in the wire between the fan control relay and the radiator fan relay.
31. Disconnect the radiator fan 2P connector.
32. Check for continuity between the No. 1 terminal of the radiator fan relay 4P socket and the No. 2 terminal of the radiator fan 2P Connector.
Is there continuity?
YES - Go to step 33.
NO - Repair open in the wire between the radiator fan relay and the radiator fan.
33. Check for continuity between the No. 1 terminal of the radiator fan 2P connector and body ground.
Is there continuity?
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.
34. Turn the ignition switch to LOCK (0).
35. Remove A/C diode A from under-hood fuse/relay box.
36. Using the diode setting 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 37.
NO - Replace A/C diode A.
37. Turn the ignition switch to ON (II).
38. Measure the voltage between the No. 2 terminal of A/C diode A 2P socket and body ground.
Is there battery voltage?
YES - Open between the A/C diode A pin 1 and the A/C condenser fan relay.
NO - Repair open in the wire between the No. 30 (10 A) fuse in the driver's under-dash fuse/relay box and A/C diode A pin 2.