Radiator and A/C Condenser Fan Low Speed Circuit Troubleshooting
Radiator and A/C Condenser Fan Low Speed Circuit Troubleshooting
NOTE:
- Do not use this troubleshooting procedure if the A/C compressor is inoperative. Refer to the symptom troubleshooting index.
- If A/C refrigerant pressure is abnormal, the radiator fans are controlled based on engine coolant temperature Description and Operation.
- Before doing symptom troubleshooting, check for powertrain DTCs Initial Inspection and Diagnostic Overview.
1. Check the No. 7 (20 A) fuse in the under-hood fuse/relay box, and the No. 36 (10 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. If the fuses blow again, check for a short in the No. 7 (20 A) and No. 36 (10 A) fuses circuit.�
2. Remove the radiator fan relay from the under-hood fuse/relay box, and test it Testing and Inspection.
Is the relay OK?
YES -
Go to step 3.
NO -
Replace the radiator fan relay.�
3. Connect the HDS to the DLC.
4. Turn the ignition switch to ON (II).
5. Turn on the A/C.
6. Check the FAN LOW CTRL in the PGM-FI Data List with the HDS.
Is the FAN LOW CTRL on?
YES -
Go to step 7.
NO -
Substitute a known-good PCM Initial Inspection and Diagnostic Overview, and retest. If the symptom/indication goes away with a known-good PCM, replace the original PCM Service and Repair.�
7. Turn the ignition switch to LOCK (0).
8. Measure the voltage between radiator fan relay 4P socket terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to step 9.
NO -
Replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal/Installation.�
9. Connect radiator fan relay 4P socket terminals No. 1 and No. 2 with a jumper wire.
Do the A/C condenser and radiator fans run on low?
YES -
Go to step 10.
NO -
Go to step 19.
10. Disconnect the jumper wire.
11. Turn the ignition switch to ON (II).
12. Measure the voltage between radiator fan relay 4P socket terminal No. 3 and body ground.
Is there battery voltage?
YES -
Go to step 13.
NO -
Go to step 37.
13. Turn the ignition switch to LOCK (0).
14. Reinstall the radiator fan relay.
15. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
16. Disconnect PCM connector A (44P).
17. Connect PCM connector A (44P) terminal No. 4 to body ground with a jumper wire.
18. Turn the ignition switch to ON (II).
Do the A/C condenser and radiator fans run on low?
YES -
Check for loose wires or poor connections at PCM connector A (44P) terminal No. 4. If the connections are good, substitute a known-good PCM Initial Inspection and Diagnostic Overview, and recheck. If the symptom/indication goes away, replace the original PCM Service and Repair.�
NO -
Repair an open in the wire between the radiator fan relay and the PCM.�
19. Disconnect the jumper wire.
20. Reinstall the radiator fan relay.
21. Disconnect the radiator fan motor 2P connector.
22. Turn the ignition switch to ON (II), then set the A/C button and fan control dial ON.
23. Measure the voltage between radiator fan motor 2P connector terminal No. 2 and body ground.
Is there battery voltage?
YES -
Go to step 24.
NO -
Repair an open in the wire between the radiator fan relay and the radiator fan motor.�
24. Set the A/C button and fan control dial OFF, then turn the ignition switch to LOCK (0).
25. Reconnect the radiator fan motor 2P connector.
26. Connect radiator fan motor 2P connector terminal No. 1 to body ground with a jumper wire.
27. Turn the ignition switch to ON (II), then set the A/C button and fan control dial ON.
Does the radiator fan run?
YES -
Go to step 28.
NO -
Replace the radiator fan motor Service and Repair.�
28. Set the A/C button and fan control dial OFF, then turn the ignition switch to LOCK (0).
29. Disconnect the jumper wire.
30. Remove the fan control relay from the under-hood relay box, and test it Testing and Inspection.
Is the relay OK?
YES -
Go to step 31.
NO -
Replace the fan control relay.�
31. Turn the ignition switch to ON (II), then set the A/C button and fan control dial ON.
32. Measure the voltage between fan control relay 5P socket terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to step 33.
NO -
Repair an open in the wire between the radiator fan motor and the fan control relay.�
33. Set the A/C button and fan control dial OFF, then turn the ignition switch to LOCK (0).
34. Disconnect the A/C condenser fan motor 2P connector.
35. Check for continuity between fan control relay 5P socket terminal No. 4 and A/C condenser fan motor 2P connector terminal No. 2.
Is there continuity?
YES -
Go to step 36.
NO -
Repair an open in the wire between the fan control relay and the A/C condenser fan motor.�
36. Check for continuity between A/C condenser fan motor 2P connector terminal No. 1 and body ground.
Is there continuity?
YES -
Replace the A/C condenser fan motor Service and Repair.�
NO -
Check for an open in the wire between the A/C condenser fan motor and body ground. If the wire is OK, check for poor ground at G301 Connector and Harness Locations.�
37. Turn the ignition switch to LOCK (0).
38. Remove A/C diode A from the under-hood fuse/relay box.
39. Using the diode setting () on a DVOM, check for current flow in both directions between A/C diode A terminals No. 1 and No. 2.
Is there current flow in only one direction?
YES -
Go to step 40.
NO -
Replace A/C diode A.�
40. Turn the ignition switch to ON (II).
41. Measure the voltage between A/C diode A 2P socket terminal No. 2 and body ground.
Is there battery voltage?
YES -
Replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal/Installation.�
NO -
Repair an open in the wire between the No. 36 (10 A) fuse in the under-dash fuse/relay box and A/C diode A.�