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.
- Before performing symptom troubleshooting, check for powertrain DTCs Initial Inspection and Diagnostic Overview.
1. Check the No. 15 (30 A) fuse in the relay block, and the No. 30 (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 fuse(s) blow again, check for a short in the No. 15 (30 A) and No. 30 (10 A) fuse(s) circuit.�
2. Remove the A/C condenser fan relay and fan control relay from the relay block, and test it Power Relay Test.
Are the relay OK?
YES -
Go to step 3.
NO -
Replace the faulty 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, and retest. If the symptom/indication goes away with a known-good PCM, replace the original PCM Service and Repair.�
7. Measure the voltage between A/C condenser fan relay 4P socket terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to step 8.
NO -
Replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.�
8. 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 on low?
YES -
Go to step 9.
NO -
Go to step 18.
9. Disconnect the jumper wire.
10. Turn the ignition switch to ON (II).
11. Measure the voltage between A/C condenser fan relay 4P socket terminal No. 4 and body ground.
Is there battery voltage?
YES -
Go to step 12.
NO -
Go to step 29.
12. Turn the ignition switch to LOCK (0).
13. Reinstall the A/C condenser fan relay.
14. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
15. Disconnect PCM connector A (49P).
16. Connect PCM connector A (49P) terminal No. 4 to body ground with a jumper wire.
17. 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 (49P) terminal No. 4. If the connections are good, substitute a known-good PCM, and recheck. If the symptom/indication goes away, replace the original PCM Service and Repair.�
NO -
Repair an open in the wire between the A/C condenser fan relay and the PCM.�
18. Disconnect the jumper wire.
19. Reinstall the A/C condenser fan relay.
20. Disconnect the A/C condenser fan motor 2P connector.
21. Turn the ignition switch to ON (II), then set the A/C button and fan control button ON.
22. Measure the voltage between A/C condenser fan motor 2P connector terminal No. 2 and body ground.
Is there battery voltage?
YES -
Go to step 23.
NO -
Repair an open in the wire between the A/C condenser fan relay and the A/C condenser fan motor.�
23. Set the A/C button and fan control button OFF, then turn the ignition switch to LOCK (0).
24. Test the radiator fan motor and A/C condenser fan motor Testing and Inspection.
Are the motor OK?
YES -
Go to step 25.
NO -
Replace the faulty fan motor.�
25. Measure the voltage between fan control relay 5P socket terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to step 26.
NO -
Repair an open in the wire between the A/C condenser fan and the fan control relay.�
26. Disconnect the radiator fan motor 2P connector.
27. Check for continuity between fan control relay 5P socket terminal No. 4 and radiator fan motor 2P connector terminal No. 2.
Is there continuity?
YES -
Go to step 28.
NO -
Repair an open in the wire between the fan control relay and the radiator fan.�
28. Check for continuity between radiator fan motor 2P connector terminal No. 1 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.�
29. Turn the ignition switch to LOCK (0).
30. Remove A/C diode A from the relay block.
31. 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 32.
NO -
Replace A/C diode A.�
32. Turn the ignition switch to ON (II).
33. 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 and Installation.�
NO -
Repair an open in the wire between the No. 30 (10 A) fuse in the under-dash fuse/relay box and A/C diode A.�