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 doing symptom troubleshooting, check for PGM-FI DTCs.
1. Check the No. 3-6 (MAIN FAN MTR) (30 A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES -
Go to step 2.
NO -
Replace the fuse, and recheck. If the fuse blows again, check for a short in the No. 3-6 (MAIN FAN MTR) (30 A) fuse circuit.
2. Connect the HDS to the DLC.
3. Start the engine.
4. Turn on the A/C.
5. Check the FAN LOW CTRL in the PGM-FI Data List with the HDS.
Is the FAN LOW CTRL on?
YES -
Go to step 6.
NO -
Substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away, replace the original ECM/PCM Service and Repair.
6. Turn the ignition switch to LOCK (0).
7. 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 8.
NO -
Replace the radiator fan relay.
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 and Installation.
9. Connect radiator fan relay 4P socket terminals No. 1 and No. 2 with a jumper wire.
Do the radiator and A/C condenser 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. 4 and body ground.
Is there battery voltage?
YES -
Go to step 13.
NO -
Go to step 35.
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 ECM/PCM from damage.
16. Disconnect ECM/PCM connector A (49P).
17. Connect ECM/PCM connector A (49P) terminal No. 5 to body ground with a jumper.
18. Turn the ignition switch to ON (II).
Do the A/C condenser and the radiator fans run on low?
YES -
Check for a loose wire or poor connection at ECM/PCM connector A (49P). If connection are good, substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away, replace the original ECM/PCM Service and Repair.
NO -
Repair an open in the wire between the radiator fan relay and the ECM/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 turn on the A/C.
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. Turn off the A/C, then turn the ignition switch to LOCK (0).
25. Test the radiator fan motor Testing and Inspection.
Is the radiator fan motor OK?
YES -
Go to step 26.
NO -
Replace the radiator fan motor Radiator and A/C Condenser Fan, Motor, and Shroud Removal and Installation.
26. Disconnect under-hood fuse/relay box connector B (14P).
27. Check for continuity between under-hood fuse/relay box connector B (14P) terminal No. 11 and radiator fan motor 2P connector terminal No. 1.
Is there continuity?
YES -
Go to step 28.
NO -
Repair an open in the wire between the under-hood fuse/relay box and the radiator fan motor.
28. Reconnect under-hood fuse/relay box connector B (14P) and the radiator fan motor 2P connector.
29. Remove the relay circuit board Under-Hood Fuse/Relay Box Removal and Installation from the under-hood fuse/relay box, and test the fan control relay Testing and Inspection.
Is the relay OK?
YES -
Go to step 30.
NO -
Replace the relay circuit board.
30. Reinstall the relay circuit board.
31. Disconnect the A/C condenser fan motor 2P connector.
32. Turn the ignition switch to ON (II), then turn on the A/C.
33. 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 34.
NO -
Repair an open in the wire between the under-hood fuse/relay box and the A/C condenser fan motor.
34. Check for continuity between the A/C condenser fan motor 2P connector terminal No. 1 and body ground.
Is there continuity?
YES -
Replace the A/C condenser fan motor Radiator and A/C Condenser Fan, Motor, and Shroud Removal and Installation.
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.
35. Measure the voltage between under-hood fuse/relay box connector B (14P) terminal No. 10 and body ground.
Is there battery voltage?
YES -
Repair an open in the wire between under-hood fuse/relay box connector B (14P) terminal No. 10 and the radiator fan relay.
NO -
Replace the relay circuit board Under-Hood Fuse/Relay Box Removal and Installation.