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. 3-6 (30 A) fuse in the under-hood fuse/relay, and the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box.
Are the fuse OK?
YES -
Go to step 2.
NO -
Replace the fuse(s), and recheck. If the fuse(s) blows again, check for a short in the No. 3-6 (30 A) fuse and/or the No. 16 (7.5 A) fuse circuits.�
2. Connect the HDS to the DLC.
3. Turn the ignition switch to ON (II).
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 retest. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM Service and Repair.�
6. Turn the ignition switch to LOCK (0).
7. Remove the relay circuit board Under-Hood Fuse/Relay Box Removal And Installation from the under-hood fuse/relay box, and test the radiator fan relay and fan control relay Testing and Inspection.
Are the relay OK?
YES -
Go to step 8.
NO -
Replace the relay circuit board Under-Hood Fuse/Relay Box Removal And Installation.�
8. Reinstall the relay circuit board.
9. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the ECM/PCM from damage.
10. Disconnect ECM/PCM connector A (49P).
11. Turn the ignition switch to ON (II).
12. Measure the voltage between ECM/PCM connector A terminal No. 5 and body ground.
Is there battery voltage?
YES -
Go to step 13.
NO -
Repair an open in the wires between the under-hood fuse/relay box and the ECM/PCM, or between the No. 16 (7.5 A) fuse in driver's under-dash fuse/relay box and the under-hood fuse/relay box. If wires are OK, replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal And Installation.�
13. Turn the ignition switch to LOCK (0).
14. Connect ECM/PCM connector A (49P) terminal No. 5 to body ground with a jumper wire.
15. 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 ECM/PCM connector A (49P) terminal No. 5. If the connections 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 -
Go to step 16.
16. Turn the ignition switch to LOCK (0).
17. Disconnect the jumper wire.
18. Reconnect ECM/PCM connector A (49P).
19. Disconnect the radiator fan motor 2P connector.
20. Turn the ignition switch to ON (II), then set the air conditioning button and fan control dial ON.
21. Measure the voltage between radiator fan motor 2P connector terminal No. 2 and body ground.
Is there battery voltage?
YES -
Go to step 22.
NO -
Repair an open in the wire between the under-hood fuse/relay box and the radiator fan motor. If the wire is OK, replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal And Installation.�
22. Set the air conditioning button and fan control dial OFF, then turn the ignition switch to LOCK (0).
23. Test the radiator fan motor and A/C condenser fan motor Testing and Inspection.
Are the motor OK?
YES -
Go to step 24.
NO -
Replace the faulty fan motor Radiator And A/C Condenser Fan, Motor, And Shroud Removal And Installation.�
24. Disconnect under-hood fuse/relay box connector C (5P).
25. Disconnect the radiator fan motor 2P connector.
26. Check for continuity between under-hood fuse/relay box connector C (5P) terminal No. 3 and radiator fan motor 2P connector terminal No. 1.
Is there continuity?
YES -
Go to step 27.
NO -
Repair an open in the wire between the under-hood fuse/relay box and the radiator fan motor.�
27. Disconnect under-hood fuse/relay box connector B (14P).
28. Disconnect the A/C condenser fan motor 2P connector.
29. Check for continuity between under-hood fuse/relay box connector B (14P) terminal No. 2 and A/C condenser fan motor 2P connector terminal No. 2.
Is there continuity?
YES -
Go to step 30.
NO -
Repair an open in the wire between the under-hood fuse/relay box and the A/C condenser fan motor.�
30. Check for continuity between A/C condenser fan motor 2P connector terminal No. 1 and body ground.
Is there continuity?
YES -
Replace the relay circuit board. Under-Hood Fuse/Relay Box 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 G302.�