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 Initial Inspection and Diagnostic Overview.

1. Check the No. B30 (30 A) fuse in the under-hood fuse/relay box, and the No. C26 (7.5 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. If the fuse(s) blow again, check for a short in the No. B30 (30 A) fuse and/or the No. C26 (7.5 A) fuse circuit(s).

2. Remove the A/C condenser 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 A/C condenser fan relay.

3. Connect the HDS to the DLC.

4. Start the engine.

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 recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM Service and Repair.

7. Set the air conditioning button and the fan control dial OFF, then turn the ignition switch to LOCK (0).

8. 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 9.

NO -

Replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.

9. Connect A/C condenser fan relay 4P socket terminals No. 1 and No. 2 with a jumper wire.





Does the A/C condenser fan and the radiator fan 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 A/C condenser fan relay 4P socket terminal No. 3 and body ground.





Is there battery voltage?

YES -

Go to step 13.

NO -

Go to step 34.

13. Turn the ignition switch to LOCK (0).

14. Reinstall the A/C condenser fan relay.

15. Jump the SCS line with the HDS.

NOTE: This step must be done to protect the PCM from damage.

16. Disconnect PCM connector A (49P).

17. Connect PCM connector A (49P) terminal No. 4 to body ground with a jumper wire.






18. Turn the ignition switch to ON (II).

Does the A/C condenser fan and the radiator fan run on low?

YES -

Check for loose wires or poor connections at PCM connector A (49P). 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.

19. Disconnect the jumper wire.

20. Reinstall the A/C condenser fan relay.

21. Disconnect the A/C condenser fan motor 2P connector.

22. Turn the ignition switch to ON (II), then set the air conditioning button and the fan control dial to ON.

23. Measure the voltage between A/C condenser fan motor 2P connector terminal No. 1 and body ground.





Is there battery voltage?

YES -

Go to step 24.

NO -

Repair an open in the wire between the A/C condenser fan relay and the A/C condenser fan motor.

24. Set the air conditioning button and the fan control dial OFF, then turn the ignition switch to LOCK (0).

25. Test the A/C condenser fan motor Testing and Inspection.

Is the A/C condenser fan motor OK?

YES -

Go to step 26.

NO -

Replace the A/C condenser fan motor Radiator And A/C Condenser Fan, Motor, And Shroud Removal And Installation.

26. Reconnect the A/C condenser fan motor 2P connector.

27. Remove the fan control relay from the under-hood fuse/relay box, and test it Testing and Inspection.

Is the relay OK?

YES -

Go to step 28.

NO -

Replace the fan control relay.

28. Turn the ignition switch to ON (II), then set the air conditioning button and the fan control button ON.

29. Measure the voltage between fan control relay 5P socket terminal No. 1 and body ground.





Is there battery voltage?

YES -

Go to step 30.

NO -

Repair an open in the wire between the A/C condenser fan motor and the fan control relay.

30. Set the air conditioning button and the fan control dial OFF, then turn the ignition switch to LOCK (0).

31. Disconnect the radiator fan motor 2P connector.

32. Check for continuity between fan control relay 5P socket terminal No. 4 and radiator fan motor 2P connector terminal No. 1.





Is there continuity?

YES -

Go to step 33.

NO -

Repair an open in the wire between the fan control relay and the radiator fan motor.

33. Check for continuity between radiator fan motor 2P connector terminal No. 2 and body ground.





Is there continuity?

YES -

Replace the radiator fan motor Radiator And A/C Condenser Fan, Motor, And Shroud Removal And Installation.

NO -

Check for an open in the wire between the radiator fan motor and body ground. If the wire is OK, check for poor ground at G201.

34. Turn the ignition switch to LOCK (0).

35. Remove A/C diode A from the under-hood fuse/relay box.

36. 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 37.

NO -

Replace A/C diode A.

37. Turn the ignition switch to ON (II).

38. 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. C26 (7.5 A) fuse in the under-dash fuse/relay box and A/C diode A.