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 powertrain DTCs.
1. Check the No. B10 (7.5 A) and the No. B30 (30 A) fuse in the under-dash fuse/relay box.
Are the fuses OK?
YES -
Go to step 2.
NO -
Replace the fuse, and recheck. If the fuse blow again, check for a short in the No.B10 (7.5 A) fuse and the No. B30 (30 A) fuse circuits.
2. Remove the radiator fan relay from auxiliary under-hood relay box B, 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 ECM/PCM, and recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM Service and Repair.
7. Turn the A/C switch and the fan control switch OFF, then 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-dash fuse/relay box.
- USA models Under-Dash Fuse/Relay Box Removal and Installation (USA Models)
- Canada models Under-Dash Fuse/Relay Box Removal and Installation (Canada Models)
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?
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. 7 and body ground.
Is there battery voltage?
YES -
Go to step 13.
NO -
Repair an open in the wire between the No. B10 (7.5 A) fuse in the under-dash fuse/relay box, A/C diode B, and the radiator fan relay.
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 (44P).
17. Connect ECM/PCM connector A (44P) terminal No. 4 to body ground with a jumper wire.
18. Turn the ignition switch to ON (II).
Do the radiator and A/C condenser fans run on LO?
YES -
Check for loose wires or poor connection at ECM/PCM connector A (44P). If the connection is good, substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away, replace the original ECM/PCM Service and Repair, then do the ECM/PCM idle learn procedure ECM/PCM Idle Learn Procedure.
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 2P connector.
22. Turn the ignition switch to ON (II), then turn the A/C switch and the fan control switch ON.
23. Measure the voltage between radiator fan 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 radiator fan relay and the radiator fan.
24. Turn the A/C switch and the fan control switch OFF, then turn the ignition switch to LOCK (0).
25. Remove the fan control relay from auxiliary under-hood relay box A, and test it Testing and Inspection.
Is the relay OK?
YES -
Go to step 26.
NO -
Replace the fan control relay.
26. Check for continuity between radiator fan 2P connector terminal No. 2 and fan control relay 5P socket terminal No. 6.
Is there continuity?
YES -
Go to step 27.
NO -
Repair an open in the wire between the radiator fan and the fan control relay.
27. Remove the radiator fan relay.
28. Connect radiator fan relay 4P socket terminal No. 1 and No. 2 with a jumper wire.
29. Connect fan control relay 5P socket terminal No. 6 to body ground with a jumper wire.
Do the radiator fan run on high?
YES -
Go to step 30.
NO -
Replace the radiator fan motor Radiator And A/C Condenser Fan, Motor, And Shroud Removal And Installation.
30. Disconnect the jumper wires.
31. Disconnect the A/C condenser fan 2P connector.
32. Check for continuity between fan control relay 5P socket terminal No. 14 and A/C condenser fan 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 A/C condenser fan.
33. Check for continuity between A/C condenser fan 2P connector terminal No. 2 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 and body ground. If the wire is OK, check for poor ground at G401.