Radiator and A/C Condenser Fan Low Speed Circuit Troubleshooting
Radiator and A/C Condenser Fan Low/Speed Circuit TroubleshootingNOTE:
- Do not use this troubleshooting procedure if the A/C compressor is inoperative. Refer to the symptom troubleshooting index. Heating/Air Conditioning
- Before performing symptom troubleshooting, check for powertrain DTCs.
1. Check the No. 20 (30 A) fuse in the under-hood fuse/relay box, and the No. 30 (7.5 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.
2. Remove the A/C condenser fan relay from the auxiliary under-hood fuse/relay box, and test it.
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. Turn the ignition switch ON (II).
5. Turn on the A/C on the HVAC control unit.
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.
7. Measure the voltage between the A/C condenser fan relay 4P socket terminal No. 1 and body ground.
Is there battery voltage?
YES - Go to step 8.
NO - Repair open in the wire between the No. 20 fuse in the auxiliary under-hood fuse/relay box and the A/C condenser fan relay.
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?
YES - Go to step 9.
NO - Go to step 17.
9. Disconnect the jumper wire.
10. Turn the ignition switch ON (II).
11. Measure the voltage between the 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 35.
12. Turn the ignition switch OFF.
13. Reinstall the A/C condenser fan relay.
14. Disconnect PCM connector A (44P).
15. Connect the PCM connector A (44P) terminal No. 4 to body ground with a jumper wire.
16. Turn the ignition switch ON (II).
Do the A/C condenser and radiator fans run on LO?
YES - Check for loose wires or poor connections at PCM connector A (44P) terminal No. 4. W the connections are good, substitute a known-good PCM, and recheck. If the symptom/indication goes away, replace the original PCM, then do the PCM idle learn procedure.
NO - Repair open in the wire between the A/C condenser fan relay and the PCM.
17. Disconnect the jumper wire.
18. Reinstall the A/C condenser fan relay.
19. Disconnect the A/C condenser fan 2P connector.
20. Turn the ignition switch ON (II), then set the A/C button and fan control dial ON.
21. Measure the voltage between the A/C condenser fan 2P connector terminal No. 2 and body ground.
Is there battery voltage?
YES - Go to step 22.
NO - Repair open in the wire between the A/C condenser fan relay and the A/C condenser fan.
22. Set the A/C button and fan control dial OFF, then turn the ignition switch OFF.
23. Reconnect the A/C condenser fan 2P connector.
24. Connect the A/C condenser fan 2P connector terminal No. 1 to body ground with a jumper wire.
25. Turn the ignition switch ON (II), then set the A/C button and fan control dial ON.
Does the A/C condenser fan run?
YES - Go to step 26.
NO - Replace the A/C condenser fan motor.
26. Set the A/C button and fan control dial OFF, then turn the ignition switch OFF.
27. Disconnect the jumper wire.
28. Remove the fan control relay from the auxiliary under-hood relay box, and test it.
Is the relay OK?
YES - Go to step 29.
NO - Replace the fan control relay.
29. Turn the ignition switch ON (II), then set the A/C button and fan control dial ON.
30. Measure the voltage between the fan control relay 5P socket terminal No. 1 and body ground.
Is there battery voltage?
YES - Go to step 31.
NO - Repair open in the wire between the A/C condenser fan and the fan control relay.
31. Set the A/C button and fan control dial OFF, then turn the ignition switch OFF.
32. Disconnect the radiator fan 2P connector.
33. Check for continuity between the fan control relay 5P socket terminal No. 4 and the radiator fan 2P connector terminal No. 2.
Is there continuity?
YES - Go to step 34.
NO - Repair open in the wire between the fan control relay and the radiator fan.
34. Check for continuity between the radiator fan 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 G201.
35. Turn the ignition switch OFF.
36. Remove A/C diode A from right engine compartment wire harness.
37. Using the diode setting on a DVOM, check for current flow in both directions between the A/C diode A terminals No. 1 and No. 2.
Is there current flow in only one direction?
YES - Go to step 38.
NO - Replace A/C diode A.
38. Turn the ignition switch ON (II).
39. Measure the voltage between the A/C diode 4P socket terminal No. 2 and body ground.
Is there battery voltage?
YES - Repair open in the wire between A/C diode A and the A/C condenser fan relay.
NO - Repair open in the wire between the No. 30 fuse in the under-dash fuse/relay box and A/C diode A.