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. 3-8 (SUB FAN MTR) (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 you 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. 3-8 (30 A) fuse and 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 PCM, Initial Inspection and Diagnostic Overview and retest. If the symptom/indication goes away with a known-good PCM, replace the original PCM. Service and Repair
6. Remove the relay circuit board Under-Hood Fuse/Relay Box Removal and Installation from the under-hood fuse/relay box, and test the A/C condenser fan relay. Testing and Inspection
Is the relay OK?
YES - Go to step 7.
NO - Replace the relay circuit board.
7. Turn the ignition switch to LOCK (0).
8. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the engine/powertrain control module (PCM) from damage.
9. Disconnect PCM connector A (49P).
10. Turn the ignition switch to ON (II).
11. Measure the voltage between PCM connector A No. 4 terminal and body ground.
Is there battery voltage?
YES - Go to step 12.
NO - Repair open in the wires between the under-hood fuse/relay box and the 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
12. Turn the ignition switch to LOCK (0).
13. Connect PCM connector A (49P) No. 4 terminal to body ground with a jumper wire.
14. 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 PCM connector A (49P) No. 4 terminal. 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 - Go to step 15.
15. Turn the ignition switch to LOCK (0).
16. Disconnect the jumper wire.
17. Reconnect PCM connector A (49P).
18. Disconnect the A/C condenser fan 2P connector.
19. Turn the ignition switch to ON (II), then set the A/C button and fan control button ON.
20. Measure the voltage between the A/C condenser fan 2P connector No. 2 terminal and body ground.
Is there battery voltage?
YES - Go to step 21.
NO - Repair open in the wire between the under-hood fuse/relay box and the A/C condenser fan. If the wire is OK, replace the under-hood fuse/relay box. Under-Hood Fuse/Relay Box Removal and Installation
21. Set the A/C button and fan control button OFF, then turn the ignition switch to LOCK (0).
22. Reconnect the A/C condenser fan 2P connector.
23. Connect the A/C condenser fan 2P connector No. 1 terminal to body ground with a jumper wire.
24. Turn the ignition switch to ON (II), then set the A/C button and fan control button ON.
Does the A/C condenser fan run?
YES - Go to step 25.
NO - Replace the A/C condenser fan motor. Service and Repair
25. Set the A/C button and fan control button OFF, then turn the ignition switch to LOCK (0).
26. Disconnect the jumper wire.
27. 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 28.
NO - Replace the relay circuit board.
28. Disconnect the under-hood fuse/relay box connector C (5P).
29. Disconnect the A/C condenser fan 2P connector.
30. Check for continuity between under-hood fuse/relay box connector C (5P) No. 3 terminal and the A/C condenser fan 2P connector No. 1 terminal.
Is there continuity?
YES - Go to step 31.
NO - Repair open in the wire between the under-hood fuse/relay box and the A/C condenser fan.
31. Disconnect under-hood fuse/relay box connector B (14P).
32. Disconnect the radiator fan 2P connector.
33. Check for continuity between under-hood fuse/relay box connector B (14P) No. 2 terminal and the radiator fan 2P connector No. 2 terminal.
Is there continuity?
YES - Go to step 34.
NO - Repair open in the wire between the under-hood fuse/relay box and the radiator fan.
34. Check for continuity between the radiator fan 2P connector No. 1 terminal and body ground.
Is there continuity?
YES - Replace the radiator fan motor. Service and Repair
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 G302.
