A/C Condenser Fan High Speed Circuit Troubleshooting
A/C Condenser Fan High 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. 6 (20 A) and No. 15 (7.5 A) fuses in the under-hood fuse/relay box.
Are the fuses OK?
YES - Go to step 2.
NO - Replace the fuses, and recheck. If the fuses blow again, check for a short in the No. 6 (20 A) and No. 15 (7.5 A) fuses circuit.
2. Remove the A/C condenser fan relay from the 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. Measure the voltage between the A/C condenser fan relay 4P socket No. 1 terminal and body ground.
Is there battery voltage?
YES - Go to step 4.
NO - Replace the under-hood fuse/relay box.
4. Connect the A/C condenser fan relay 4P socket No. 1 and No. 2 terminals with a jumper wire.
Does the A/C condenser fan run on high?
YES - Go to step 5.
NO - Replace the under-hood fuse/relay box.
5. Disconnect the jumper wire.
6. Turn the ignition switch to ON (II).
7. Measure the voltage between the A/C condenser fan relay 4P socket No. 4 terminal and body ground.
Is there battery voltage?
YES - Go to step 8.
NO - Go to step 15.
8. Turn the ignition switch to LOCK (0).
9. Check for continuity between the fan control relay 5P socket No. 2 terminal and body ground.
Is there continuity?
YES - Go to step 10.
NO - Check for an open in the wire between the fan control relay and body ground. If the wire is OK, check for poor ground at G301.
10. Reinstall the A/C condenser fan relay.
11. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the engine control module (ECM)/powertrain control module (PCM) from damage.
12. Disconnect ECM/PCM connector A (44P).
13. Connect the ECM/PCM connector A (44P) No. 5 terminal to body ground with a jumper wire.
14. Turn the ignition switch to ON (II).
Does the A/C condenser fan run on high?
YES - Check for loose wires or poor connections at ECM/PCM connector A (44P) No. 5 terminal. If the connections are good, substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away, replace the original ECM/PCM.
NO - Repair open in the wire between the A/C condenser fan relay and the ECM/PCM.
15. Turn the ignition switch to LOCK (0).
16. Remove A/C diode B from the under-hood fuse/relay box.
17. Turn the ignition switch to ON (II).
18. Measure the voltage between the A/C diode B 2P socket No. 2 terminal and body ground.
Is there battery voltage?
YES - Go to step 19.
NO - Replace the under-hood fuse/relay box.
19. Using the diode setting on a DVOM, check for current flow in both directions between the A/C diode B No. 1 and No. 2 terminals.
Is there current flow in only one direction?
YES - Replace the under-hood fuse/relay box.
NO - Replace A/C diode B.