A/C Compressor Clutch Circuit Troubleshooting
A/C Compressor Clutch Circuit Troubleshooting
NOTE:
- The PCM can turn the A/C compressor OFF under certain conditions, such as low idle, high engine coolant temperature, or hard acceleration.
- Do not use this troubleshooting procedure if the fans are also inoperative with the A/C on. Refer to the symptom troubleshooting index.
- Before doing any symptom troubleshooting, check for powertrain DTCs Initial Inspection and Diagnostic Overview.
1. Check the No. 20 (7.5 A) fuse in the under-hood fuse/relay box, and the No. 36 (10 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 blows again, check for a short in the No. 20 (7.5 A) and the No. 36 (10 A) fuses circuit.
2. Connect the HDS to the DLC.
3. Check for these PGM-FI DTCs: P0117, P0118, P0506, P0507, P0532, and P0533.
Are any of these DTCs indicated?
YES -
Go to the appropriate troubleshooting section.
NO -
Go to step 4.
4. Start the engine.
5. Turn on the A/C.
6. Check the A/C CLUTCH in the PGM-FI Data List with the HDS.
Is the A/C CLUTCH on?
YES -
Go to step 8.
NO -
Go to step 7.
7. Using the HDS, confirm the following values in the PGM-FI Data List at idle.
Are all the values within specifications?
YES -
Go to step 8.
NO -
Troubleshoot the value that is not with in the specifications.
8. Turn the ignition switch to LOCK (0).
9. Remove the A/C compressor clutch relay from the under-hood fuse/relay box, and test it Testing and Inspection.
Is the relay OK?
YES -
With the A/C compressor clutch relay disconnected, go to step 10.
NO -
Replace the A/C compressor clutch relay.
10. Measure the voltage between A/C compressor clutch relay 4P socket terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to step 11.
NO -
Replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.
11. Connect A/C compressor clutch relay 4P socket terminals No. 1 and No. 2 with a jumper wire.
Does the A/C compressor clutch click?
YES -
Go to step 12.
NO -
Go to step 21.
12. Disconnect the jumper wire.
13. Turn the ignition switch to ON (II).
14. Measure the voltage between A/C compressor clutch relay 4P socket terminal No. 3 and body ground.
Is there battery voltage?
YES -
Go to step 15.
NO -
Repair an open in the wire between the No. 36 (10 A) fuse in the under-dash fuse/relay box and the A/C compressor clutch relay.
15. Turn the ignition switch to LOCK (0).
16. Reinstall the A/C compressor clutch relay.
17. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
18. Disconnect PCM connector A (44P).
19. Connect PCM connector A (44P) terminal No. 14 to body ground with a jumper wire.
20. Turn the ignition switch to ON (II).
Does the A/C compressor clutch click?
YES -
Check for loose wires or poor connections at PCM connector A (44P). If the connections are good, check the PCM grounds. If the grounds 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 compressor clutch relay and the PCM.
21. Disconnect the jumper wire.
22. Disconnect the A/C compressor clutch 3P connector.
23. Check for continuity between A/C compressor clutch relay 4P socket terminal No. 2 and A/C compressor clutch 3P connector terminal No. 3.
Is there continuity?
YES -
Check the A/C compressor clutch clearance and the A/C compressor clutch field coil. Repair as needed Testing and Inspection.
NO -
Repair an open in the wire between the A/C compressor clutch relay and the A/C compressor clutch.