A/C Compressor Clutch Circuit Troubleshooting
A/C Compressor Clutch Circuit TroubleshootingNOTE:
- 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. Symptom Related Diagnostic Procedures
- Before doing any symptom troubleshooting, check for powertrain DTCs.
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(s), and recheck.
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 within the specifications.
8. Remove the A/C compressor clutch relay from the under-hood fuse/relay box, and test it.
Is the relay OK?
YES - Go to step 9.
NO - Replace the A/C compressor clutch relay.
9. Measure the voltage between the A/C compressor clutch relay 4P socket No. 1 terminal and body ground.
Is there battery voltage?
YES - Go to step 10.
NO - Replace the under-hood fuse/relay box.
10. Connect the A/C compressor clutch relay 4P socket No. 1 and No. 2 terminals with a jumper wire.
Does the A/C compressor clutch click?
YES - Go to step 11.
NO - Go to step 20.
11. Disconnect the jumper wire.
12. Turn the ignition switch ON (II).
13. Measure the voltage between the A/C compressor clutch relay 4P socket No. 3 terminal and body ground.
Is there battery voltage?
YES - Go to step 14.
NO - Repair 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.
14. Turn the ignition switch to LOCK (0).
15. Reinstall the A/C compressor clutch relay.
16. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
17. Disconnect PCM connector A (44P).
18. Connect the PCM connector A (44P) No. 14 terminal to body ground with a jumper wire.
19. Turn the ignition switch ON (II).
Does the A/C compressor 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.
NO - Repair open in the wire between the A/C compressor clutch relay and the PCM.
20. Disconnect the jumper wire.
21. Disconnect the A/C compressor clutch 3P connector.
22. Check for continuity between the A/C compressor clutch relay 4P socket No. 2 terminal and the A/C compressor clutch 3P connector terminal No. 3.
Is there continuity?
YES - Check the A/C compressor clutch clearance, A/C compressor clutch field coil, and the A/C compressor thermal protector. Repair as needed.
NO - Repair open in the wire between the A/C compressor clutch relay and the A/C compressor clutch.