A/C Compressor Clutch Circuit Troubleshooting
A/C Compressor Clutch Circuit TroubleshootingNOTE:
- It is normal for the A/C compressor to turn 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. Heating/Air Conditioning
- Before performing symptom troubleshooting, check for powertrain DTCs.
1. Check the No. 12 (7.5 A) fuse in the under-hood fuse/relay box, and the No. 30 (10 A) fuse in the driver's under-dash fuse/relay box.
Are the fuses OK?
YES - Go to step 2.
NO - Replace the fuse(s), and recheck.
2. Check the engine coolant temperature, and idle speed (use the HDS PGM-FI data list if possible).
Are the engine coolant temperature, and idle speed OK?
YES - Go to step 3.
NO - Troubleshoot and repair the cause of the high engine coolant temperature, or low idle.
3. Remove the compressor clutch relay from the under-hood fuse/relay box, and test it.
Is the relay OK?
YES - Go to step 4.
NO - Replace the A/C compressor clutch relay.
4. Measure the voltage between the No. 1 terminal of the A/C compressor clutch relay 4P socket and body ground.
Is there battery voltage?
YES - Go to step 5.
NO - Replace the under-hood fuse/relay box.
5. Connect the No. 1 and No. 2 terminals of the A/C compressor clutch relay 4P socket with a jumper wire.
Does the A/C compressor clutch click?
YES - Go to step 6.
NO - Go to step 16.
6. Disconnect the jumper wire.
7. Turn the ignition switch ON (II).
8. Measure the voltage between the No. 4 terminal of the A/C compressor clutch relay 4P socket and body ground.
Is there battery voltage?
YES - Go to step 9.
NO - Repair open in the wire between the No. 30 (10 A) fuse in the driver's under-dash fuse/relay box and the A/C compressor clutch relay.
9. Turn the ignition switch OFF.
10. Reinstall the A/C compressor clutch relay.
11. Make sure the A/C button is OFF.
12. Jump the SCS line with the HDS.
13. Disconnect PCM connector A (49P).
NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
14. Connect the PCM connector A (49P) terminal No. 13 to body ground with a jumper wire.
15. Turn the ignition switch ON (II).
Does the A/C compressor click?
YES - Check for loose wires or poor connections at PCM connector A (49P). 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.
16. Disconnect the jumper wire.
17. Disconnect the A/C compressor clutch 1P connector.
18. Check for continuity between the No. 2 terminal of the A/C compressor clutch relay 4P socket and the No. 1 terminal of the A/C compressor clutch 1P connector.
Is there continuity?
YES - Check the A/C compressor clutch clearance, and the compressor clutch field coil.Repair as needed.
NO - Repair open in the wire between the A/C compressor clutch relay and the A/C compressor clutch.