A/C Compressor Clutch Circuit Troubleshooting
A/C Compressor Clutch Circuit TroubleshootingNOTE:
- 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 performing symptom troubleshooting, check for powertrain DTCs.
1. Check the No. 59 (7.5 A) fuse in the under-hood fuse/relay box, and the No. 3 (7.5 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. Start the engine, and check the engine coolant temperature, throttle position, and idle speed (use the HDS PGM-FI data list if possible).
Are the coolant temperature, throttle position, and idle speed OK?
YES - Go to step 3.
NO - Troubleshoot and repair the cause of the high engine coolant temperature, low idle, or excessively high throttle position sensor reading.
3. Turn the ignition switch OFF.
4. 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 5.
NO - Replace the A/C compressor clutch relay.
5. 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 6.
NO - Replace the under-hood fuse/relay box.
6. 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 7.
NO - Go to step 19.
7. Disconnect the jumper wire.
8. Turn the ignition switch ON (II).
9. 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 10.
NO - Repair open in the wire between the No. 3 fuse in the driver's under-dash fuse/relay box and the A/C compressor clutch relay.
10. Turn the ignition switch OFF.
11. Reinstall the A/C compressor clutch relay.
12. Make sure the A/C switch is OFF.
13. Disconnect PCM connector A (44P).
14. Connect PCM connector A (44P) terminal No. 14 to body ground with a jumper wire.
15. Turn the ignition switch ON (II).
Does the A/C compressor click?
YES - Go to step 16.
NO - Repair open in the wire between the A/C compressor clutch relay and the PCM.
16. Turn the ignition switch OFF.
17. Reconnect PCM connector A (44P), and turn the ignition switch ON (II).
18. Measure the voltage between the No. 41 terminal of PCM connector A (44P) and body ground.
Is there about 5 V?
YES - Repair open in the wire between the PCM and the heater control panel.
NO - 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, then do the PCM idle learn procedure
19. Disconnect the jumper wire and PCM connector A (44P).
20. Check for continuity between the No. 14 terminal of PCM connector A (44P) and body ground.
Is there continuity?
YES - Short to ground on the red wire. Repair the short.
NO - Go to step 21.
21. Disconnect the A/C compressor clutch 1P connector.
22. Check for continuity between the A/C compressor clutch relay 4P socket terminal No. 2 and the A/C compressor clutch 1P connector terminal No. 1.
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.