A/C Compressor Clutch Circuit Troubleshooting
A/C Compressor Clutch Circuit Troubleshooting
NOTE:
- It is normal for the A/C compressor to turn off under certain conditions, such as low idle, high engine coolant temperature, hard acceleration, or high/low refrigerant pressure.
- 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 PGM-FI 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. 16 (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. If the fuse(s) blow again, check for a short in the No. 20 (7.5 A) fuse and/or the No. 16 (7.5 A) fuse circuit(s).
2. Connect the HDS to the DLC.
3. Start the engine.
4. Turn on the A/C.
5. Check the A/C switch in the PGM-FI Data List with the HDS.
Is the A/C switch ON?
YES -
Go to step 6.
NO -
Go to A/C Signal Circuit Troubleshooting A/C Signal Circuit Troubleshooting.
6. 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 7.
NO -
Troubleshoot the value that is not within the specifications.
7. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
8. 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 -
Go to step 9.
NO -
Replace the A/C compressor clutch relay.
9. 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 10.
NO -
Replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.
10. 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 11.
NO -
Go to step 20.
11. Disconnect the jumper wire.
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
13. Measure the voltage between A/C compressor clutch relay 4P socket terminal No. 4 and body ground.
Is there battery voltage?
YES -
Go to step 14.
NO -
Repair an open in the wire between the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box and the A/C compressor clutch relay.
14. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
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 PCM from damage.
17. Disconnect PCM connector A (49P).
18. Connect PCM connector A (49P) terminal No. 13 to body ground with a jumper wire.
19. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
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 Service and Repair.
NO -
Repair an 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 1P connector.
22. Check for continuity between A/C compressor clutch relay 4P socket terminal No. 2 and A/C compressor clutch 1P connector terminal No. 1.
Is there continuity?
YES -
Check the A/C compressor clutch clearance, and the A/C compressor clutch field coil Testing and Inspection. Repair as needed.
NO -
Repair an open in the wire between the A/C compressor clutch relay and the A/C compressor clutch.