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. Symptom Related Diagnostic Procedures
- Before doing any symptom troubleshooting, check for PGM-FI DTCs Initial Inspection and Diagnostic Overview. Also check for B-CAN codes Troubleshooting - B-CAN System Diagnosis Test Mode A.
1. Check the No. A21 (7.5 A) fuse in the under-hood fuse/relay box, and the No. B16 (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. A21 (7.5 A) fuse and/or the No. B16 (7.5 A) fuse circuit(s).
2. Connect the HDS to the DLC How to Troubleshoot the Climate Control System.
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 (Climate Control System).
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. Set the air conditioning button and fan control dial to off, then turn the ignition switch to LOCK (0).
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).
13. 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 14.
NO -
Repair an open in the wire between the No. B16 (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).
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. 41 to body ground with a jumper wire.
19. 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 (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.