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 powertrain DTCs Initial Inspection and Diagnostic Overview.

1. Check the No. 1 (30 A) fuse in the under-hood fuse/relay box, and the No. 14 (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. If either fuse blows again, check for a short in the No. 1 (30 A) or No. 14 (10 A) fuse circuits.�

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 pressure switch circuit troubleshooting A/C Pressure Switch 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).

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 A/C compressor clutch relay 4P socket terminal No. 2 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 19.

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 BLK/YEL wire between the No. 14 (10 A) fuse in the under-dash fuse/relay box and the A/C compressor clutch relay socket.�

14. Turn the ignition switch to LOCK (0).

15. Reinstall the A/C compressor clutch relay.

16. Make sure the A/C button is OFF.

17. Turn the ignition switch to ON (II).

18. Measure the voltage between ECM/PCM connector E (31P) terminal No. 18 and body ground with the ECM/PCM connectors connected.





Is there battery voltage?

YES -

Check for loose wires or poor connections at ECM/PCM connector E (31P). If the connections are good, substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away, replace the original ECM/PCM ECM/PCM Replacement (A/T).�

NO -

Repair an open in the wire between the A/C compressor clutch relay and the ECM/PCM.�

19. Disconnect the jumper wire.

20. Disconnect the A/C compressor clutch 1P connector.

21. Check for continuity between A/C compressor clutch relay 4P socket terminal No. 1 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.�

NO -

Repair an open in the wire between the A/C compressor clutch relay socket and the A/C compressor clutch.�