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 pressure.
- If the blower motor does not run at all speeds, the A/C compressor will be inoperative. Run the self-diagnostic function, and check the DTC B1241. Before performing any other troubleshooting, repair the cause of the inoperative blower motor.
- 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. 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 the No. 16 (7.5 A) fuse circuits.
2. Connect the HDS to the DLC.
3. Check for these PGM-FI DTCs: P0117, P0118, P0506, P0507, P0532, and P0533.
Are any of these DTCs indicated?
YES - Go to the appropriate troubleshooting section.
NO - Go to step 4.
4. Start the engine, then turn on the A/C.
5. Check the A/C CLUTCH in the PGM-FI Data List with the HDS.
Is the A/C CLUTCH on?
YES - Go to step 7.
NO - Go to step 6.
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. 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 8.
NO - Replace the A/C compressor clutch relay.
8. Measure the voltage between the A/C compressor clutch relay 4P socket terminal No. 1 and body ground.
Is there battery voltage?
YES - Go to step 9.
NO - Replace the under-hood fuse/relay box. Under-Hood Fuse/Relay Box Removal and Installation
9. Connect the 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 10.
NO - Go to step 19.
10. Disconnect the jumper wire.
11. Turn the ignition switch to ON (II).
12. Measure the voltage between the A/C compressor clutch relay 4P socket terminal No. 4 and body ground.
Is there battery voltage?
YES - Go to step 13.
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. If the wire is OK, replace the under-hood fuse/relay box.
13. Turn the ignition switch to LOCK (0).
14. Reinstall the A/C compressor clutch relay.
15. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the engine control module/powertrain control module (ECM/PCM) from damage.
16. Disconnect ECM/PCM connector A (49P).
17. Connect the ECM/PCM connector A (49P) terminal No. 15 to body ground with a jumper wire.
18. Turn the ignition switch to ON (II).
Does the A/C compressor click?
YES - Check for loose wires or poor connections at ECM/PCM connector A (49P). 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 3P connector.
21. Check for continuity between the A/C compressor clutch relay 4P socket terminal No. 2 and the A/C compressor clutch 3P connector terminal No. 3.
Is there continuity?
YES - Check the A/C compressor clutch clearance, A/C compressor clutch field coil, and the A/C compressor thermal protector. Service and Repair Repair as needed.
NO - Repair an open in the wire between the A/C compressor clutch relay and the A/C compressor clutch.
