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 Also check for B-CAN codes. Troubleshooting - B-CAN System Diagnosis Test Mode A
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. 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 (Without Climate Control)
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 No. 1 terminal 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 No. 1 and No. 2 terminals 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 No. 4 terminal and body ground.
Is there battery voltage?
YES - Go to step 13.
NO - Repair 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.
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 (ECM)/powertrain control module (PCM) from damage.
16. Disconnect ECM/PCM connector A (49P).
17. Connect the ECM/PCM connector A (49P) No. 15 terminal 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, check the ECM/PCM grounds. If the grounds are good, substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away, replace the original ECM/PCM. Service and Repair
NO - Repair 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 the A/C compressor clutch relay 4P socket No. 2 terminal and the A/C compressor clutch 1P connector No. 1 terminal.
Is there continuity?
YES - Check the A/C compressor clutch clearance, and the compressor clutch field coil. Testing and Inspection Repair as needed.
NO - Repair open in the wire between the A/C compressor clutch relay and the A/C compressor clutch.
