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, or hard acceleration.
- Do not use this troubleshooting procedure if the fans are also inoperative with the A/C on. Refer to the symptom troubleshooting index - Refer to: Heating and A/C Systems Symptom Troubleshooting Index(Heating/Air Conditioning) Climate Control System Symptom Troubleshooting Index(Climate Control) .
- Before doing symptom troubleshooting, check for PGM-FI DTCs - Refer to: How to Troubleshoot the Fuel and Emissions SystemsHow to Troubleshoot the CVT System(CVT System) .
- 1. HVAC control system check:
- 1. Connect the HDS to the DLC.
- 2. Start the engine.
- 3. Set the A/C button and the blower control dial to ON.
- 4. Check the parameter(s) below with the HDS.
Signal Threshold Current conditions Values Unit Values Unit A/C SWITCH ON A/C CLUTCH ON Do the current condition(s) match the threshold?
YES
Go to step 2.
NO
A/C SWITCH is OFF, go to the A/C signal circuit troubleshooting - Refer to: A/C Signal Circuit Troubleshooting(Idle Control System)A/C Signal Circuit Troubleshooting(Heating/Air Conditioning) A/C Signal Circuit Troubleshooting(Climate Control) .
NO
A/C SWITCH is ON and A/C CLUTCH is OFF, update the PCM if it does not have the latest software, or substitute a known-good PCM , and recheck.
- 2. Fuse check:
- 1. Check the following fuse.
Fuse No. A27 (7.5 A) Location Under-hood fuse/relay box Is the fuse OK?
YES
Go to step 3.
NO
Replace the fuse, and recheck. If the fuse blows again, repair a short in the No. A27 (7.5 A) fuse circuit.
- 3. A/C compressor clutch relay check:
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. 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 4.
NO
Replace the A/C compressor clutch relay.
- 4. Open wire check (+B MG CLUTCH line):
- 1. Measure the voltage between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode A/C compressor clutch relay: disconnected Test point 1 A/C compressor clutch relay 4P socket No. 1 Test point 2 Body ground Is there battery voltage?
YES
The +B MG CLUTCH wire is OK. Go to step 5.
NO
Repair an open in the wire between the No. A27 (7.5 A) fuse in the under-hood fuse/relay box and the A/C compressor clutch relay.
- 5. Determine possible failure area (A/C compressor clutch relay switch side circuit, A/C compressor clutch relay coil side circuit):
- 1. Connect terminals A and B with a jumper wire.
Terminal A A/C compressor clutch relay 4P socket No. 1 Terminal B A/C compressor clutch relay 4P socket No. 2 Does the A/C compressor clutch click?
YES
Go to step 6.
NO
Go to step 8.
- 6. Open wire check (IG2 A/C line):
- 1. Disconnect the jumper wire.
- 2. Turn the vehicle to the ON mode.
- 3. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode A/C compressor clutch relay: disconnected Test point 1 A/C compressor clutch relay 4P socket No. 7 Test point 2 Body ground Is there battery voltage?
YES
The IG2 A/C wire is OK. Go to step 7.
NO
Repair an open in the wire between the No. B22 (7.5 A) fuse in the under-dash fuse/relay box and the A/C compressor clutch relay in under-hood fuse/relay box.
- 7. Open wire check (A/C MG CLUTCH RLY CL- line):
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Reinstall the A/C compressor clutch relay.
- 3. Jump the SCS line with the HDS, and wait more than 1 minute.
NOTE: This step must be done to protect the PCM from damage.
- 4. Disconnect the following connector.
PCM connector A (51P) - 5. Connect terminals A and B with a jumper wire.
Terminal A PCM connector A (51P) terminal No. 13 Terminal B Body ground - 6. Turn the vehicle to the ON mode.
Does the A/C compressor clutch click?
YES
Update the PCM if it does not have the latest software, or substitute a known-good PCM , and recheck.
NO
Repair an open in the wire between the A/C compressor clutch relay and the PCM.
- 8. Open wire check (A/C MG CLUTCH line):
- 1. Disconnect the jumper wire.
- 2. Disconnect the following connector.
A/C compressor clutch 3P connector - 3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode A/C compressor clutch relay: disconnected A/C compressor clutch 3P connector: disconnected Test point 1 A/C compressor clutch relay 4P socket No. 2 Test point 2 A/C compressor clutch 3P connector No. 1 Is there continuity?
YES
The A/C MG CLUTCH wire is OK. Check the A/C compressor clutch clearance and the A/C compressor clutch field coil . Repair as needed.
NO
Repair an open in the wire between the A/C compressor clutch relay and the A/C compressor clutch.
