A/C Compressor Clutch Circuit Troubleshooting
- 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.
- 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 (see GENERAL TROUBLESHOOTING INFORMATION ).
- Check the No. 17 (7.5 A) fuse in the relay block, and the No. 30 (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 the fuse(s) blow again, check for a short in the No. 17 (7.5 A) and No. 30 (10 A)fuse(s) circuit.
- Connect the HDS to the DLC.
- Start the engine.
- Turn on the A/C.
- 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.
- Using the HDS, confirm the following values in the PGM-FI Data List at idle.A/C SWITCH REFERENCE CHART
A/C SWITCH ON A/C PRESSURE SENSOR 196-3, 138 kPa (2-32 kgf/cm2 ) [28-455 psi] Are all the values within specifications?
YES - Go to step 7.
NO - Troubleshoot the value that is not within the specifications.
- Remove the A/C compressor clutch relay from the relay block, and test it (see
POWER RELAY TEST
).
Is the relay OK?
YES - Go to step 8.
NO - Replace the A/C compressor clutch relay.
- Measure the voltage between the A/C compressor clutch relay 4P socket No. 1 terminal and body ground.Fig 1: Measuring Voltage Between A/C Compressor Clutch Relay 4P Socket No. 1 Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES - Go to step 9.
NO - Replace the relay block (see REMOVAL AND INSTALLATION ).
- Connect the A/C compressor clutch relay 4P socket No. 1 and No. 2 terminals with a jumper wire.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Does the A/C compressor clutch click?
YES - Go to step 10.
NO - Go to step 19.
- Disconnect the jumper wire.
- Turn the ignition switch to ON (II).
- Measure the voltage between the A/C compressor clutch relay 4P socket No. 4 terminal and body ground.Fig 3: Measuring Voltage Between A/C Compressor Clutch Relay 4P Socket No. 4 Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES - Go to step 13.
NO - Repair open in the wire between the No. 30 (10 A) fuse in the under-dash fuse/relay box and the A/C compressor clutch relay.
- Turn the ignition switch to LOCK (0).
- Reinstall the A/C compressor clutch relay.
- Jump the SCS line with the HDS.NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
- Disconnect PCM connector A (49P).
- Connect PCM connector A (49P) No. 13 terminal to body ground with a jumper wire.
- Turn the ignition switch to ON (II).
Does the A/C compressor 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 (see PCM REPLACEMENT ).
NO - Repair open in the wire between the A/C compressor clutch relay and the PCM.
- Disconnect the jumper wire.
- Disconnect the A/C compressor clutch 1P connector.
- 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.Fig 5: Identifying Continuity Between A/C Compressor Clutch Relay 4P Socket No. 2 And No. 1 Terminal
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Check the A/C compressor clutch clearance, and the compressor clutch field coil (see A/C COMPRESSOR CLUTCH CHECK ). Repair as needed.
NO - Repair open in the wire between the A/C compressor clutch relay and the A/C compressor clutch.