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.
  • 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, R20A3 engine model, K24Z3 engine model.
  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.■
  1. Connect the HDS to the DLC.
  1. 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 .
  1. Start the engine, then turn on the A/C.
  1. 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 .
  1. Using the HDS, confirm the following values in the PGM-FI Data List at idle.
    TP SENSOR
    About 0.5 V
    RPM
    R20A3 engine model (A/T)
    600−700
    R20A3 engine model (M/T)
    630−730
    K24Z3 engine model (A/T)
    750−850
    K24Z3 engine model (M/T)
    700−800
    ECT SENSOR 2
    80−100 °C (176−212 °F)
    A/C SWITCH
    ON
    A/C CLUTCH
    ON
    A/C PRESSURE SENSOR
    196−3,138 kPa (2−32 kgf/cm 3 ) [28−455 psi]

Are all the values within specifications?
YES -
Go to Step 7 .
NO -
Troubleshoot the value that is not within the specifications.■
Is the relay OK?
YES -
Go to Step 8 .
NO -
Replace the A/C compressor clutch relay .■
  1. 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 -
  1. 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 .
  1. Disconnect the jumper wire.
  1. Turn the ignition switch to ON (II).
  1. 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.■
  1. Turn the ignition switch to LOCK (0).
  1. Reinstall the A/C compressor clutch relay.
  1. Jump the SCS line with the HDS.
    NOTE: This step must be done to protect the powertrain control module (ECM/PCM) from damage.
  1. Disconnect ECM/PCM connector A (44P) (R20A3 engine model) or ECM/PCM connector A (49P) (K24Z3 engine model).
  1. Connect the ECM/PCM connector A (44P) No. 14 terminal (R20A3 engine model) or ECM/PCM connector A (49P) No. 15 terminal (K24Z3 engine model) to body ground with a jumper wire.
  1. 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 (44P) (R20A3 engine model) or ECM/PCM connector A (49P) (K24Z3 engine model). If the connections are good, substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away, replace the original ECM/PCM, R20A3 engine model, K24Z3 engine model. ■
NO -
Repair open in the wire between the A/C compressor clutch relay and the ECM/PCM.■
  1. Disconnect the jumper wire.
  1. Disconnect the A/C compressor clutch 3P connector.
  1. Check for continuity between the A/C compressor clutch relay 4P socket No. 2 terminal and the A/C compressor clutch 3P connector No. 2 terminal (R20A3 engine model) or A/C compressor clutch 3P connector No. 3 terminal (K24Z3 engine model).
Is there continuity?
YES -
Check the A/C compressor clutch clearance, A/C compressor clutch field coil, and the A/C compressor thermal protector. Repair as needed.■
NO -
Repair open in the wire between the A/C compressor clutch relay and the A/C compressor clutch.■