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A/C Signal Circuit Troubleshooting

  1. Start the engine.
  2. Turn the blower switch on.
  3. Turn the A/C switch on.
  4. Check the A/C CLUTCH in the DATA LIST with the HDS.

    Does it indicate ON? 

    YES  -Go to step 5.

    NO  -Do the A/C pressure switch circuit troubleshooting (see RADIATOR AND A/C CONDENSER FAN HIGH SPEED CIRCUIT TROUBLESHOOTING ).

  5. Check the A/C system.

    Does the A/C system operate? 

    YES  -The air conditioning system circuit is OK.

    NO  -Go to step 6.

  6. Turn the ignition switch OFF.
  7. Turn the ignition switch ON (II).
  8. Activate the A/C CLUTCH in the INSPECTION MENU with the HDS.

    Is there a clicking noise from the A/C compressor clutch? 

    YES  -Do the A/C system test (see A/C SYSTEM TEST ).

    NO  -Go to step 9.

  9. Momentarily connect under-hood fuse/ relay box 16P connector terminal No. 15 to body ground with a jumper wire several times.
    Fig 1: Connecting Under-Hood Fuse/Relay Box 16P Connector Terminal No
    G05458228Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there a clicking noise from the A/C compressor clutch? 

    YES  -Repair open in the wire between the ECM/PCM (E27) and the A/C clutch relay.

    NO  -Update the ECM/PCM if it does not have the latest software (see UPDATING THE ECM/PCM ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the symptom/ indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).