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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  - Go to the A/C pressure switch test circuit troubleshooting (see A/C PRESSURE SWITCH 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. Turn the ignition switch OFF.
  10. Jump the SCS line with the HDS.
  11. Disconnect PCM connector A (44P).
  12. Turn the ignition switch ON (II).
  13. Momentarily connect PCM connector Terminal A14 to body ground with a jumper wire several times.
    Fig 1: Connecting PCM Connector Terminal A14 To Body Ground With Jumper Wire
    G04546129Courtesy of AMERICAN HONDA MOTOR CO., INC.

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

    YES  - Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck (see PCM UPDATING AND SUBSTITUTION FOR TESTING ). If the symptom/indication goes away with a known-good PCM, replace the original PCM. The air conditioning signal OK.

    NO  - Check for poor connections or loose terminals at the A/C clutch relay and PCM. If they are OK, check for the A/C clutch relay (see POWER RELAY TEST ), and other A/C systems.