A/C Signal Circuit Troubleshooting
- Start the engine, and let it idle.
- Turn the blower switch on.
- Turn the A/C switch on.
- Check the A/C CLUTCH in the DATA LIST with the HDS.
Does it indicate ON?
YES: Go to step 5.
NO: Do A/C SYSTEM TEST .
- Check the A/C system.
Does the A/C system operate?
YES: The A/C signal circuit is OK.
NO: Go to step 6.
- Turn the ignition switch to LOCK (0).
- Turn the ignition switch to ON (II).
- 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 A/C SYSTEM TEST .
NO: Go to step 9.
- Turn the ignition switch to LOCK (0).
- Jump the SCS line with the HDS.
- Disconnect ECM/PCM connector A (49P).
- Turn the ignition switch to ON (II).
- Momentarily connect ECM/PCM connector terminal A15 to body ground with a jumper wire several times.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there a clicking noise from the A/C compressor clutch?
YES: Update the ECM/PCM if it does not have the latest software (see ECM/PCM UPDATE ), 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 ).
NO: Check for poor connections or loose terminals at the A/C compressor clutch relay and the ECM/PCM. If the connections and the terminals are OK, check the A/C compressor clutch relay (see POWER RELAY TEST ). If needed, repair open in the wire between the ECM/PCM (A15) and the A/C compressor clutch relay, or in other A/C parts.