A/C Signal Circuit Troubleshooting

Start the engine.
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?
1. YES -Go to step 5.
2. NO -Do the A/C pressure switch circuit troubleshooting (see A/C PRESSURE SWITCH CIRCUIT TROUBLESHOOTING ).
Check the A/C system.
Does the A/C system operate?
1. YES -The air conditioning system circuit is OK.
2. NO -Go to step 6.
Turn the ignition switch OFF.
Turn the ignition switch 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?
1. YES -Do the A/C system test (see A/C SYSTEM TEST ).
2. NO -Go to step 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 15 To Body Ground With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there clicking noise from the A/C compressor clutch?
1. YES -Repair open in the wire between the ECM/PCM (A27) (2004-2005 models), (E27) (2006 model) and the A/C clutch relay.
2. NO -Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/ PCM (see HOW TO TROUBLESHOOT CIRCUITS AT 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 ).