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.
Is it ON?
1. YES - Go to step 5.
2. NO - Go to 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 A/C SYSTEM INSPECTION .
2. NO - Go to step 9.
Momentarily connect under-hood fuse/relay box 16P connector terminal No. 11 to body ground with a jumper wire several times.
Is there clicking noise from the A/C compressor clutch?
1. YES - Repair open in the wire between the ECM (E18) and the A/C clutch relay.
2. NO - Update the ECM if it does not have the latest software, or substitute a known-good ECM (see UPDATING THE ECM ), then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM (see ECM REPLACEMENT ).
  
  Fig 1: Connecting Under-Hood Fuse/Relay Box 16P Connector Terminal No. 11 To Body Ground With Jumper Wire
  Courtesy of AMERICAN HONDA MOTOR CO., INC.