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 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 14P connector terminal No. 10 to body ground with a jumper wire several times.

Fig 1: Connecting Under-Hood Fuse/Relay Box 14P Connector Terminal To Body Ground With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there a clicking noise from the A/C compressor clutch?
1. YES - Repair open in the wire between the ECM/PCM (E18) and the A/C clutch relay.
2. NO - ECM/PCM UPDATING AND SUBSTITUTION FOR TESTING ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).