A/C Signal Circuit Troubleshooting

WARNING: This page is about a different car, the 2012 Honda Fit, 2011 Honda Fit, 2010 Honda Fit, and 2009 Honda Fit. However, it is still accessible from the selected car via links, so may be relevant.

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.

Fig 1: Connecting ECM/PCM Connector Terminal A15 To Body Ground With Jumper Wire
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.