Operation CHARM: Car repair manuals for everyone.

A/C Signal Circuit Troubleshooting

A/C Signal Circuit Troubleshooting

1. Start the engine.
2. Turn the blower switch ON.
3. Turn the A/C switch ON.
4. Check the A/C CLUTCH in the DATA LIST with the Honda PGM Tester or the HDS.

Is it ON?

YES - Go to step 5.

NO - Go to the A/C pressure switch test.

5. Check the A/C system.

Does the A/C system operate?

YES - The air conditioning system circuit is OK.

NO - Go to step 6.

6. Turn the ignition switch OFF.
7. Turn the ignition switch ON (II).
8. Activate the A/C CLUTCH in the INSPECTION MENU with the Honda PGM Tester or the HDS. Is there a clicking noise from the A/C compressor clutch?

YES - Go to the A/C Section, and lock for the other symptoms.

NO - Go to step 9.




9. Momentarily connect under-hood fuse/relay box 14P connector terminal No.10 to body ground with a jumper wire several times.

Is there clicking noise from the A/C compressor clutch?

YES - Repair open in the wire between the ECM/PCM (E18) and the A/C clutch relay

NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM replace the original ECM/PCM.