Honda Accord: A/C Signal Circuit Troubleshooting

1. Start the engine, and let it idle.

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 HDS.

Does it indicate ON? YES

-Go to step 5.

NO

-Do the A/C system test (see page 21-89).

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 to LOCK (0).

7. Turn the ignition switch to ON (II).

8. 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 the A/C system test (see page 21-89).

NO-

Go to step 9.

9. Turn the ignition switch to LOCK (0).

10. Jump the SCS line with the HDS.

11. Disconnect ECM/PCM connector A (49P).

12. Turn the ignition switch to ON (II).

13. Momentarily connect ECM/PCM connector terminal A15 to body ground with a jumper wire several times.

ECM/PCM CONNECTOR A (49P)

Terminal side of female terminals

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 page 11-203), or substitute a known-good ECM/PCM (see page 11-7), then recheck.

If the symptom/indication goes away and the ECM/PCM was updated, troubleshooting is complete.

If the symptom/indication goes away and the ECM/PCM was substituted, replace the original ECM/PCM (see page 11-204).

NO

-Check for poor connections or loose terminals at the A/C compressor clutch relay and the ECM/PCM. If the connections are OK, check the A/C compressor clutch relay (see page 22-93). If needed, repair open in the wire between the ECM/PCM (A15), the A/C compressor clutch relay, or other parts in the A/C systems.