A/C Signal Circuit Troubleshooting(Idle Control System)

A/C compressor clutch condition check:
- 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 2.

NO

Do the A/C system test - Refer to: A/C System Test, or A/C System Inspection .
A/C system check:
Check the A/C system.

Does the A/C system operate?

YES

The A/C signal circuit is OK.

NO

Go to step 3.
A/C compressor clutch circuit check:
- 1. Turn the ignition switch to LOCK (0).

- 2. Turn the ignition switch to ON (II).

- 3. Activate the A/C CLUTCH in the INSPECTION MENU with the HDS.

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

YES

A/C compressor clutch circuit is OK. Do the A/C system test - Refer to: A/C System Test, or A/C System Inspection .

NO

Go to step 4.

Open wire check (A/C_MG_CLUTCH_RLY_CL- line):

- 1. Turn the ignition switch to LOCK (0).

- 2. Jump the SCS line with the HDS.

- 3. Disconnect the following connector.

PCM connector A (49P)

- 4. Turn the ignition switch to ON (II).

- 5. Connect terminals 1 and 2 with a jumper wire.

Terminal 1	PCM connector A (49P) No. 12 (RED)
Terminal 2	Body ground

Courtesy of HONDA, U.S.A., INC.

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

YES

The A/C_MG_CLUTCH_RLY_CL- line is OK. Update the PCM - Refer to: PCM Update, or PCM Removal and Installation (Without Keyless Access System), or PCM Removal and Installation (With Keyless Access System) if it does not have the latest software, or substitute a known-good PCM - Refer to: PCM Update, or PCM Removal and Installation (Without Keyless Access System), or PCM Removal and Installation (With Keyless Access System) , then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Update, or PCM Removal and Installation (Without Keyless Access System), or PCM Removal and Installation (With Keyless Access System) .

Check for poor connections or loose terminals at the A/C compressor clutch relay and the PCM. If the connections and terminals are OK, check the A/C compressor clutch relay. If needed, repair open in the A/C_MG_CLUTCH_RLY_CL- wire between the PCM (A12) and the A/C compressor clutch relay, or other parts in the A/C systems.