A/C Signal Circuit Troubleshooting Idle Control System

Engine

A/C Signal Circuit Troubleshooting - Idle Control System

A/C Signal Circuit Troubleshooting

1. A/C compressor clutch condition check:

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 A/C System Test.

2. A/C system check:

A/C system check
-1. Check the A/C system.

Does the A/C system operate?
-YES- The air conditioning system circuit is OK.
-NO- Go to step 3.

3. A/C compressor clutch circuit check:

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- The A/C compressor clutch circuit is OK. Do the A/C system test A/C System Test.
-NO- Go to step 4.

4. Open wire check (A/C_MG_CLUTCH_RLY_CL- line):

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.





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

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









Is there a clicking noise from the A/C compressor clutch?
-YES- The A/C_MG_CLUTCH_RLY_CL- wire is OK. Update the ECM ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM Service and Repair, then recheck. If the symptom/indication goes away and the ECM was updated, troubleshooting is complete. If the symptom/indication goes away and the ECM was substituted, replace the original ECM Service and Repair.
-NO- Check for poor connections or loose terminals at the A/C compressor clutch relay and the ECM. 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 ECM (A12) and the A/C compressor clutch relay, or other parts in the A/C systems.