Inspection Procedure 1: Communication with the M.U.T.-III is not possible.

COMMENTS ON TROUBLE SYMPTOM

If communication with all other systems is not possible, there is a high possibility that there is a malfunction of the diagnosis line. If only the A/C system can not communicate with the M.U.T.-III, the A/C-ECU may be defective.

PROBABLE CAUSES

Malfunction of the A/C-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check that Engine-ECU <M/T> or Engine-A/T-ECU <A/T> communicates with the M.U.T.-III

Use the M.U.T.-III to confirm that it communicates with the engine-ECU <M/T> or engine-A/T-ECU <A/T>.

Q. Is the check result normal?

	Go to Step 2.

	Diagnose the MPI system. Refer to GROUP 13A - Troubleshooting <6G7>, or GROUP 13B - Troubleshooting <4M4>.

STEP 2. Connector check: D-127 diagnosis connector

Q. Is the check result normal?

	Go to Step 3.

	Repair the connector.

STEP 3. Voltage measurement at D-127 diagnosis connector.

(1)Disconnect the connector, and measure at the wiring harness side.

(2)Turn the ignition switch to the ON position.

(3)Measure the voltage between terminal 16 and body earth.
OK: System voltage

Q. Is the check result normal?

	Go to Step 5.

	Go to Step 4.

STEP 4. Check the wiring harness between D-127 diagnosis connector terminal No.16 and fusible link (2).

note

Prior to the wiring harness inspection, check intermediated connector D-240, junction block connectors D-404 and D-405, and repair if necessary.

Check the motor power supply line for open circuit.

Q. Is the check result normal?

	The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).

	Repair the wiring harness.

STEP 5. Connector check: D-08 A/C-ECU connector

Q. Is the check result normal?

	Go to Step 6.

	Repair the connector.

STEP 6. Check the wiring harness between D-127 diagnosis connector terminal No.7 and D-08 A/C-ECU connector terminal No.31.

note

Prior to the wiring harness inspection, check joint connector D-34, and repair if necessary.

Check the motor power supply line for open circuit.

Q. Is the check result normal?

	Replace the A/C-ECU.

	Repair the wiring harness.