Inspection Procedure 6: The air conditioner does not work at all.

COMMENTS ON TROUBLE SYMPTOM

If the A/C compressor does not operate, the A/C compressor circuit system or the CAN bus lines may be defective.

PROBABLE CAUSE

Malfunction of the Engine-ECU <M/T> or Engine-A-M/T-ECU <Automated manual transmission>
Malfunction of the A/C compressor
Malfunction of the engine control relay

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics

warning

Since the radiator fan rotates during CAN bus line diagnostics, make sure that no one is servicing the engine compartment before diagnosing the CAN bus line. Since the CAN communication stops when diagnosing the CAN bus line, the ETACS-ECU detects the time-out of the engine-ECU, and activates the radiator fan to prevent overheating as fail-safe.

Use the M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?

	Go to Step 2.

	Repair the CAN bus line (Refer to GROUP 54C, Troubleshooting ).

STEP 2. M.U.T.-III diagnosis code

Check whether the air conditioner sets a diagnosis code or not.

Q. Is the check result normal?

	Go to Step 3.

	Refer to diagnosis code chart .

STEP 3. M.U.T.-III data list

Check that the following service data display contents are normal. (Refer to

Item 11: A/C Pressure sensor

Q. Is the check result normal?

	Go to Step 4.

	Inspection Procedure 9: Refer to A/C pressure sensor system .

STEP 4. Check the blower system.

(1)Turn the ignition switch to the "ON" position.

(2)Set the blower switch to the position other than OFF.

Q. Does the blower motor work normally?

	Go to Step 5.

	Refer to Inspection procedure 2 "Blower fan and motor do not turn ."

STEP 5. Connector check: A-124 A/C compressor connector and A-09 Engine-ECU <M/T> or Engine-A-M/T-ECU <Automated manual transmission>

Q. Is the check result normal?

Go to Step 6.

Repair the connector.

STEP 6. Voltage measurement at A-124 A/C compressor connector.

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

(2)Disconnect A-09 Engine-ECU <M/T> or Engine-A-M/T-ECU <Automated manual transmission> and earth terminal 95.

(3)Voltage between terminal 1 and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 15.

Go to Step 7.

STEP 7. Connector check: B-207 A/C compressor relay connector

Q. Is the check result normal?

Go to Step 8.

Repair the connector.

STEP 8. Check the engine control relay continuity.

Refer to GROUP 13A, On-vehicles Service - Engine Control Relay Continuity Check

. <134>

Refer to GROUP 13B, On-vehicles Service - Engine Control Relay Continuity Check

. <135>

Q. Is the engine control relay in good condition?

	Go to Step 9.

	Replace the engine control relay.

STEP 9. Measure the voltage measurement at B-207 A/C compressor relay connector.

(1)Remove the relay, and measure at the relay block side.

(2)Voltage between terminal 3 and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 11.

Go to Step 10.

STEP 10. Check the wiring harness between B-207 A/C compressor relay connector terminal No.3 and the fusible link (1).

note

Prior to the wiring harness inspection, check junction block connectors B-208, B-231, B-212 and intermediate connector B-118, and repair if necessary.

Check the A/C compressor relay 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 11. Voltage measurement at B-207 A/C compressor relay connector.

(1)Remove the relay, and measure at the relay block side.

(2)Measure the voltage between terminal 1 and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 13.

Go to Step 12.

STEP 12. Check the wiring harness between B-207 A/C compressor relay connector terminal No.1 and the ignition switch (IG2).

note

Prior to the wiring harness inspection, check junction block connectors B-231, B-230, and repair if necessary.

Check the A/C compressor relay 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 13. Check the wiring harness between B-207 A/C compressor relay connector terminal No.2 and A-09 Engine-ECU <M/T> or Engine-A-M/T-ECU <Automated manual transmission> connector terminal No.95.

note

Prior to the wiring harness inspection, check junction block connectors B-231, intermediate connector B-118, and repair if necessary.

Check the A/C compressor relay power supply line for open circuit.

Q. Is the check result normal?

Go to Step 14.

Repair the wiring harness.

STEP 14. Check the wiring harness between B-207 A/C compressor relay connector terminal No.4 and A-124 A/C compressor connector terminal No.1.

note

Prior to the wiring harness inspection, check junction block connectors B-231, intermediate connector A-13 and B-118, and repair if necessary.

Check the A/C compressor 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 15. Check the A/C compressor.

Refer to

Q. Is the check result normal?

	Go to Step 16.

	Replace the A/C compressor.

STEP 16. Check the refrigerant level.

Refer to

Q. Is the refrigerant level correct?

	Go to Step 17.

	Correct the refrigerant level (Refer to ).

STEP 17. Replace the A/C-ECU, and then recheck the trouble symptom

Check that the A/C works normally.

Q. Is the check result normal?

	This diagnosis is complete.

	Replace the engine-ECU <M/T> or the engine-A-M/T-ECU <Automated manual transmission>.