Inspection Procedure 8: The compressor does not work <LHD>

COMMENTS ON TROUBLE SYMPTOM
When the A/C compressor does not work, the A/C compressor circuit system or the CAN bus line may be defective.

PROBABLE CAUSES

  • Malfunction of A/C compressor
  • Malfunction of A/C compressor relay
  • Malfunction of A/C pressure sensor
  • Damaged harness wires and connectors
  • Malfunction of engine-ECU <M/T> or engine-A/T-ECU <A/T>
  • Malfunction of the A/C-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
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 lines. (Refer to GROUP 54F, 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 04: Pressure sensor

Q. Is the check result normal?
Go to Step 4.
Inspection Procedure 20: Refer to A/C pressure sensor system .

STEP 4. Connector check: B-120 A/C compressor assembly connector and C-110 engine-ECU connector <M/T> or engine-A/T-ECU <A/T>


Q. Is the check result normal?

Go to Step 5.

Repair the connector.

STEP 5. Voltage measurement at B-120 A/C compressor assembly connector.

(1)Disconnect the connector, and measure at the wiring harness side.
(2)Turn the ignition switch to the "ON" position.


(3)Disconnect engine-ECU connector or engine-A/T-ECU connector C-110 and earth terminal 8. <Except vehicles for GCC>


(4)Disconnect engine-ECU connector or engine-A/T-ECU connector C-110 and earth terminal 16. <Vehicles for GCC>

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

Q. Is the check result normal?

Go to Step 13.

Go to Step 6.

STEP 6. Check the A/C compressor relay continuity.
Refer to .

Q. Is the A/C compressor relay in good condition?
Go to Step 7.
Replace the A/C compressor relay.

STEP 7. Voltage measurement at B-16X A/C compressor relay connector.

(1)Remove the relay, and measure at the relay block side.
(2)Turn the ignition switch to the "ON" position.

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

Q. Is the check result normal?

Go to Step 9.

Go to Step 8.

STEP 8. Check the wiring harness between B-16X A/C compressor relay connector terminal No.3 and the ignition switch (IG2).




note Prior to the wiring harness inspection, check junction block connectors C-202, C-205, joint connector C-31 and intermediate connector C-17, 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 9. Voltage measurement at B-16X A/C compressor relay connector.

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

(2)Voltage between terminal 4 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-16X A/C compressor relay connector terminal No.4 and the fusible link (26).


note Prior to the wiring harness inspection, check intermediate connector A-16, 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. Check the wiring harness between B-16X A/C compressor relay connector terminal No.2 and C-110 engine-ECU <M/T> or engine-A/T-ECU <A/T> connector terminal No.8.



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

Q. Is the check result normal?

Go to Step 12.

Repair the wiring harness.

STEP 12. Check the wiring harness between B-16X A/C compressor relay connector terminal No.1 and B-120 A/C compressor assembly connector terminal No.1.



  • 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 13. Check the magnetic clutch operation.
Refer to .

Q. Can the sound of the magnetic clutch (click) be heard?
Go to Step 14.
Replace the compressor magnet clutch.

STEP 14. Check the refrigerant level.
Refer to .

Q. Is the refrigerant level correct?
Go to Step 15.
Correct the refrigerant level (Refer to or ).

STEP 15. Replace the A/C-ECU, and then recheck the trouble symptom
Check that the compressor works normally.

Q. Is the check result normal?
This diagnosis is complete.
Replace the engine-ECU or the engine-A/T-ECU.