Inspection Procedure 1: Cool air does not come


COMMENTS ON TROUBLE SYMPTOM
The blower system, the compressor system or the communication system between the engine-ECU and the A/C-ECU may be defective if there is no cool air coming from the spit hole.

PROBABLE CAUSES

  • Malfunction of air thermo sensor
  • Malfunction of dual pressure switch
  • Damaged harness wires and connectors
  • Malfunction of engine-ECU
  • Malfunction of the automatic A/C control panel (A/C-ECU)

DIAGNOSIS PROCEDURE

STEP 1. Check the operation of the heater control panel
Check that the air selection switch, rear window defogger switch and air volume control dial can operate.

Q. Is the check result normal?
Go to Step 2.
Inspection Procedure 9: Refer to A/C-ECU power supply system .

STEP 2. Connector check: A-33 A/C compressor assembly connector and C-105 engine-ECU connector



Q. Is the check result normal?

Go to Step 3.

Repair the connector.

STEP 3. Voltage measurement at A-33 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 C-105 and earth terminal 40.

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

Q. Is the check result normal?

Go to Step 4.

Refer to Inspection Procedure 5 " The compressor does not work ".

STEP 4. Check the blower motor operation
Check that the blower motor operates under the following conditions.

  • ignition switch: ON
  • Blower speed selection dial: MAX

Q. Is the check result normal?
Go to Step 5.
Refer to Inspection Procedure 2 " The blower does not work ".

STEP 5. Connector check: A-38 dual pressure switch connector

Q. Is the check result normal?

Go to Step 6.

Repair the connector.

STEP 6. Check the dual pressure switch.
Refer to .

Q. Is the check result normal?
Go to Step 7.
Replace the dual pressure switch.

STEP 7. Connector check: C-46 power transistor connector and C-44 A/C-ECU connector


Q. Is the check result normal?

Go to Step 8.

Repair the connector.

STEP 8. Check the wiring harness between C-46 power transistor connector (terminals 1 and 3) and C-44 A/C-ECU connector (terminals 36 and 35).



  • Check the input line for open circuit.

Q. Is the check result normal?

Go to Step 9.

Repair the wiring harness.

STEP 9. Connector check: C-43 A/C-ECU connector


Q. Is the check result normal?

Go to Step 10.

Repair the connector.

STEP 10. Check the wiring harness between C-43 A/C-ECU connector terminal No.5 and A-38 dual pressure switch connector terminal No.2.




note Prior to the wiring harness inspection, check intermediate connector C-54, and repair if necessary.

  • Check the input line for open circuit.

Q. Is the check result normal?

Go to Step 11.

Repair the wiring harness.

STEP 11. Check the wiring harness between C-105 engine-ECU connector terminal No.15 and A-38 dual pressure switch connector terminal No.2.




note Prior to the wiring harness inspection, check intermediate connector A-28, and repair if necessary.

  • Check the input 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 C-105 engine-ECU connector terminal No.13 and C-43 A/C-ECU connector terminal No.16.





note Prior to the wiring harness inspection, check intermediate connector C-53, and repair if necessary.

  • Check the input line for open circuit.

Q. Is the check result normal?

Go to Step 13.

Repair the wiring harness.

STEP 13. Check the refrigerant level.
Refer to .

Q. Is the refrigerant level correct?
Go to Step 14.
Correct the refrigerant level (Refer to On-vehicle Service .)

STEP 14. 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.