Inspection Procedure 1: Cool air does not come

CIRCUIT OPERATION

While the engine is running, with the blower switch ON, and when the temperature control dial is set to MAX COOL, if cool air does not come out from the vents, A/C compressor control circuit system may be defective.

PROBABLE CAUSES

Malfunction of the A/C evaporator air outlet thermistor
Malfunction of the dual pressure switch
Malfunction of the engine-ECU
Damaged the wiring harness or connectors
Improper amount of refrigerant

DIAGNOSIS PROCEDURE

STEP 1. Connector check: A-33 A/C compressor and clutch assembly connector and C-105 engine-ECU

Q. Is the check result normal?

Go to Step 2.

Repair the connector.

STEP 2. Voltage measurement at A-33 A/C compressor and clutch 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 19.

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

Q. Is the check result normal?

Go to Step 3.

Refer to Inspection Procedure 4 " The A/C compressor and clutch assembly does not work

STEP 3. Check that the blower motor operates when the blower switch is moved to the "4 (HI)" position.

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

(2)Turn the blower switch to the "4 (HI) " position.

Q. Does the blower motor operate when the blower switch is moved to the "4 (HI)" position?

	Go to Step 4.

	Refer to Inspection procedure 2 "The blower does not work ."

STEP 4. Resistance measurement at the C-05 A/C switch module connector.

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

(2)Measure the resistance between terminal 5 and body earth.
OK: Continuity (Less than 2Ω)

Q. Is the check result normal?

Go to Step 6.

Go to Step 5.

STEP 5. Check the wiring harness between C-05 A/C switch module connector terminal No.5 and body earth.

Check the A/C switch module earth 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 6. Voltage measurement at C-05 A/C switch module 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 10 and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 8.

Go to Step 7.

STEP 7. Check the wiring harness between C-05 A/C switch module connector terminal No.10 and the ignition switch (IG2).

note

Prior to the wiring harness inspection, check junction block connector C-209 and C-207, and repair if necessary.

Check the blower 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 8. Connector check: C-06 blower switch connector

Q. Is the check result normal?

Go to Step 9.

Repair the connector.

STEP 9. Check the wiring harness between C-06 blower switch connector terminal No.2 and C-05 A/C switch module connector terminal No.4.

note

Prior to the wiring harness inspection, check joint connector C-10 and repair if necessary.

Check the engine-ECU signal line for open and short circuit.

Check the blower switch signal line and earth line for open and short circuit.

Q. Is the check result normal?

Go to Step 10 <Vehicles for EURO6>.

Go to Step 12 <Except for EURO6>.

Repair the wiring harness.

STEP 10. Connector check: C-103 engine-ECU connector

Q. Is the check result normal?

Go to Step 11.

Repair the connector.

STEP 11. Check the wiring harness between C-103 engine-ECU connector terminal No.125 and C-05 A/C switch module connector terminal No.4.

note

Prior to the wiring harness inspection, check intermediate connector C-52 <LHD> or C-34 <RHD>, and repair if necessary.

Check the engine-ECU signal line for open and short circuit.

Q. Is the check result normal?

Go to Step 12 .

Repair the wiring harness.

STEP 12. Connector check: C-21 A/C evaporator air outlet thermistor connector

Q. Is the check result normal?

Go to Step 13.

Repair the connector.

STEP 13. Resistance measurement at the C-21 A/C evaporator air outlet thermistor connector.

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

(2)Measure the resistance between terminal 1 and body earth.
OK: Continuity (Less than 2Ω)

Q. Is the check result normal?

Go to Step 15.

Go to Step 14.

STEP 14. Check the wiring harness between C-05 A/C switch module connector terminal No.5 and body earth.

Check the A/C switch module earth 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 wiring harness between C-05 A/C switch module connector terminal No.3 and C-21 A/C evaporator air outlet thermistor connector terminal No.2.

Check the input line for open and short circuit.

Q. Is the check result normal?

Go to Step 16.

Repair the wiring harness.

STEP 16. Connector check: A-38 dual pressure switch connector

Q. Is the check result normal?

Go to Step 17.

Repair the connector.

STEP 17. Check the dual pressure switch.

Refer to

Q. Is the check result normal?

	Go to Step 18.

	Replace the A/C receiver assembly.

STEP 18. Check the wiring harness between C-21 A/C evaporator air outlet thermistor connector terminal No.4 and A-38 dual pressure switch connector terminal No.2.

note

Prior to the wiring harness inspection, check intermediate connector C-54 <LHD> or C-14 <RHD>, and repair if necessary.

Check the dual pressure switch signal line.

Q. Is the check result normal?

Go to Step 19.

Repair the wiring harness.

STEP 19. Check the wiring harness between A-38 dual pressure switch connector terminal No.1 and C-105 engine-ECU connector terminal No.15.

note

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

Check the dual pressure switch signal line.

Q. Is the check result normal?

Go to Step 20.

Repair the wiring harness.

STEP 20. Check the A/C compressor clutch operation.

Refer to

Q. Can the sound of the A/C compressor clutch (click) be heard?

	Go to Step 21.

	Replace the A/C compressor clutch.

STEP 21. Refrigerant level check

Check that the refrigerant level is adequate. Refer to

Q. Is the check result normal?

	Go to Step 22.

	Charge or remove the refrigerant level. Refer to .

STEP 22. Replace the A/C switch module, and then recheck the trouble symptom

Check that the cooler works normally.

Q. Is the check result normal?

	This diagnosis is complete.

	Go to Step 23.

STEP 23. Replace the A/C evaporator air outlet thermistor, and then recheck the trouble symptom

Check that the cooler works normally.

Q. Is the check result normal?

	This diagnosis is complete.

	Replace the engine-ECU.