HVAC System (Auto A/C) (Diagnostics)

Diagnostics with Phenomenon

INSPECTION

1. Perform the diagnosis according to the diagnostic procedure of the corresponding symptom that is shown in the symptom list.
2. If there are multiple symptoms, perform the diagnosis in the symptom sequence (1 -> 2 -> ... -> 13).

1. SYMPTOM LIST






DIAGNOSTIC PROCEDURE WITH PHENOMENON

1. NOTHING IS DISPLAYED ON THE SCREEN. NO ILLUMINATION APPEARS ON THE INDICATOR.

TROUBLE SYMPTOM:
- Nothing is displayed on the screen or no illumination appears on the indicator when pressing the AUTO button while the ignition switch is in ON.
- A/C control panel self-diagnosis fails to operate.

TROUBLE CAUSE:
- A/C control panel power supply circuit failure
- CAN communication failure

WIRING DIAGRAM:













2. AIR CONDITIONER DOES NOT STOP WHEN PRESSING THE OFF SWITCH.

TROUBLE SYMPTOM:
Blower fan does not switch to OFF, inlet opening does not switch to FRESH, and compressor does not switch to OFF, when pressing the OFF switch.

TROUBLE CAUSE:
- CAN communication failure
- A/C control panel failure
- Blower motor failure
- Intake actuator failure
- Compressor failure






3. WINDSHIELD GRASS DOES NOT CLEAR WHEN PRESSING THE DEF SWITCH.

TROUBLE SYMPTOM:
Defroster indicator does not illuminate, outlet opening does not switch to DEF, compressor does not switch to ON, and inlet opening does not switch to FRESH, when pressing the DEF switch.

TROUBLE CAUSE:
- CAN communication failure
- A/C control panel failure
- Mode door actuator failure
- Compressor failure
- Intake actuator failure






4. COLD AIR NOT EMITTED

TROUBLE SYMPTOM:
Cold air not emitted.

TROUBLE CAUSE:
- Airflow failure
- Refrigerant pressure failure
- CAN communication failure
- A/C control panel failure
- Air mix actuator RH failure
- Air mix actuator LH failure (only with left/right independent air conditioning function)
- Intake actuator failure
- Evaporator sensor failure
- RECIRC sensor failure
- FRESH sensor failure
- Sunload sensor failure









5. WARM AIR NOT EMITTED

TROUBLE SYMPTOM:
Warm air not emitted.

TROUBLE CAUSE:
- Airflow failure
- Coolant level failure
- CAN communication failure
- A/C control panel failure
- Air mix actuator RH failure
- Air mix actuator LH failure (only with left/right independent air conditioning function)
- Intake actuator failure
- Evaporator sensor failure
- RECIRC sensor failure
- FRESH sensor failure
- Sunload sensor failure









6. COMPARTMENT TEMPERATURE IS LOWER THAN SETTING TEMPERATURE

TROUBLE SYMPTOM:
Compartment temperature is lower than setting temperature.

TROUBLE CAUSE:
- Airflow is large.
- Refrigerant pressure failure
- CAN communication failure
- A/C control panel failure
- Air mix actuator RH failure
- Air mix actuator LH failure (only with left/right independent air conditioning function)
- Evaporator sensor failure
- RECIRC sensor failure
- FRESH sensor failure
- Sunload sensor failure









7. COMPARTMENT TEMPERATURE IS HIGHER THAN SETTING TEMPERATURE

TROUBLE SYMPTOM:
Compartment temperature is higher than setting temperature.

TROUBLE CAUSE:
- Airflow is large.
- CAN communication failure
- A/C control panel failure
- Air mix actuator RH failure
- Air mix actuator LH failure (only with left/right independent air conditioning function)
- Intake actuator failure
- Evaporator sensor failure
- RECIRC sensor failure
- FRESH sensor failure
- Sunload sensor failure









8. AIR DOES NOT COME OUT. AIRFLOW IS LOW.

TROUBLE SYMPTOM:
- Airflow is low.
- Air does not come out when operating the fan dial.

TROUBLE CAUSE:
- Airflow failure
- CAN communication failure
- A/C control panel failure
- Blower motor failure

WIRING DIAGRAM:
















9. AIR CANNOT BE CONTROLLED.

TROUBLE SYMPTOM:
- The blower rotates even though the blower switch is not turned on.
- The blower motor continues to rotate at high speed. (Not adjustable.)

TROUBLE CAUSE:
- Airflow failure
- CAN communication failure
- A/C control panel failure
- Blower motor failure

WIRING DIAGRAM:













10. COOL AIR DOES NOT COME OUT WHEN PRESSING THE A/C SWITCH. FOG CANNOT BE CLEARED. (COMPRESSOR DOES NOT OPERATE.)

TROUBLE SYMPTOM:
Compressor does not operate after turning the A/C switch to ON and fan dial between LO and HI.

TROUBLE CAUSE:
Compressor failure

WIRING DIAGRAM:
















11. UNABLE TO SWITCH SUCTION VENTS

TROUBLE SYMPTOM:
Inlet opening does not switch RECIRC -> FRESH or FRESH -> RECIRC each time pressing the FRESH/RE-CIRC switch.

TROUBLE CAUSE:
Intake actuator failure.






12. UNABLE TO SWITCH VENTS

TROUBLE SYMPTOM:
- Unable to switch blow vents.
- Outlet opening does not switch in the sequence of FACE -> B/L -> FOOT -> F/D after operating the mode switch or mode dial.

TROUBLE CAUSE:
Mode actuator failure.






13. ILLUMINATION DOES NOT ILLUMINATE OR CANNOT BE DIMMED.

TROUBLE SYMPTOM:
Illumination does not illuminate after operating the lighting switch. Illumination does not dim after operating the illumination control.

TROUBLE SYMPTOM:
Illumination circuit is open.

WIRING DIAGRAM: