A/C System Symptom Diagnosis
Precautions: Precautions for Diagnosing Trouble · General safety (00)
| Condition | Possible Cause | Action |
|---|---|---|
|
Blower motor does not operate
|
Blown fuse
|
Check related fuses, and then check for short circuit to ground.
|
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Faulty blower motor relay
|
Check blower motor relay.
|
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Faulty blower motor
|
Check blower motor.
|
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Faulty blower motor controller
|
Check blower motor controller.
|
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Faulty auto A/C panel
|
Check auto A/C panel.
|
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Faulty HVAC control module
|
Check HVAC control module.
|
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Faulty wiring or grounding
|
Repair wiring.
|
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No cool air comes out (A/C system does not operate)
|
Blown fuse
|
Check related fuses, and then check for short circuit to ground.
|
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Faulty A/C compressor relay
|
Check A/C compressor relay.
|
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|
Faulty auto A/C panel
|
Check auto A/C panel.
|
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Faulty BCM
|
Check BCM.
|
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Faulty ESP®
|
Check ESP® control module.
|
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Faulty ECM and its circuit
|
Check ECM.
|
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Faulty magnet clutch (petrol model)
|
Check magnet clutch.
|
|
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Faulty compressor pulley (diesel model)
|
Check compressor pulley.
|
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Faulty compressor ON/OFF valve (diesel model)
|
Check compressor ON/OFF valve.
|
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Loose or broken compressor drive belt (petrol model)
|
Check compressor drive belt.
|
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Loose or broken generator drive belt (diesel model)
|
Check generator drive belt.
|
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Faulty compressor
|
Check compressor.
|
|
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Faulty ECT sensor
|
Check ECT sensor.
•M16A model:
•K14C model: •D16AA model: |
|
|
No refrigerant
|
Check amount of refrigerant and system for leakage.
Recover refrigerant, evacuate and charge A/C system.
|
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|
Faulty A/C refrigerant pressure sensor
|
Check A/C refrigerant pressure sensor.
|
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Faulty evaporator temperature sensor
|
Check evaporator temperature sensor.
|
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Faulty HVAC control module
|
Check HVAC control module.
|
|
|
Faulty wiring or grounding
|
Repair wiring.
|
|
|
No cool air comes out (radiator cooling fan motor does not operate)
|
Blown fuse
|
Check related fuses, and then check for short circuit to ground.
|
|
Faulty radiator cooling fan relay
|
Check radiator cooling fan relay.
|
|
|
Faulty radiator cooling fan motor
|
Check radiator cooling fan motor.
•M16A model:
•K14C model: •D16AA model: |
|
|
Faulty ECM
|
Check ECM.
|
|
|
Faulty HVAC control module
|
Check HVAC control module.
|
|
|
Faulty wiring or grounding
|
Repair wiring.
|
|
|
Cool air does not come out or insufficient cooling (compressor in normal operation)
|
Faulty blower motor
|
Check blower motor.
|
|
Faulty temperature control actuator
|
Check temperature control actuator.
|
|
|
Air leakage from HVAC unit or air duct
|
Repair HVAC unit or air duct.
|
|
|
Loose or broken compressor drive belt (petrol model)
|
Check compressor drive belt.
|
|
|
Loose or broken generator drive belt (diesel model)
|
Check generator drive belt.
|
|
|
Faulty magnet clutch (petrol model)
|
Check magnet clutch.
|
|
|
Faulty compressor pulley (diesel model)
|
Check compressor pulley.
|
|
|
Faulty compressor ON/OFF valve (diesel model)
|
Check compressor ON/OFF valve.
|
|
|
Faulty compressor
|
Check compressor.
|
|
|
Faulty expansion valve
|
Check expansion valve.
|
|
|
Clogged desiccant
|
Check desiccant and cap.
|
|
|
Faulty heater and ventilation system
|
Check HVAC unit.
|
|
|
Insufficient or excessive charge of refrigerant
|
Check amount of refrigerant and system for leakage.
|
|
|
Excessive compressor oil in A/C system
|
Drain excessive compressor oil from A/C system circuit and compressor.
|
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|
Clogged condenser
|
Check condenser.
|
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|
Clogged or frosted evaporator
|
Check evaporator and evaporator temperature sensor.
•Evaporator:
•Evaporator temperature sensor: |
|
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Faulty evaporator temperature sensor
|
Check evaporator temperature sensor.
|
|
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Air in A/C system
|
Replace condenser, and then evacuate and charge A/C system with refrigerant.
|
|
|
Cool air does not come out intermittently
|
Faulty magnet clutch (petrol model)
|
Check magnet clutch.
|
|
Faulty compressor pulley (diesel model)
|
Check compressor pulley.
|
|
|
Faulty compressor ON/OFF valve (diesel model)
|
Check compressor ON/OFF valve.
|
|
|
Excessive amount of refrigerant
|
Check the amount of refrigerant.
|
|
|
Faulty expansion valve
|
Check expansion valve.
|
|
|
Faulty evaporator temperature sensor
|
Check evaporator temperature sensor.
|
|
|
Excessive moisture in A/C system
|
Replace condenser, and then evacuate and charge A/C system.
|
|
|
Faulty wiring connection
|
Repair wiring if necessary.
|
|
|
Cool air comes out only at high speed
|
Loose or broken compressor drive belt (petrol model)
|
Check compressor drive belt.
|
|
Loose or broken generator drive belt (diesel model)
|
Check generator drive belt.
|
|
|
Faulty compressor
|
Check compressor.
|
|
|
Clogged condenser
|
Check condenser.
|
|
|
Insufficient charge of refrigerant
|
Check the amount of refrigerant and system for leakage.
|
|
|
Air in A/C system
|
Replace condenser, and then evacuate and charge A/C system with refrigerant.
|
|
|
Cool air does not come out only at high speed
|
Excessive amount of refrigerant
|
Check the amount of refrigerant.
|
|
Frosted evaporator
|
Check evaporator and evaporator temperature sensor.
•Evaporator:
•Evaporator temperature sensor: |
|
|
Insufficient cool air flow
|
Faulty blower motor
|
Check blower motor.
|
|
Air leakage from HVAC unit or air duct
|
Repair HVAC unit or air duct.
|
|
|
Clogged or frosted evaporator
|
Check evaporator and evaporator temperature sensor.
•Evaporator:
•Evaporator temperature sensor: |
|
|
Faulty wiring or grounding
|
Repair wiring if necessary.
|