Troubleshooting

Troubleshooting

Symptom Table

Before replacing or repairing air conditioning components, first determine whether the malfunction is related to the refrigerant charge, airflow, or compressor. Use the table below to find the cause of the problem. The numbers indicate the priority of the probable cause. Check each part in order. If necessary, replace these parts. After repair, check the entire system to make sure it operates satisfactorily.

Symptom	Suspect area
No Fan Operation	1. Blower Fuse
	2. Blower Relay
	3. Blower Motor
	4. Blower resistor, power MOSFET or PWM blower module
	5. Blower speed switch or control knob.
	6. Wiring Harness
No Air Temperature Control	1. Engine Coolant Reservoir
	2. Heater Control Unit
	3. Temperature control actuator or cable
Compressor Does Not Operate	1. Cooling Capacity
	2. Air Conditioner Fuse
	3. Compressor
	4. A/C Pressure Sensor
	5. A/C Switch
	6. Evaporator Temperature Sensor
	7. Wiring Harness
	8. High CAN
Does not cool well	1. Cooling Capacity
	2. Refrigerant Pressure
	3. Drive Belt
	4. Compressor
	5. A/C Pressure Sensor
	6. Evaporator Temperature Sensor
	7. A/C Switch
	8. Heater Control Unit
	9. Wiring Harness
	10. High CAN
	11. Temperature control actuator or cable
Insufficient Cooling	1. Cooling Capacity
	2. Drive Belt
	3. Compressor
	4. Condenser
	5. Expansion Valve
	6. Evaporator
	7. Refrigerant Lines
	8. A/C Pressure Sensor
	9. Heater Control Unit
	10. High CAN
Engine Does Not Idle Well with A/C On	1. Engine ECM
	2. Wiring Harness
No Air Flow Control	1. Heater Control Unit
	2. Intake Actuator
No Mode Control	1. Heater Control Unit
	2. Mode Control Actuator or Cable
Cooling Fan Does Not Operate	1. Cooling Fan Fuse
	2. Blower Motor
	3. Blower Resistor, Power MOSFET, or PWM Blower Module
	4. Engine ECM
	5. Wire Harness