Heater and Ventilation Symptom Diagnosis

Precautions: 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.
	Faulty blower motor relay	Check blower motor relay.
	Faulty blower motor resistor	Check blower motor resistor.
	Faulty blower speed selector	Check blower speed selector.
	Faulty blower motor	Check blower motor.
	Foreign material present	Remove foreign material.
	Faulty wiring or grounding	Repair wiring.
Air outlets do not change or do not agree with air flow selector’s position even if air flow selector is changed	Broken or bent air flow control cable	Check air flow control cable.
	Faulty air flow selector	Check air flow selector.
	Incorrect installation of air flow control cable	Check position of cable and adjust it if necessary.
	Leaked or clogged air ducts	Repair air ducts.
	Broken air flow control door assembly	Repair air flow control door assembly.
Air intake door does not change even if air intake mode is changed	Blown fuse	Check related fuses and check for short circuit to ground.
	Faulty air intake control actuator	Check air intake control actuator.
	Faulty air intake switch	Check air intake switch.
	Broken air intake door	Repair air intake door.
	Faulty wiring or grounding	Repair wiring.
Warm air does not come out or insufficient heating (Faulty temperature control)	Broken or bent temperature control cable	Check temperature control cable.
	Faulty temperature selector	Check temperature selector.
	Incorrect installation of temperature control cable	Check position of cable and adjust it if necessary.
	Clogged air ducts	Repair air ducts.
	Faulty additional heater system (if equipped)	Check additional heater system.
	Faulty thermostat (Petrol model)	Check thermostat.
	Broken temperature control door assembly	Repair temperature control door assembly.
	Leaky or clogged heater core	Replace heater core.
	Leaky or clogged heater hoses	Replace heater hoses.
Heating performance is poor (for additional heater system)	Blown fuse	Check related fuses and check for short circuit to ground.
	Faulty additional heater relays	Check additional heater relays.
	Faulty additional heater	Check additional heater.
	Faulty ECM	Check ECM.
	Faulty max hot switch	Check max hot switch.
	Faulty wiring or grounding	Repair wiring.