4WD Control Symptom Diagnosis

Diagnose 4WD system after performing the following inspections:

SYMPTOM CHART

Condition	Possible Cause	Action
4WD system does not operate	2WD/i-AWD switch faulty	Check switch. Refer to 2WD/I-AWD SWITCH INSPECTION .
	Coupling air temperature sensor faulty	Check coupling air temperature sensor. Refer to COUPLING AIR TEMPERATURE SENSOR INSPECTION .
	Coupling assembly faulty	Check coupling assembly. Refer to COUPLING ASSEMBLY INSPECTION .
	Transfer oil temperature sensor faulty	Check transfer oil temperature sensor. Refer to TRANSFER OIL TEMPERATURE SENSOR INSPECTION .
	Wiring or grounding faulty	Repair wiring .
	4WD control module faulty	Check 4WD control module. Refer to INSPECTION OF 4WD CONTROL MODULE AND ITS CIRCUITS .
Noise	Damaged or worn bearing(s)	Refer to REAR DIFFERENTIAL INSPECTION .