Diagnosis Chart By Symptom

WARNING: This page is about a different car, the 2016 Infiniti QX60. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Perform the self - diagnoses with CONSULT before performing the symptom diagnosis. If DTC is detected, perform the corresponding diagnosis.
The following table is based on the condition that front automatic air conditioning system operates normally.

Symptom		Corresponding malfunction part	Reference
Rear air conditioning cannot be controlled by front A/C control. Operation status of rear air conditioning is not indicated on front A/C control display.		A/C auto amp.	Replace A/C auto amp. Refer to REMOVAL AND INSTALLATION .
Rear air conditioning cannot be controlled by rear air control.	Operation status of rear air conditioning is indicated on rear air control display.	Communication signal (rear air control → A/C auto amp.)	Refer to DIAGNOSIS PROCEDURE .
	Operation status of rear air conditioning is not indicated on rear air control display.	Communication signal (A/C auto amp. → rear air control)	Refer to DIAGNOSIS PROCEDURE .
		Rear air control power supply circuit	Refer to DIAGNOSIS PROCEDURE .
Air outlet does not change. Mode door motor (rear) does not operate normally.		Circuit between mode door motor (rear) and A/C auto amp. Mode door motor (rear) control linkage Mode door motor (rear) A/C auto amp.	DIAGNOSIS PROCEDURE
Discharge air temperature does not change. Air mix door motor (rear) does not operate normally.		Circuit between air mix door motor (rear) and A/C auto amp. Air mix door motor (rear) installation condition Air mix door motor (rear) A/C auto amp.	DIAGNOSIS PROCEDURE
Rear blower motor operation is malfunctioning.		Power supply system of rear blower motor Circuit between rear blower motor and A/C auto amp. Rear blower motor A/C auto amp.	DIAGNOSIS PROCEDURE
Insufficient cooling. No cool air comes out. (Air flow volume is normal.)		A/C auto amp. Refrigerant cycle Air leakage from each duct Temperature setting trimmer (rear)	DIAGNOSIS PROCEDURE
Insufficient heating. No warm air comes out. (Air flow volume is normal.)		PTC heater Air leakage from each duct Temperature setting trimmer (rear)	DIAGNOSIS PROCEDURE
Noise is heard when rear blower motor operates.		Mixing any foreign object in rear blower motor Rear blower motor fan breakage Rear blower motor rotation inferiority	COMPONENT INSPECTION (REAR BLOWER MOTOR)