Diagnosis Procedure

WARNING: This page is about a different car, the 2018 Nissan Titan XD and 2018 Nissan Titan. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FUSE
1. Turn ignition switch OFF.
2. Check 15A fuses [No. 17 and 27, located in fuse block (J/B)].
  NOTE: Refer to the appropriate system Terminal Arrangement .
Is the inspection result normal?

YES

GO TO 2 .

NO

Replace the blown fuse after repairing the affected circuit.

CHECK FRONT BLOWER MOTOR POWER SUPPLY

Disconnect front blower motor connector.
Turn ignition switch ON.

Check voltage between front blower motor harness connector and ground.

(+)		(-)	Voltage (Approx.)
Front blower motor
Connector	Terminal
M44	1	Ground	Battery voltage

Is the inspection result normal?

YES

GO TO 4 .

GO TO 3 .

CHECK FRONT BLOWER RELAY
1. Turn ignition switch OFF.
2. Check front blower relay. Refer to Component Inspection (Front Blower Relay) .
Is the inspection result normal?

YES

Repair harness or connector between front blower motor and fuse.

NO

Replace front blower relay.

CHECK FRONT BLOWER MOTOR CONTROL CIRCUIT

Turn ignition switch OFF.
Connect front blower motor connector.
Disconnect variable blower control connector.
Turn ignition switch ON.

Check voltage between variable blower control harness connector and ground.

(+)		(-)	Voltage (Approx.)
Variable blower control
Connector	Terminal
M130	3	Ground	Battery voltage

Is the inspection result normal?

YES

GO TO 6 .

GO TO 5 .

CHECK FRONT BLOWER MOTOR CONTROL CIRCUIT FOR OPEN

Turn ignition switch OFF.
Disconnect front blower motor connector.

Check continuity between variable blower control harness connector and front blower motor harness connector.

Variable blower control		Front blower motor		Continuity
Connector	Terminal	Connector	Terminal	Continuity
M130	3	M44	2	Yes

Is the inspection result normal?

YES

Replace front blower motor. Refer to Removal and Installation .

Repair harness or connector.

CHECK VARIABLE BLOWER CONTROL GROUND CIRCUIT FOR OPEN

Turn ignition switch OFF.

Check continuity between variable blower control harness connector and ground.

Variable blower control		(-)	Continuity
Connector	Terminal
M130	1	Ground	Yes

Is the inspection result normal?

YES

GO TO 7 .

Repair harness or connector.

CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT

Turn blower control dial fully counterclockwise to the OFF position.

While turning the blower control dial clockwise, through each detent, check voltage between variable blower control and ground.

Variable blower control		(-)	Condition
Connector	Terminal	(-)	Blower control dial detents	Voltage
M130	2	Ground	OFF	0.00
			1	4.00
			2	4.75
			3	5.00
			4	5.50
			5	5.75
			6	6.00
			7	6.50
			8	6.75
			9	7.00
			10	7.50
			11	8.00
			12	8.25
			13	8.50
			14	9.00
			15	9.25
			16	9.75
			17	10.00
			18	10.50
			19	10.75
			20	11.00
			21	11.50
			22	11.75
			23	12.25
			24	12.50

Is the inspection result normal?

YES

Replace variable blower control. Refer to Removal and Installation .

GO TO 8 .

CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT FOR OPEN

Turn ignition switch OFF.
Disconnect variable blower control connector and front air control connector.

Check continuity between variable blower control harness connector and front air control harness connector.

Variable blower control		Front air control		Continuity
Connector	Terminal	Connector	Terminal	Continuity
M130	2	M132	10	Yes

Is the inspection result normal?

YES

GO TO 9 .

Repair harness or connector.

CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT FOR SHORT

Check continuity between variable blower control harness connector and ground.

Variable blower control		(-)	Continuity
Connector	Terminal
M130	2	Ground	No

Is the inspection result normal?

YES

Replace front air control. Refer to Removal and Installation .

Repair harness or connector.