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 DIFFERENTIAL LOCK MODE SWITCH
Check differential lock mode switch. Refer to Component Inspection .

Is the inspection result normal?

YES

GO TO STEP 2 .

NO

Replace differential lock mode switch.

CHECK IGNITION VOLTAGE FOR DIFFERENTIAL LOCK MODE SWITCH

Turn the ignition switch OFF.
Disconnect differential lock mode switch harness connector.

Check the voltage between differential lock mode switch harness connector and ground.

Differential lock mode switch

Voltage

(Approx.)

Connector

Terminal

M72

Ground

0 V

Turn the ignition switch ON.
CAUTION: Never start the engine.

Check the voltage between differential lock mode switch harness connector and ground.

Differential lock mode switch

Voltage

(Approx.)

Connector

Terminal

M72

Ground

Battery voltage

Is the inspection result normal?

YES

GO TO STEP 4 .

GO TO STEP 3 .

CHECK IGNITION SIGNAL CIRCUIT FOR DIFFERENTIAL LOCK MODE SWITCH

Turn the ignition switch OFF.
Check fuse [No. 30 located in the fuse block (J/B)].
Disconnect fuse block (J/B) harness connector.

Check the continuity between differential lock mode switch harness connector and fuse block (J/B) harness connector.

Differential lock mode switch		Fuse block (J/B)		Continuity
Connector	Terminal	Connector	Terminal	Continuity
M72	4	M4	7P	Yes

Check the continuity between differential lock mode switch harness connector and the ground.

Differential lock mode switch		-	Continuity
Connector	Terminal
M72	4	Ground	No

Is the inspection result normal?

YES

Perform the trouble diagnosis for ignition power supply circuit. Refer to SYSTEM WIRING DIAGRAMS .

Repair or replace the malfunctioning parts.

CHECK DIFFERENTIAL LOCK MODE SWITCH SIGNAL

Turn the ignition switch OFF.
Connect differential lock mode switch harness connector.
Disconnect differential lock control unit harness connector.
Turn the ignition switch ON.
CAUTION: Never start the engine.

Check the voltage between differential lock control unit harness connector and ground.

Differential lock control unit		-	Condition	Voltage (Approx.)
Connector	Terminal
B77	5	Ground	Differential lock mode switch: ON	Battery voltage
			Differential lock mode switch: OFF	0 V
	14		Differential lock mode switch: ON	0 V
			Differential lock mode switch: OFF	Battery voltage

Is the inspection result normal?

YES

GO TO STEP 5 .

GO TO STEP 6 .

CHECK DIFFERENTIAL LOCK MODE SWITCH SIGNAL CIRCUIT

Turn the ignition switch OFF.
Disconnect differential lock mode switch harness connector.

Check the continuity between differential lock control unit harness connector and differential lock mode switch harness connector.

Differential lock control unit		Differential lock mode switch		Continuity
Connector	Terminal	Connector	Terminal
B77	5	M72	7	Yes
			8	No
	14		7	No
			8	Yes

Check the continuity between differential lock control unit harness connector and ground.

Differential lock control unit		-	Continuity
Connector	Terminal
B77	5	Ground	No
	14

Is the inspection result normal?

YES

GO TO STEP 6 .

Repair or replace the malfunctioning parts.

CHECK TERMINALS AND HARNESS CONNECTORS
- Check differential lock control unit pin terminals for damage or loose connection with harness connector.
- Check differential lock mode switch pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?

YES

Replace differential lock control unit. Refer to Removal and Installation .

NO

Repair or replace the malfunctioning parts.