Diagnosis Procedure

WARNING: This page is about a different car, the 2020 Infiniti QX60. However, it is still accessible from the selected car via links, so may be relevant.

CHECK POWER SOURCE

Turn ignition switch OFF.
Disconnect BCM connector M18.

Check voltage between BCM connector M18 terminal 27 and ground while pressing the brake pedal.

BCM		Ground	Condition	Voltage
Connector	Terminal		Brake pedal depressed	Battery voltage
M18	27

Is the inspection result normal?

YES

GO TO 3.

GO TO 2.

CHECK STOP LAMPS
Do the stop lamps operate normally?

Is the inspection result normal?

YES

Check the following:
- Harness between fuse block (J/B) and BCM.
- Fuse block (J/B).
NO

Refer to appropriate wiring information .

CHECK HARNESS BETWEEN BCM AND CVT SHIFT SELECTOR

Disconnect CVT shift selector connector.

Check continuity between BCM connector M80 terminal 108 and CVT shift selector connector M78 terminal 3.

BCM		CVT shift selector		Continuity
Connector	Terminal	Connector	Terminal	Continuity
M80	108	M78	3	Yes

Check continuity between BCM connector M80 terminal 108 and ground.

BCM		Ground	Continuity
Connector	Terminal
M80	108		No

Is the inspection result normal?

YES

GO TO 4.

Repair or replace harness or connector.

CHECK GROUND CIRCUIT (CVT SHIFT SELECTOR)

Check continuity between CVT shift selector connector M78 terminal 4 and ground.

CVT shift selector		Ground	Continuity
Connector	Terminal
M78	4		Yes

Is the inspection result normal?

YES

Replace CVT shift selector. Refer to Removal and Installation .

Repair or replace harness or connector.