Key Switch (BCM Input) Check

CHECK KEY SWITCH POWER SUPPLY CIRCUIT

VOLTAGE SPECIFICATION

Terminals			Voltage (V) (Approx.)
(+)		(-)
Key switch and ignition knob switch connector	Terminal	(-)
M73	2	Ground	Battery voltage

Fig 1: Checking Voltage Between Key Switch And Ignition Knob Switch And Ground

Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 2

NG: Check harness between key switch and ignition knob switch and fuse.

CHECK KEY SWITCH OPERATION

Check continuity of key switch and ignition knob switch.

CONTINUITY SPECIFICATION

Terminal		Condition of key switch	Continuity
Key switch and ignition knob switch		Condition of key switch	Continuity
1	2	Insert mechanical key into ignition switch	Yes
1	2	Remove mechanical key from ignition switch	No

Fig 2: Checking Continuity Of Key Switch And Ignition Knob Switch

Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 3

NG: Replace key cylinder assembly (built-in key switch).

CHECK KEY SWITCH CIRCUIT

Check continuity between BCM connector (A) M18 terminal 37 and key switch and ignition knob switch connector (B) terminal 1.

CONTINUITY SPECIFICATION

A		B		Continuity
BCM connector	Terminal	Key switch and ignition knob switch connector	Terminal	Continuity
M18	37	M73	1	Yes

Fig 3: Checking Continuity Between BCM Connector (A) M18 Terminal 37 And Ground

Courtesy of NISSAN MOTOR CO., U.S.A.

Check continuity between BCM connector (A) M18 terminal 37 and ground.

CONTINUITY SPECIFICATION

OK or NG

OK: Key switch (BCM input) circuit is OK.

NG: Repair or replace harness between key switch and ignition knob switch and BCM.