Key Switch (BCM Input) Check

WARNING: This page is about a different car, the 2007 Nissan Versa. However, it is still accessible from the selected car via links, so may be relevant.

CHECK KEY SWITCH POWER SUPPLY CIRCUIT

Remove mechanical key from ignition switch.
Disconnect key switch and ignition knob switch connector.

Check voltage between key switch and ignition knob switch and ground.

CONNECTOR TERMINAL VOLTAGE SPECIFICATIONS

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

Fig 1: Checking Key Switch Power Supply Circuit

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.

CONNECTOR TERMINAL CONTINUITY SPECIFICATIONS

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

OK or NG

OK >> GO TO 3.

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

Fig 2: Checking Key Switch

CHECK KEY SWITCH CIRCUIT

Disconnect BCM connector.

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

CONNECTOR TERMINAL CONTINUITY SPECIFICATIONS

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

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

CONNECTOR TERMINAL CONTINUITY SPECIFICATIONS

A		Ground	Continuity
BCM connector	Terminal
M18	37		No

Fig 3: Checking Key Switch Circuit

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.