Diagnosis Procedure

WARNING: This page is about a different car, the 2010 Nissan Armada. However, it is still accessible from the selected car via links, so may be relevant.

Regarding Wiring Diagram information, refer to "WIRING DIAGRAM - POWER DOOR LOCK SYSTEM - ".

CHECK KEY SWITCH POWER SUPPLY CIRCUIT
1. Remove mechanical key from ignition switch.
2. Disconnect key switch and ignition knob switch connector.
3. Check voltage between key switch and ignition knob switch harness connector M12 terminal 3 and ground.
  3 - Ground : Battery voltage.
  
  Is the inspection result normal?
  
  YES: GO TO 2
  
  NO: Check harness between key switch and ignition knob switch and fuse.
  
  Fig 1: Checking Voltage Between Key Switch And Ignition Knob Switch Harness Connector M12 Terminal 3 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.

CHECK KEY SWITCH

Check continuity between key switch and ignition knob switch terminals 3 and 4.

CONTINUITY SPECIFICATION

Component	Terminals		Condition	Continuity
Ignition switch	3	4	Insert mechanical key into ignition switch.	Yes
Ignition switch	3	4	Remove mechanical key from ignition switch.	No

Is the inspection result normal?

YES: GO TO 3

NO: Replace key cylinder assembly (built-in key switch).

Fig 2: Checking Continuity Between BCM Harness Connector M18 Terminal 37 And Key Switch And Ignition Knob Switch Connector M12 Terminal 4

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

CHECK KEY SWITCH SIGNAL CIRCUIT
1. Disconnect BCM connector.
2. Check continuity between BCM harness connector M18 terminal 37 and key switch and ignition knob switch harness connector M12 terminal 4.
  37 - 4 : Continuity should exist.
3. Check continuity between BCM harness connector M18 terminal 37 and ground.
  37 - Ground : Continuity should not exist.
  
  Is the inspection result normal?
  
  YES: Key switch (BCM input) circuit is OK.
  
  NO: Repair or replace harness between key switch and ignition knob switch and BCM.
  
  Fig 3: Checking Continuity Between BCM Harness Connector M18 Terminal 37 And Key Switch And Ignition Knob Switch Harness Connector M12 Terminal 4
  Courtesy of NISSAN MOTOR CO., U.S.A.