Check Key Switch (BCM Input)

WARNING: This page is about a different car, the 2005 Infiniti FX45 and 2005 Infiniti FX35. However, it is still accessible from the selected car via links, so may be relevant.

CHECK KEY SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition knob OFF position.
2. Disconnect key switch and ignition knob switch connector.
3. Check voltage between key switch and ignition knob switch connector M22 terminal 3 (L/R) and ground.
  1. 3 (L/R) - Ground : Battery voltage.
OK or NG
1. OK : GO TO 2.
2. NG : Check harness between key switch and ignition knob switch and fuse.
Fig 1: Checking Voltage Between Key Switch And Ignition Knob Switch Connector M22 Terminal 3 (L/R) And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK KEY SWITCH
Check continuity between key switch and ignition knob switch as follows.

Fig 2: Connector Terminal Reference Chart
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 3: Checking Continuity Between Key Switch And Ignition Knob Switch
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK : GO TO 3.
2. NG : Replace key switch and ignition knob switch.
CHECK KEY SWITCH SIGNAL CIRCUIT
1. Disconnect key switch and ignition knob switch connector and BCM connector.
2. Check continuity between key switch and ignition knob switch connector M22 terminal 4 (B/W) and BCM connector M3 terminal 37 (B/W).
  1. 4 (B/W) - 37 (B/W) : Continuity should exist.
3. Check continuity between key switch and ignition knob switch connector M22 terminal 4 (B/W) and ground.
  1. 4 (B/W) - Ground : Continuity should not exist.
OK or NG
1. OK : Key switch (BCM input) circuit is OK.
2. NG : Repair or replace harness between key switch and ignition knob switch and BCM.
Fig 4: Checking Key Switch Signal Circuit
Courtesy of NISSAN MOTOR CO., U.S.A.