FixVault

BCM Power Supply and Ground Circuit Check

WARNING: This page is about a different car, the 2004 Nissan Titan. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK FUSE 

    Check 50A fusible link (letter located in the fuse and fusible link box).

    Check 10A fuse (No. 59, located in the fuse and relay box).

    OK or NG 

    1. OK: GO TO 2.
    2. NG: If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse. Refer to
  2. CHECK POWER SUPPLY CIRCUIT 
    1. Turn ignition switch ON.
    2. Check voltage between BCM connector M18, M20 terminal 38, 70 and ground.

      38 (W/L) - Ground: Battery voltage 

      70 (W/B) - Ground: Battery voltage 

      Fig 1: Checking Voltage Between BCM Connector Terminal And Ground
      G03512344Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 3.
    2. NG: Repair or replace harness.
  3. CHECK GROUND CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect BCM.
    3. Check continuity between BCM connector M20 terminal 67 and ground.

      67 (B) - Ground: Continuity should exist. 

    OK or NG 

    1. OK: Power supply and ground circuit is OK.
    2. NG: Repair or replace harness.
Fig 2: Checking Continuity Between BCM Connector Terminal And Ground
G03512345Courtesy of NISSAN MOTOR CO., U.S.A.