Diagnostic Procedure

WARNING: This page is about a different car, the 2005 Infiniti QX56. However, it is still accessible from the selected car via links, so may be relevant.

CHECK CONNECTOR
1. Disconnect BCM harness connectors M18 and M20.
2. Check terminals for damage or loose connections.
Inspection results OK?
1. OK: GO TO 2.
2. NG: Repair or replace damaged parts.
CHECK POWER SUPPLY CIRCUIT (BAT)
Check voltage between BCM harness connector M20 terminal 70 (W/B) and ground.

Fig 1: Checking Voltage Between BCM Harness Connector M20 Terminal 70 & Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: Terminal Voltage Specification Chart
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: GO TO 3.
2. NG: Check BCM power supply circuit for open or short.
CHECK POWER SUPPLY CIRCUIT (IGN)
1. Turn ignition switch ON.
2. Check voltage between BCM harness connector M18 terminal 38 (W/L) and ground.
  
  Fig 3: Checking Voltage Between BCM Harness Connector M18 Terminal 38 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 4: Terminal Voltage Specification Chart
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 4.
2. NG: Check BCM power supply circuit for open or short.
CHECK GROUND CIRCUIT
Check continuity between BCM harness connector M20 terminal 67 (B) and ground.

Fig 5: Checking Continuity Between BCM Harness Connector M20 Terminal 67 & Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 6: Continuity Specification Chart
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: Replace BCM. Refer to "REMOVAL AND INSTALLATION OF BCM ".
2. NG: Repair BCM ground circuit.