Communication Signal Circuit Check

WARNING: This page is about a different car, the 2004 Infiniti M45. However, it is still accessible from the selected car via links, so may be relevant.

Check Communication Signal
1. Turn ignition switch OFF.
2. Check the signal between malfunctioning door control unit connector and ground with oscilloscope.
  
  Fig 1: Checking Communication Signal
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 2: Terminals Connector Signal Chart
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: Communication signal is OK.
2. NG: Go to 2.
Check Communication Circuit
1. Disconnect driver door control unit (LCU01) and malfunctioning door control unit connector.
2. Check continuity between driver door control unit (LCU01) and malfunctioning door control unit connector.
  - Driver door control unit (LCU01) connector D8 terminal 5 and passenger door control unit connector D38 terminal 15.
    
    Fig 3: Checking Communication Circuit
    Courtesy of NISSAN MOTOR CO., U.S.A.
    1. 5 (L/Y) -15 (L/Y): Continuity should exist.
  - Driver door control unit (LCU01) connector D8 terminal 5 and rear LH door control unit connector D58 terminal 15.
    1. 5 (L/Y) -15 (L/Y): Continuity should exist.
  - Driver door control unit (LCU01) connector D8 terminal 5 and rear RH door control unit connector D78 terminal 15.
    1. 5 (L/Y) -15 (L/Y): Continuity should exist.
3. Check continuity between driver door control unit (LCU01) connector D8 terminal 5 and body ground.
  1. 5 (L/Y) - Ground: Continuity should not exist.
OK or NG
1. OK: Replace driver door control unit (LCU01).
2. NG: Repair or replace harness between driver door control unit (LCU01) and malfunctioning door control unit.