Vehicle Speed Signal Check for Display Control Unit

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

CHECK HARNESS
1. Turn ignition switch OFF.
2. Disconnect display control unit connector M94, NAVI control unit connector P107 and combination meter connector M24.
3. Check continuity between display control unit harness connector M94 terminal 16 (P/L) and combination meter harness connector M24 terminal 14 (P/L).
  
  Fig 1: Checking Continuity Between Connector M94 Terminal 16 And Connector M24 Terminal 14 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Continuity should exist.
4. Check continuity between display control unit harness connector M94 terminal 16 (P/L) and ground.
  Continuity should not exist.
OK or NG
1. OK: GO TO 2.
2. NG: Repair harness.
CHECK 1: VEHICLE SPEED SIGNAL
1. Connect display control unit connector, NAVI control unit connector and combination meter connector.
2. Turn ignition switch ON.
3. Check voltage between display control unit harness connector M94 terminal 16 (P/L) and ground.
  
  Fig 2: Checking Voltage Between Terminal 16 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Approx. 3.5V or more
OK or NG
1. OK: GO TO 3.
2. NG: Replace display control unit. Refer to "REMOVAL AND INSTALLATION OF DISPLAY CONTROL UNIT ".
CHECK 2: VEHICLE SPEED SIGNAL
1. Drive vehicle at a constant speed.
2. Check signal between display control unit harness connector M94 terminal 16 (P/L) and ground with CONSULT-II or oscilloscope.
  
  Fig 3: Checking Signal Between Terminal 16 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  16 (P/L) - Ground: Refer to " TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
OK or NG
1. OK: Replace display control unit. Refer to "REMOVAL AND INSTALLATION OF DISPLAY CONTROL UNIT ".
2. NG: Check combination meter system. Refer to "VEHICLE SPEED SIGNAL INSPECTION ".