Vehicle Speed Signal Check for Display Control Unit

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.

CHECK HARNESS
1. Turn ignition switch OFF.
2. Disconnect display control unit connector, combination meter connector, NAVI control unit connector and shift lock control unit connector.
3. Check continuity between display control unit harness connector M94 terminal 16 (W/R) and combination meter harness connector M24 terminal 29 (W/R).
  Continuity should exist.
4. Check continuity between display control unit harness connector M94 terminal 16 (W/R) and ground.
  Continuity should not exist.
  
  Fig 1: Checking Continuity Between Display Control Unit Harness Connector Terminal And Combination Meter Harness Connector Terminal
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : GO TO 2.
2. NG : Repair harness.
CHECK 1: VEHICLE SPEED SIGNAL
1. Connect display control unit connector.
2. Turn ignition switch ON.
3. Check voltage between display control unit harness connector M94 terminal 16 (W/R) and ground.
  Approx. 3.5V or more
  
  Fig 2: Checking Voltage Between Display Control Unit Harness Connector M94 Terminal 16 (W/R) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
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. Connect combination meter connector, NAVI control unit connector and shift lock control unit connector.
2. Drive vehicle at a constant speed.
3. Check signal between display control unit harness connector M94 terminal 16 (W/R) and ground with CONSULT-II or oscilloscope.
  16 (W/R) - Ground: Refer to , "TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
  
  Fig 3: Checking Signal Between Display Control Unit Harness Connector M94 Terminal 16 (W/R) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
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 .