Vehicle Speed Signal Check for Display Control Unit

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

CHECK VEHICLE SPEED OPERATION
Does speedometer operate normally?

Yes or No
1. YES: GO TO 2.
2. NO: Check combination meter trouble diagnosis. Refer to "DIAGNOSIS FLOW ".
CHECK HARNESS
1. Turn ignition switch OFF.
2. Disconnect display control unit connector, unified meter and A/C amp. connector, NAVI control unit connector, combination meter connector and audio unit connector.
3. Check continuity between display control unit harness connector M42 terminal 16 (V/W) and unified meter and A/C amp. harness connector M50 terminal 26 (V/W).
  Continuity should exist.
4. Check continuity between display control unit harness connector M42 terminal 16 (V/W) and ground.
  Continuity should not exist.
  
  Fig 1: Checking Continuity Between Display Control Unit Harness Connector And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 3.
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 M42 terminal 16 (V/W) and ground.
  Approx. 5V
  
  Fig 2: Checking Voltage Between Display Control Unit Harness Connector And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 4.
2. NG: Replace display control unit.
CHECK 2: VEHICLE SPEED SIGNAL
1. Turn ignition switch OFF.
2. Connect unified meter and A/C amp. connector, NAVI control unit connector, combination meter connector and audio unit connector.
3. Drive vehicle at a constant speed.
4. Check signal between display control unit harness connector M42 terminal 16 (V/W) and ground with CONSULT-II or oscilloscope.
  16 (V/W) - Ground: Refer to " TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
  
  Fig 3: Checking Signal Between Display Control Unit Harness Connector And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: Replace display control unit.
2. NG: Replace unified meter and A/C amp. Refer to "REMOVAL AND INSTALLATION OF UNIFIED METER AND A/C AMP ".