Vehicle Speed Signal Inspection

WARNING: This page is about a different car, the 2006 Infiniti G35. However, it is still accessible from the selected car via links, so may be relevant.

CHECK VEHICLE SPEED OPERATION
Does speed meter operate normally?

YES or NO
1. YES : GO TO 2.
2. NO : Check combination meter trouble diagnosis. Refer to "SELF-DIAGNOSIS MODE OF COMBINATION METER ".
CHECK HARNESS
1. Turn ignition switch OFF.
2. Disconnect NAVI control unit connector and combination meter connector.
3. Check continuity between NAVI control unit harness connector (A) M58 terminal 66 and combination meter harness connector (B) M19 terminal 14.
  66 - 14 : Continuity should exist.
4. Check continuity NAVI control unit harness connector (A) M58 terminal 66 and ground.
  66 - Ground : Continuity should not exist.
  
  Fig 1: Identifying Continuity NAVI Control Unit Harness Connector (A) M58 Terminal 66 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : GO TO 3.
2. NG :
  - Check harness for open or short between NAVI control unit and combination meter.
  - Check connector housings for disconnected or loose terminals.
CHECK VEHICLE SPEED SIGNAL
1. Connect NAVI control unit connector and combination meter connector.
2. Drive vehicle at a constant speed of 40km/h (25MPH).
3. Check the signal between NAVI control unit harness connector M58 terminal 66 and ground with CONSULT-II or oscilloscope.
  66 - Ground : Refer to "TERMINALS AND REFERENCE VALUE FOR NAVI CONTROL UNIT "
  
  Fig 2: Identifying Signal Between NAVI Control Unit Harness Connector M58 Terminal 66 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : Replace NAVI control unit.
2. NG : Check combination meter system. Refer to "SELF-DIAGNOSIS MODE OF COMBINATION METER ".