Vehicle Speed Signal Inspection

CHECK HARNESS
1. Turn ignition switch OFF.
2. Disconnect AV control unit connector and combination meter connector.
3. Check continuity between AV control unit harness connector M77 terminal 33 and combination meter harness connector M41 terminal 17.
  33 - 17 : Continuity should exist.
4. Check continuity between AV control unit harness connector M77 terminal 33 and ground.
  33 - Ground : Continuity should not exist.
OK or NG
1. OK : GO TO 2.
2. NG : Repair harness or connector.
  
  Fig 1: Identifying Continuity Between AV Control Unit Harness Connector M77 Terminal 33 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK OUTPUT VOLTAGE
1. Connect AV control unit connector.
2. Turn ignition switch ON.
3. Check voltage between AV control unit harness connector M77 terminal 33 and ground.
  33 - Ground : Approx. 3.5 V or more
OK or NG
1. OK : GO TO 3.
2. NG : Replace AV control unit.
  
  Fig 2: Identifying Voltage Between AV Control Unit Harness Connector M77 Terminal 33 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK VEHICLE SPEED SIGNAL
1. Turn ignition switch OFF and connect combination meter connector.
2. Start engine and drive vehicle at approximately 40 km/h (25 MPH).
3. Check voltage signal between AV control unit harness connector M77 terminal 33 and ground.
  33 - Ground
  
  Fig 3: Voltage Waveform Pattern
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 4: Identifying Voltage Signal Between AV Control Unit Harness Connector M77 Terminal 33 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : Replace AV control unit.
2. NG : Check combination meter. Refer to "VEHICLE SPEED SIGNAL INSPECTION ".