Vehicle Speed Signal Check

WARNING: This page is about a different car, the 2005 Nissan 350Z. However, it is still accessible from the selected car via links, so may be relevant.

CHECK SPEEDOMETER FUNCTION
Does speedometer is operated normally?

Yes or No
- Yes : GO TO 2.
- No : Check combination meter trouble diagnosis. Refer to "VEHICLE SPEED SIGNAL INSPECTION " in "COMBINATION METERS".
CHECK HARNESS
1. Turn ignition switch OFF.
2. Disconnect NAVI control unit connector and unified meter and A/C amp. connector.
3. Check continuity between NAVI control unit harness connector B 105 terminal 28 (L/B) and unified meter and A/C amp. harness connector M49 terminal 34 (W/G).
  - 28 - 34 : Continuity should exist.
4. Check continuity between NAVI control unit harness connector B 105 terminal 28 (L/B) and ground.
  - 28 - Ground : Continuity should not exist.
  Fig 1: NAVI Control Unit Harness Connector B 105 Terminal 28 (L/B) & Ground Continuity Test
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK : GO TO 3.
- NG : Repair harness or connector.
CHECK NAVI CONTROL UNIT
1. Connect NAVI control unit connector.
2. Turn ignition switch ON.
3. Check voltage between NAVI control unit harness connector B 105 terminal 28 (L/B) and ground.
  - 28 - Ground : Approx. 5V
OK or NG
- OK : GO TO 4.
- NG : Replace NAVI control unit.
Fig 2: NAVI Control Unit Harness Connector B 105 Terminal 28 (L/B) & Ground Voltage Test
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK VEHICLE SPEED SIGNAL
1. Turn ignition switch OFF.
2. Connect unified meter and A/C amp. connector.
3. Start engine and drive vehicle at more than 40 km/h (25MPH).
4. Check signal between NAVI control unit harness connector B 105 terminal 28 (L/B) and ground with CONSULT-II or oscilloscope.
  - 28 - Ground : Refer to "TERMINALS AND REFERENCE VALUE FOR NAVI CONTROL UNIT ".
  Fig 3: NAVI Control Unit Harness Connector B 105 Terminal 28 (L/B) & Ground Signal Test
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK : INSPECTION END
- NG : Replace unified meter and A/C amp. Refer to "REMOVAL AND INSTALLATION OF UNIFIED METER AND A/C AMP ".