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 VEHICLE SPEED SIGNAL
1. Turn ignition switch ON.
2. Check signal between passenger seat control unit connector and body ground with oscilloscope.
Fig 1: Passenger Seat Control Unit Connector & Body Ground With Oscilloscope Specifications Table
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: Passenger Seat Control Unit Connector & Body Ground With Oscilloscope Signal Test
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
- OK : Replace passenger seat control unit.
- NG : GO TO 2.
CHECK VEHICLE SPEED SIGNAL CIRCUIT HARNESS
1. Turn ignition switch OFF.
2. Disconnect passenger seat control unit connector and unified meter and A/C amp.
3. Check continuity between passenger seat control unit connector B353 terminal 4 and unified meter and A/C amp. connector M49 terminal 34.
  - 4 (PU) - 34 (W/G) : Continuity should exist.
4. Check continuity between passenger seat control unit connector B353 terminal 4 and ground.
  - 4 (PU) - Ground : Continuity should not exist.
OK or NG
- OK : Vehicle speed signal circuit is OK. Further inspection is necessary. Refer to "VEHICLE SPEED SIGNAL INSPECTION ".
- NG : Repair or replace harness between passenger seat control unit and unified meter and A/C amp.
Fig 3: Passenger Seat Control Unit Connector B353 Terminal 4 & Ground Continuity Test
Courtesy of NISSAN MOTOR CO., U.S.A.