Vehicle Speed Signal Check

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

CHECK HARNESS
1. Turn ignition switch OFF.
2. Disconnect display unit connector and unified meter and A/C amp. connector.
3. Check continuity between display unit harness connector M93 terminal 7 (BR) and unified meter and A/C amp. harness connector M50 terminal 26 (G).
  Continuity should exist.
4. Check continuity between display unit harness connector M93 terminal 7 (BR) and ground.
Continuity should not exist.

OK or NG
1. OK: GO TO 2.
2. NG: Repair harness.
  
  Fig 1: Checking Continuity Between Display Unit Harness Connector M93 Terminal 7 (BR) And Unified Meter And A/C Amp. Harness Connector M50 Terminal 26 (G) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK 1: VEHICLE SPEED SIGNAL
1. Connect display unit connector and unified meter and A/C amp. connector.
2. Turn ignition switch ON.
3. Check voltage between display unit harness connector M93 terminal 7 (BR) and ground.
Approx. 3.5V or more.

OK or NG
1. OK: GO TO 3.
2. NG " Replace display unit. Refer to CENTER STACK ASSEMBLY .
  
  Fig 2: Checking Voltage Between Display Unit Harness Connector M93 Terminal 7 (BR) And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK 2: VEHICLE SPEED SIGNAL
1. Drive vehicle at a constant speed.
2. Check the signal between display unit harness connector M93 terminal 7 (BR) and ground with CONSULT-II or oscilloscope.
1. 7 (BR) - Ground: Refer to "TERMINALS AND REFERENCE VALUE FOR DISPLAY UNIT ".
OK or NG
1. OK: Replace display unit. Refer to CENTER STACK ASSEMBLY .
2. NG: Check unified meter and A/C amp. system. Refer to VEHICLE SPEED SIGNAL INSPECTION .
  
  Fig 3: Checking Signal Between Display Unit Harness Connector M93 Terminal 7 (BR) And Ground With CONSULT-II Or Oscilloscope
  Courtesy of NISSAN MOTOR CO., U.S.A.