Vehicle Speed Signal Check for Display Control Unit

WARNING: This page is about a different car, the 2008 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 control unit connector M94 and unified meter and A/C amp. connector M50.
3. Check continuity between display control unit harness connector M94 terminal 16 and unified meter and A/C amp. harness connector M50 terminal 26.
  Continuity should exist.
4. Check continuity between display control unit harness connector M94 terminal 16 and ground.
  Continuity should not exist.
Fig 1: Checking Continuity Between Display Control Unit Harness Connector M94 Terminal 16 And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 2.

NG: Repair harness.
CHECK VEHICLE SPEED SIGNAL (VEHICLE PARKED)
1. Connect display control unit connector M94 and unified meter and A/C amp. connector M50.
2. Turn ignition switch ON.
3. Check voltage between display control unit harness connector M94 terminal 16 and ground.
  Approx. 3.5V or more
Fig 2: Checking Voltage Between Display Control Unit Connector M94 Terminal 16 And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 3.

NG: Replace display control unit. Refer to "DISPLAY CONTROL UNIT ".
CHECK VEHICLE SPEED SIGNAL (VEHICLE MOVING)
1. Drive vehicle at a constant speed.
2. Check signal between display control unit harness connector M94 terminal 16 and ground with CONSULT-III or oscilloscope.
  16 - Ground: Refer to "TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
Fig 3: Checking Signal Between Display Control Unit Connector M94 Terminal 16 And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: Replace display control unit. Refer to "DISPLAY CONTROL UNIT ".

NG: Check unified meter and A/C amp. system. Refer to "VEHICLE SPEED SIGNAL INSPECTION ".