Vehicle Speed Signal Check for Display Control Unit

WARNING: This page is about a different car, the 2006 Nissan Quest. 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 combination meter connector M24.
3. Check continuity between display control unit harness connector M94 terminal 16 and combination meter harness connector M24 terminal 14.
  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 & Combination Meter And Display Control Unit & Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 2.

NG: Repair harness.
CHECK 1: VEHICLE SPEED SIGNAL
1. Connect display control unit connector and combination meter connector.
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 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 2: VEHICLE SPEED SIGNAL
1. Drive vehicle at a constant speed.
2. Check signal between display control unit harness connector M94 terminal 16 and ground with CONSULT-II or oscilloscope.
  16 - Ground: Refer to , " TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT ".
Fig 3: Checking Signal Between Display Control Unit Harness Connector 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 combination meter system. Refer to , "VEHICLE SPEED SIGNAL INSPECTION ".