Vehicle Speed Signal Check for Display Control Unit

CHECK HARNESS
1. Turn ignition switch OFF.
2. Disconnect display control unit connector M94, combination meter connector M24 and NAVI control unit connector B152.
3. Check continuity between display control unit harness connector M94 terminal 16 and combination meter harness connector M24 terminal 29.
  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 Connector M94 Terminal 16 And Ground
OK or NG

OK: GO TO 2.

NG: Repair harness.
CHECK 1: VEHICLE SPEED SIGNAL
1. Connect display control unit 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 Connector M94 Terminal 16 And Ground
OK or NG

OK: GO TO 3.

NG: Replace display control unit. Refer to "DISPLAY CONTROL UNIT ".
CHECK 2: VEHICLE SPEED SIGNAL
1. Connect combination meter connector M24 and NAVI control unit connector B152.
2. Drive vehicle at a constant speed.
3. 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 Connector M94 Terminal 16 And Ground
OK or NG

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

NG: Check combination meter system. Refer to "VEHICLE SPEED SIGNAL INSPECTION ".