Vehicle Speed Signal Check for Display Control Unit

Is speedometer operated normally?

YES or NO 

1. YES : GO TO 2.
2. NO : Check combination meter trouble diagnosis. Refer to "TROUBLE DIAGNOSIS ".

1. Turn ignition switch OFF.
2. Disconnect display control unit connector and unified meter and A/C amp. connector.
3. Check continuity between display control unit harness connector M75 terminal 16 (R/G) and unified meter and A/C amp. harness connector M56 terminal 26 (R/G).
   1. Continuity should exist. 
4. Check continuity between display control unit harness connector M75 terminal 16 (R/G) and ground.
   1. Continuity should not exist. 

Fig 1: Checking Continuity Between Display Control Unit Harness Connector M75 Terminal 16 (R/G) And Ground

Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG 

1. OK : GO TO 3.
2. NG : Repair harness or connector.

1. Connect display control unit connector and unified meter and A/C amp. connector.
2. Start the engine.
3. Drive vehicle at a constant speed.
4. Check signal between display control unit harness connector M75 terminal 16 (R/G) and ground with CONSULT-II or oscilloscope.
   1. 16 (R/G) - Ground : Refer to " TERMINALS AND REFERENCE VALUE FOR DISPLAY CONTROL UNIT   ". 

Fig 2: Connecting Display Control Unit Connector And Unified Meter And A/C Amp

Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG 

1. OK : Replace display control unit.
2. NG : Check unified meter and A/C amp. system. Refer to "VEHICLE SPEED SIGNAL INSPECTION ".