Vehicle Speed Signal Inspection

Symptom: Indication is irregular for the speedometer and odo/trip meter.

1. CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) SELF-DIAGNOSIS 

   Preform the ABS actuator and electric unit (control unit) self-diagnosis. Refer to "CONSULT-II FUNCTIONS ".

   Self-diagnostic results content 

   1. No malfunction detected:GO TO 2.
   2. Malfunction detected:Check applicable parts, and repair or replace corresponding parts.
2. CHECK UNIFIED METER AND A/C AMP. OUTPUT SIGNAL 
   1. Start engine and drive vehicle at approximately 40 km/h (25 MPH).
   2. Check voltage signal between unified meter and A/C amp. harness connector M56 terminal 26 (R/G) and ground.
      NOTE: Maximum voltage may be 5 V due to specifications (connected units).
      1. 26 (R/G) - Ground: 
   Fig 1: Voltage Signal Waveform

   Courtesy of NISSAN MOTOR CO., U.S.A.
   Fig 2: Checking Voltage Signal Between Terminal 26 And Ground

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

   OK or NG 

   1. OK: GO TO 3.
   2. NG :
      • If monitor indicates "0 V" constantly, repair or replace malfunctioning parts after checking each unit inputting vehicle speed signal (8 pulse), harness and connector between each unit and unified meter and A/C amp.
      • If monitor indicates "5 V" or "12 V" constantly, replace unified meter and A/C amp. Refer to "REMOVAL AND INSTALLATION OF UNIFIED METER AND A/C AMP. ".
3. CHECK CONTINUITY BETWEEN COMBINATION METER AND UNIFIED METER AND A/C AMP. 
   1. Turn ignition switch OFF.
   2. Disconnect combination meter connector and unified meter and A/C amp. connector.
   3. Check continuity between combination meter harness connector M20 terminal 1 (R/G) and unified meter and A/C amp. harness connector M56 terminal 26 (R/G).
      1. 1 (R/G) - 26 (R/G): Continuity should exist. 

   OK or NG 

   1. OK: Replace combination meter.
   2. NG: Repair harness or connector.
   Fig 3: Checking Continuity Between Terminal 1 And Terminal 26

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