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Home >> Nissan-Datsun >> 2005 >> Quest Base >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> DTC P1128: Throttle Control Motor >> Diagnostic Procedure
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Diagnostic Procedure

  1. CHECK GROUND CONNECTIONS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten three ground screws on the body. Refer to "GROUND INSPECTION ".
      Fig 1: Loosening & Retightening Ground Screws
      G02474278Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    • OK: GO TO 2.
    • NG: Repair or replace ground connections.
  2. CHECK THROTTLE CONTROL MOTOR OUTPUT SIGNAL CIRCUIT FOR OPEN OR SHORT 
    1. Disconnect electric throttle control actuator harness connector.
    2. Disconnect ECM harness connector.
      Fig 2: Terminals Continuity Condition Chart
      G02474279Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 3: Disconnecting Electric Throttle Control Actuator Harness Connector
      G02474280Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check harness continuity between the following terminals. Refer to WIRING DIAGRAM .
    4. Also check harness for short to ground and short to power.

    OK or NG

    • OK: GO TO 3.
    • NG: Repair or replace.
  3. CHECK THROTTLE CONTROL MOTOR 

    Refer to "COMPONENT INSPECTION ".

    OK or NG

    • OK: GO TO 4.
    • NG: GO TO  5.
  4. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    OK or NG

    • OK: GO TO 5.
    • NG: Repair or replace harness or connectors.
  5. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR 
    1. Replace the electric throttle control actuator.
    2. Perform "THROTTLE VALVE CLOSED POSITION LEARNING ".
    3. Perform "IDLE AIR VOLUME LEARNING ".
    • INSPECTION END