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Home >> Infiniti >> 2008 >> QX56 RWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - DTCS P1148 To P2A03 >> DTC P2118: Throttle Control Motor >> Diagnosis Procedure
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Diagnosis 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: Identifying Body Ground Screw
      G05739671Courtesy 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 (1) harness connector.
      • Illustration shows the view with intake air duct removed.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between the following terminals.

      Refer to WIRING DIAGRAM .

      CONTINUITY REFERENCE CHART

      Electric throttle control actuator terminal ECM terminal Continuity
      5 5 Should not exist
      4 Should exist
      6 5 Should exist
      4 Should not exist
    4. Also check harness for short to ground and short to power.
      Fig 2: Identifying Electric Throttle Control Actuator
      G05739672Courtesy of NISSAN MOTOR CO., U.S.A.

    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 "HOW TO CHECK TERMINAL " and "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