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Home >> Nissan-Datsun >> 2004 >> Quest SL >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System >> DTC P0122, P0123: TP Sensor >> Diagnostic Procedure
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Diagnostic Procedure

  1. CHECK GROUND CONNECTIONS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten ground three screws on the body. Refer to GROUND INSPECTION  .
      Fig 1: Checking Ground Connections
      G00775360Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 2.
    2. NG: Repair or replace ground connections.
  2. CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT 
    1. Disconnect electric throttle control actuator harness connector.
    2. Turn ignition switch ON.
      Fig 2: Disconnecting Electric Throttle Control Actuator Harness Connector
      G00775361Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between electric throttle control actuator terminal 1 and ground with CONSULT-II or tester.
      Fig 3: Checking Voltage Between Electric Throttle Control Actuator And Ground
      G00775362Courtesy of NISSAN MOTOR CO., U.S.A.
      1. Voltage: Approximately 5V 

    OK or NG 

    1. OK: GO TO 3.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  3. CHECK THROTTLE POSITION SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between ECM terminal 66 and electric throttle control actuator terminal 5. Refer to WIRING DIAGRAM  .
      1. Continuity should exist. 
    4. Also check harness for short to ground or short to power.

    OK or NG 

    1. OK: GO TO 4.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  4. CHECK THROTTLE POSITION SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Check harness continuity between ECM terminal 69 and electric throttle control actuator terminal 2. Refer to WIRING DIAGRAM  .
      1. Continuity should exist. 
    2. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK: GO TO 5.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  5. CHECK THROTTLE POSITION SENSOR 

    Refer to COMPONENT INSPECTION  .

    OK or NG 

    1. OK: GO TO  7 .
    2. NG: GO TO 6.
  6. 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  .
      1. INSPECTION END 
  7. CHECK INTERMITTENT INCIDENT 

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  .

    1. INSPECTION END