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Home >> Infiniti >> 2004 >> I35 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System >> DTC P1122: Electric Throttle Control Function >> Diagnostic Procedure
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Diagnostic Procedure

  1. RETIGHTEN GROUND SCREWS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten engine ground screws. See Figure .
    1. : GO TO 2
  2. CHECK THROTTLE CONTROL MOTOR GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Disconnect ECM harness connector.
    2. Check harness continuity between ECM terminal 107 and engine ground.

      Refer to Wiring Diagram.

      Continuity should exist. 

    3. Also check harness for short to power.

    OK or NG 

    1. OK: GO TO 3.
    2. NG: Repair open circuit or short to power in harness or connectors.
  3. CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-I 
    1. Reconnect harness connector disconnected.
    2. Check voltage between ECM terminal 102 and ground under the following conditions with CONSULT-II or tester.
      Fig 1: Display Ignition Switch Position And Voltage
      G00787044Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO  12 .
    2. NG: GO TO 4.
  4. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect throttle control motor relay.
      Fig 2: Disconnecting Throttle Control Motor Relay
      G00787045Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between throttle control motor relay terminals 2, 5 and ground with CONSULT-II or tester.
      Fig 3: Checking Voltage Between Throttle Control Motor Relay Terminals 2, 5 And Ground
      G00787046Courtesy of NISSAN MOTOR CO., U.S.A.

    Voltage: Battery voltage 

    OK or NG 

    1. OK: GO TO  6 .
    2. NG: GO TO 5.
  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • 15A fuse
    • Harness for open and short between throttle control motor relay and fuse
    1. : Repair open circuit or short to ground or short to power in harness or connectors.
  6. CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-II 
    1. Disconnect ECM harness connector.
    2. Check harness continuity between ECM terminal 102 and throttle control motor relay terminal 3.

      Refer to Wiring Diagram.

      Continuity should exist. 

    3. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK: GO TO  8 .
    2. NG: GO TO 7.
  7. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connector E15, F18
    • Harness for open and short between throttle control motor relay and ECM
    1. : Repair open circuit or short to ground or short to power in harness or connectors.
  8. CHECK THROTTLE CONTROL MOTOR RELAY OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Check harness continuity between ECM terminal 26 and throttle control motor relay terminal 1.

      Refer to Wiring Diagram.

      Continuity should exist. 

    2. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK: GO TO  10 .
    2. NG: GO TO 9.
  9. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connector E81, M15
    • Harness connectors M223, F53
    • Harness for open and short between throttle control motor relay and ECM
    1. : Repair open circuit to short to ground or short to power in harness or connectors.
  10. CHECK THROTTLE CONTROL MOTOR RELAY 

    Refer to COMPONENT INSPECTION  .

    OK or NG 

    1. OK: GO TO 11.
    2. NG: Replace throttle control motor relay.
  11. CHECK INTERMITTENT INCIDENT 

    Perform TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  .

    1. : INSPECTION END 
  12. CHECK THROTTLE CONTROL MOTOR OUTPUT SIGNAL CIRCUIT FOR OPEN OR SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect electric throttle control actuator harness connector. See Figure .
    3. Disconnect ECM harness connector.
    4. Check harness continuity between the following terminals.

      Refer to Wiring Diagram.

      Fig 4: Displaying Terminal And Harness Continuity
      G00787048Courtesy of NISSAN MOTOR CO., U.S.A.
    5. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK: GO TO 13.
    2. NG: Repair or replace.
  13. CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY 
    1. Remove the intake air duct.
    2. Check if foreign matter is caught between the throttle valve and the housing. See Figure .

    OK or NG 

    1. OK: GO TO 14.
    2. NG: Remove the foreign matter and clean the electric throttle control actuator inside.
  14. CHECK THROTTLE CONTROL MOTOR 

    Refer to COMPONENT INSPECTION  .

    OK or NG 

    1. OK: GO TO 15.
    2. NG: GO TO  16 .
  15. CHECK INTERMITTENT INCIDENT 

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  .

    OK or NG 

    1. OK: GO TO 16.
    2. NG: Repair or replace harness or connectors.
  16. 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 
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