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Home >> Nissan-Datsun >> 2005 >> Altima Base >> Repair and Diagnosis >> Engine Performance >> Engine Control System - Qr25DE >> DTC P1122: Electric Throttle Control Function >> 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: Locating Ground Connections
      G02525254Courtesy 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 RELAY INPUT SIGNAL CIRCUIT-I 
    1. Check voltage between ECM terminal 3 and ground under the following conditions with CONSULT-II or tester.
      ECM TERMINAL VOLTAGE CONDITIONS

      Ignition switch Voltage
      OFF Approximately 0V
      ON Battery voltage (11 -14V)
      Fig 2: Checking Voltage Between ECM Terminal 3 And Ground With CONSULT-II Or Tester
      G02525255Courtesy of NISSAN MOTOR CO., U.S.A.

      OK or NG

      • OK: GO TO  10.
      • NG: GO TO 3.
  3. CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT-II 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Disconnect IPDM E/R harness connector E124.
    4. Check continuity between ECM terminal 3 and IPDM E/R terminal 42.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

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

      OK or NG

      • OK: GO TO  5.
      • NG: GO TO 4.
  4. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E20, F32
    • Harness for open or short between ECM and IPDM E/R
      • : Repair open circuit or short to ground or short to power in harness or connectors.
  5. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-I 
    1. Reconnect all harness connectors disconnected.
    2. Check voltage between ECM terminal 104 and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

      OK or NG

      • OK: GO TO  9.
      • NG: GO TO 6.
      Fig 3: Checking Voltage Between ECM Terminal 104 And Ground With CONSULT-II Or Tester
      G02525256Courtesy of NISSAN MOTOR CO., U.S.A.
  6. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-II 
    1. Disconnect ECM harness connector.
    2. Disconnect IPDM E/R harness connector E121.
    3. Check harness continuity between ECM terminal 104 and IPDM E/R terminal 47.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

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

      OK or NG

      • OK: GO TO  8.
      • NG: GO TO 7.
  7. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E19, F33
    • Harness for open or short between ECM and IPDM E/R
      • : Repair open circuit or short to ground or short to power in harness or connectors.
  8. CHECK FUSE 
    1. Disconnect 10A fuse.
    2. Check 10A fuse for blown.

      OK or NG

      • OK: GO TO 9.
      • NG: Replace 15A fuse.
  9. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    OK or NG

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

      Refer to WIRING DIAGRAM .

      Fig 4: Electric Throttle Control Actuator Terminals Continuity
      G02525257Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 5: Locating Electric Throttle Control Actuator
      G02525258Courtesy of NISSAN MOTOR CO., U.S.A.
    5. Also check harness for short to ground and short to power.

      OK or NG

      • OK: GO TO 11.
      • NG: Repair or replace.
  11. 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.

      OK or NG

      • OK: GO TO 12.
      • NG: Remove the foreign matter and clean the electric throttle control actuator inside.
      Fig 6: Locating Electric Throttle Control Actuator
      G02525259Courtesy of NISSAN MOTOR CO., U.S.A.
  12. CHECK THROTTLE CONTROL MOTOR 

    Refer to "COMPONENT INSPECTION ".

    OK or NG

    • OK: GO TO 13.
    • NG: GO TO  14.
  13. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    OK or NG

    • OK: GO TO 14.
    • NG: Repair or replace harness or connectors.
  14. 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 
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