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Home >> Infiniti >> 2004 >> QX56 AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System >> DTC P1124, P1126: Throttle Control Motor Relay >> Diagnostic Procedure
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Diagnostic Procedure

  1. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-I 
    1. Turn ignition switch OFF.
    2. Check voltage between ECM terminal 104 and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

    OK or NG

    OK: GO TO  4.

    NG: GO TO 2.

    Fig 1: Checking Voltage Between ECM Terminal 104 & Ground
    G02691579Courtesy of NISSAN MOTOR CO., U.S.A.
  2. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-II 
    1. Disconnect ECM harness connector.
    2. Disconnect IPDM E/R harness connector E122.
    3. Check 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 3.

    NG: Repair open circuit or short to ground or short to power in harness or connectors.

  3. CHECK FUSE 
    1. Disconnect 20A fuse.
    2. Check 20A fuse for blown.

    OK or NG

    OK: GO TO  7.

    NG: Replace 20A fuse.

  4. 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.
      CHECKING VOLTAGE CONDITION

      Ignition switch Voltage
      OFF Approximately 0V
      ON Battery voltage (11 - 14V)
      Fig 2: Checking Voltage Between ECM Terminal 3 & Ground
      G02691580Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    OK: GO TO  7.

    NG: GO TO 5.

  5. 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 E119.
    4. Check continuity between ECM terminal 3 and IPDM E/R terminal 6. 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  7.

    NG: GO TO 6.

  6. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E2, 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.

  7. CHECK INTERMITTENT INCIDENT 

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

    OK or NG

    OK: Replace IPDM E/R. Refer to FUSES & CIRCUIT BREAKERS .

    NG: Repair or replace harness or connectors.

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