2004 Infiniti QX56 AWDFACTORY OEM SERVICE PROCEDURE

Diagnostic Procedure

  1. CHECK GROUND CONNECTIONS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten ground three screws on the body.
      Fig 1: Locating Body Ground
      G02691567Courtesy of NISSAN MOTOR CO., U.S.A.

      Refer to GROUND INSPECTION .

    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.
      CHECKING VOLTAGE CONDITION

      Ignition switch Voltage
      OFF Approximately 0V
      ON Battery voltage (11 - 14V)

    OK or NG

    OK: GO TO  9.

    NG: GO TO 3.

    Fig 2: Checking Voltage Between ECM Terminal 3 & Ground
    G02691568Courtesy of NISSAN MOTOR CO., U.S.A.
  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 E119.
    4. Check harness 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  5.

    NG: GO TO 4.

  4. 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.

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

      Voltage: Battery voltage 

    OK or NG

    OK: GO TO  8.

    NG: GO TO 6.

    Fig 3: Checking Voltage Between ECM Terminal 104 & Ground
    G02691569Courtesy 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 E122.
    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 7.

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

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

    OK or NG

    OK: GO TO 8.

    NG: Replace 20A fuse.

  8. 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.

  9. 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: Throttle Control Motor Output Signal Circuit Continuity Table
      G02691570Courtesy of NISSAN MOTOR CO., U.S.A.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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