2009 Infiniti QX56 AWDFACTORY OEM SERVICE PROCEDURE

Diagnosis Procedure

  1. CHECK POWER SUPPLY CIRCUIT
    1. Turn ignition switch OFF.
    2. Disconnect IPDM E/R harness connector E120.
    3. Check voltage between IPDM E/R terminal 22 and ground with CONSULT-III or tester.

      Voltage: Battery voltage 

      OK or NG 

      OK: GO TO  3.

      NG: GO TO 2.

      Fig 1: Checking Voltage Between IPDM E/R Terminal 22 And Ground
      G06315837Courtesy of NISSAN MOTOR CO., U.S.A.
  2. DETECT MALFUNCTIONING PART

    Check the following.

    • 40A fusible link
    • Harness for open or short between IPDM E/R and battery

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

  3. CHECK COOLING FAN MOTOR CIRCUIT FOR OPEN OR SHORT
    1. Disconnect cooling fan motor harness connector (1).
    2. Check harness continuity between cooling fan motor terminal 2 and IPDM E/R terminal 24, cooling fan motor terminal 1 and ground.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

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

      OK or NG 

      OK: GO TO 4.

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

      Fig 2: Identifying Cooling Fan Motor Harness Connector
      G06315838Courtesy of NISSAN MOTOR CO., U.S.A.
  4. CHECK COOLING FAN MOTOR

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO 5.

    NG: Replace cooling fan motor.

  5. CHECK INTERMITTENT INCIDENT

    Perform "HOW TO CHECK TERMINAL " and "INTERMITTENT INCIDENT ".

    OK or NG 

    OK: Replace IPDM E/R. Refer to "REMOVAL AND INSTALLATION OF IPDM E/R ".

    NG: Repair or replace harness connectors.

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.