2009 Infiniti QX56 AWDFACTORY OEM SERVICE PROCEDURE

Diagnosis Procedure

  1. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-I
    1. Turn ignition switch ON.
    2. Connect CONSULT-III and select "DATA MONITOR" mode.
    3. Select "LOAD SIGNAL" and check indication under the following conditions.
      LOAD SIGNAL INDICATION CONDITION

      Condition Indication
      Rear window defogger switch: ON ON
      Rear window defogger switch: OFF OFF

      OK or NG 

      OK: GO TO 2.

      NG: GO TO  4.

  2. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II

    Check "LOAD SIGNAL" indication under the following conditions.

    LOAD SIGNAL INDICATION CONDITION

    Condition Indication
    Heater fan control switch: ON ON
    Heater fan control switch: OFF OFF

    OK or NG 

    OK: GO TO 3.

    NG: GO TO  5.

  3. CHECK HEATER FAN SIGNAL CIRCUIT OVERALL FUNCTION

    Select "HEATER FAN SW" and check indication under the following conditions.

    HEATER FAN SIGNAL INDICATION CONDITION

    Condition Indication
    Lighting switch: ON at 2nd position ON
    Lighting switch: OFF OFF

    OK or NG 

    OK: INSPECTION END 

    NG: GO TO  6.

  4. CHECK REAR WINDOW DEFOGGER SYSTEM

    Refer to REAR WINDOW DEFOGGER SYSTEM .

    INSPECTION END 

  5. CHECK HEADLAMP SYSTEM

    Refer to HEADLAMP , or DAYTIME LIGHT SYSTEM .

    INSPECTION END 

  6. CHECK HEATER FAN CONTROL SYSTEM

    Refer to BLOWER MOTOR CONTROL SYSTEM .

    INSPECTION END 

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

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.