2003 Infiniti M45FACTORY OEM SERVICE PROCEDURE

Encoder Switch Check (Passenger Side)

  1. CHECK FRONT POWER WINDOW REGULATOR (PASSENGER SIDE) POWER SUPPLY 
    1. Turn ignition switch ON.
    2. Check voltage between passenger door control unit connector D38 terminal 4 and ground.
      1. 4 (W) - Ground : Approx. 10V 
      3. Fig 1: Checking Front Power Window Regulator (Passenger Side) Power Supply
      G02023377Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK >> GO TO 2.

    NG >> Replace passenger door control unit.

  2. CHECK HARNESS CONTINUITY 
    1. Turn ignition switch OFF.
    2. Disconnect passenger door control unit and front power window regulator (passenger side) connector.
    3. Check continuity between driver door control unit (LCU01) connector D38 terminal 4 and front power window regulator (passenger side) connector D37 terminal 5.
      1. 4 (W) - 5 (W) : Continuity should exist. 
      4. Fig 2: Checking Harness Continuity
      G02023378Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK >> GO TO 3.

    NG >> Repair or replace harness between passenger door control unit and front power window regulator (passenger side).

  3. CHECK ENCODER GROUND 

    Check continuity between front power window regulator (passenger side) connector D37 terminal 3 and ground.

    1. 3 (B) - Ground : Continuity should exist. 
      2. Fig 3: Checking Encoder Ground
      G02023379Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK >> GO TO 4.

    NG >> Repair or replace harness.

  4. CHECK ENCODER SIGNAL 
    1. Connect passenger door control unit and front power window regulator (passenger side) connector.
    2. Turn ignition switch ON.
    3. Check the signal between passenger door control unit connector and ground with oscilloscope.
      Fig 4: Checking Encoder Signal
      G02023381Courtesy of NISSAN MOTOR CO., U.S.A.
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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.