2003 Infiniti Q45FACTORY OEM SERVICE PROCEDURE

Encoder Circuit Check (Rear LH or RH)

  1. CHECK REAR POWER WINDOW REGULATOR CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect rear power window regulator LH or RH connector.
    3. Turn ignition switch ON.
    4. Check voltage between rear power window regulator LH or RH connector D57(LH) or D77(RH) terminal 6 and ground.
      1. 6 (W) - Ground : Approx. 10V 
      Fig 1: Checking Voltage Between Rear Power Window Regulator LH Or RH Connector D57 (LH) Or D77 (RH) Terminal 6 And Ground
      G02045107Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG? 

    1. OK >> GO TO  3
    2. NG >> GO TO 2
  2. CHECK HARNESS CONTINUITY 
    1. Turn ignition switch OFF.
    2. Disconnect rear door control unit LH or RH and rear power window regulator LH or RH connector.
    3. Check continuity between rear door control unit LH or RH connector D58(LH) or D78(RH) terminal 15 and rear power window regulator LH or RH connector D57(LH) or D77(RH) terminal 6.
      1. 15 (W) - 6 (W) : Continuity should exist. 
      Fig 2: Checking Continuity Between Rear Door Control Unit LH Or RH Connector D58 (LH) Or D78 (RH) Terminal 15 And Rear Power Window Regulator LH Or RH Connector D57 (LH) Or D77 (RH) Terminal 6
      G02045108Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG? 

    1. OK >> Replace rear door control unit LH or RH.
    2. NG >> Repair or replace harness between rear door control unit LH or RH and rear power window regulator LH or RH.
  3. CHECK ENCODER GROUND 
    1. Turn ignition switch OFF.
    2. Disconnect rear power window regulator LH or RH connector.
    3. Check continuity between rear power window regulator LH or RH connector D57(LH) or D77(RH) terminal 4 and ground.
      1. 4 (B) - Ground : Continuity should exist. 
      Fig 3: Checking Continuity Between Rear Power Window Regulator LH Or RH Connector D57 (LH) Or D77 (RH) Terminal 4 And Ground
      G02045109Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG? 

    1. OK >> GO TO 4
    2. NG >> Repair or replace harness.
  4. CHECK ENCODER SIGNAL 
    1. Connect rear power window regulator LH or RH connector.
    2. Turn ignition switch ON.
    3. Check the signal between rear door control unit LH or RH connector and ground with oscilloscope.
      Fig 4: Signal Specifications Between Rear Door Control Unit LH Or RH Connector And Ground
      G02045110Courtesy 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.