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Home >> Lexus >> 2025 >> NX 350h >> Repair and Diagnosis >> External Pages >> Different car >> Section 71 (Heating / Air Conditioning System - Diagnostic Codes, Circuit Tests & Symptom Tests) >> AIR CONDITIONING SYSTEM (for Gasoline Model) >> DTC B1403-7F: Front Air Outlet Damper Control Servo Motor Actuator Stuck Off [11/2021 - ] >> Procedure

DTC B1403-7F: Front Air Outlet Damper Control Servo Motor Actuator Stuck Off [11/2021 - ]: Procedure

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  1. CHECK NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (INSTALLATION CONDITION) 
    1. Check that the No. 1 air conditioning radiator damper servo sub-assembly is installed correctly.

      Refer to REASSEMBLY [11/2021 - ]

      OK

      No. 1 air conditioning radiator damper servo sub-assembly is installed correctly.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REINSTALL NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY. Refer to  REASSEMBLY [11/2021 - ] 

    Result: 

    OK 

    See step  2

  2. CHECK NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (MOTOR, LINK, DAMPER) 
    1. Check for a wire harness caught between the links of the motors and dampers.

      OK

      No wire harnesses are caught between the links of the motors and dampers.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REMOVE PINCHED WIRE HARNESS 

    Result: 

    OK 

    See step  3

  3. CHECK AIR CONDITIONING RADIATOR ASSEMBLY (DAMPER) 
    1. Remove the No. 1 air conditioning radiator damper servo sub-assembly.

      Refer to DISASSEMBLY [11/2021 - ]

    2. Operate the dampers by hand.

      OK

      The dampers are easily operated by hand.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY. Refer to  REASSEMBLY [11/2021 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE AIR CONDITIONING RADIATOR ASSEMBLY. Refer to  REMOVAL [11/2021 - 03/2022]  , or refer to  REMOVAL [03/2022 - ]