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Home >> Lexus >> 2020 >> UX 200 Luxury >> Repair and Diagnosis >> External Pages >> Different car >> Section 60 (Air Conditioning System - Diagnostic Codes (1 Of 2) (Hybrid)) >> AIR CONDITIONING SYSTEM (for HV Model) >> DTC B1442: Air Inlet Damper Control Servo Motor [10/2018 - ] >> Procedure

DTC B1442: Air Inlet Damper Control Servo Motor [10/2018 - ]: Procedure

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / Air Conditioner / Trouble Codes.
    5. Check for DTCs.

      Body Electrical > Air Conditioner > Trouble Codes 

      Result

      Result Proceed to
      Only B1497 is output A
      B1441, B1442, B1443 and B1446 are output B
      Only B1442 is output C

    Result: 

    A 

    GO TO DTC B1497. Refer to  DTC B1497: Communication Malfunction (Bus Ic) [10/2018 - 10/2020]  , or refer to  DTC B1497: Communication Malfunction (Bus Ic) [10/2020 - ]  

    Result: 

    B 

    REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY. Refer to  DISASSEMBLY [10/2018 - 10/2020]  , or refer to  DISASSEMBLY [10/2020 - ] 

    Result: 

    C 

    See step  2

  2. INSPECT NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY (INSTALLATION CONDITION) 
    1. Check that the No. 1 blower damper servo sub-assembly is installed correctly.

      OK

      The No. 1 blower damper servo sub-assembly is installed correctly.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    INSTALL NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY. Refer to  REASSEMBLY [10/2018 - ] 

    Result: 

    OK 

    See step  3

  3. INSPECT NO. 1 BLOWER 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  4

  4. INSPECT BLOWER ASSEMBLY (DAMPER) 
    1. Remove the blower assembly.

      Refer to DISASSEMBLY [10/2018 - ]

    2. Operate the air inlet dampers by hand.

      OK

      The air inlet dampers are easily operated by hand.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE BLOWER ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022]  , or refer to  REMOVAL [07/2022 - ] 

    Result: 

    OK 

    See step  5

  5. INSPECT AIR CONDITIONING HARNESS ASSEMBLY 
    1. Disconnect the No. 1 air conditioning radiator damper servo sub-assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A-6 (STE2) - B-3 (sigB) Always Below 1 Ω
      A-5 (STE1) - B-2 (sigA) Always Below 1 Ω
      A-8 (M-) - B-5 (M-) Always Below 1 Ω
      A-7 (M+) - B-4 (M+) Always Below 1 Ω
      A-4 (GND) - B-1 (GND) Always Below 1 Ω
      A-6 (STE2) or B-3 (sigB) - Other terminals and Body ground Always 10 kΩ or higher
      A-5 (STE1) or B-2 (sigA) - Other terminals and Body ground Always 10 kΩ or higher
      A-8 (M-) or B-5 (M-) - Other terminals and Body ground Always 10 kΩ or higher
      A-7 (M+) or B-4 (M+) - Other terminals and Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY. Refer to  DISASSEMBLY [10/2018 - 10/2020]  , or refer to  DISASSEMBLY [10/2020 - ] 

    Result: 

    OK 

    See step  6

  6. PERFORM ACTIVE TEST USING TECHSTREAM 
    1. Connect the No. 1 air conditioning radiator damper servo sub-assembly connector.
    2. Remove the No. 2 air conditioning radiator damper servo sub-assembly.

      Refer to DISASSEMBLY [10/2018 - 10/2020] , or refer to DISASSEMBLY [10/2020 - ]

    3. Connect the No. 1 blower damper servo sub-assembly connector to the No. 2 air conditioning radiator damper servo sub-assembly.
    4. Connect the Techstream to the DLC3.
    5. Turn the power switch on (IG).
    6. Turn the Techstream on.
    7. Enter the following menus: Body Electrical / Air Conditioner / Active Test.
    8. Perform the Active Test according to the display on the Techstream.

      Body Electrical > Air Conditioner > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      Air Inlet Damper Targ Pulse No. 1 blower damper servo sub-assembly pulse* Min.: 128
      Max.: 383      		 Operates between 220 and 256 pulses
      1. *: Though this Active Test is for the No. 1 blower damper servo sub-assembly, in this case it is used to check the operation of the No. 2 air conditioning radiator damper servo sub-assembly.

      Body Electrical > Air Conditioner > Active Test 

      Tester Display
      Air Inlet Damper Targ Pulse

      OK

      The No. 2 air conditioning radiator damper servo sub-assembly operates.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY. Refer to  DISASSEMBLY [10/2018 - ] 

    Result: 

    NG 

    REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY. Refer to  DISASSEMBLY [10/2018 - 10/2020]  , or refer to  DISASSEMBLY [10/2020 - ] 

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