AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System), Diagnostic DTC:B1446/46

DTC Code DTC Name
B1446/46 Air Mix Damper Control Servo Motor Circuit (Driver Side)

DESCRIPTION

The damper servo sub-assembly (driver side air mix damper servo) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the air mix damper (for driver side) to any position. As a result, the air mix damper (for driver side) varies the mixture of hot air from the heater core and cold air from the evaporator so that the temperature of the air blowing toward the front passenger side is as requested.

Tech Tips

Confirm that no mechanical problem is present because this trouble code may be stored when either a damper link or damper is mechanically locked.

DTC Code DTC Detection Condition Trouble Area
B1446/46 The air mix damper position does not change when the air conditioning amplifier assembly operates the damper servo sub-assembly (driver side air mix damper servo).

  • Damper servo sub-assembly (driver side air mix damper servo)

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

WIRING DIAGRAM

A009BDJE53

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (DRIVER SIDE AIR MIX DAMPER SERVO)


    1. Use the Data List to check if the damper servo sub-assembly (driver side air mix damper servo) is functioning properly Click here.

      Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Air Mix Servo Targ Pulse (D) Damper servo sub-assembly (driver side air mix damper servo) target pulse / Min.: 0, Max.: 255

      for LHD:


      • 107 (pulse): MAX COOL

      • 26 (pulse): MAX HOT

      for RHD:


      • 112 or 127 (pulse): MAX COOL

      • 21 or 31 (pulse): MAX HOT

      		 -
      Air Mix Servo Actual Pulse (D) Damper servo sub-assembly (driver side air mix damper servo) actual pulse / Min.: 0, Max.: 255

      for LHD:


      • 107 (pulse): MAX COOL

      • 26 (pulse): MAX HOT

      for RHD:


      • 112 or 127 (pulse): MAX COOL

      • 21 or 31 (pulse): MAX HOT

      		 -
      OK
      The display is as specified in the normal condition column.
      Result
      Result Proceed to
      OK (When troubleshooting according to problem symptoms table) A
      OK (When troubleshooting according to the DTC) B
      NG C

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    C

    PERFORM ACTIVE TEST USING INTELLIGENT TESTER (DRIVER SIDE AIR MIX DAMPER SERVO) Click here

    A

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

  2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (DRIVER SIDE AIR MIX DAMPER SERVO)


    1. Select the Active Test, use the intelligent tester to generate a control command, and then check that the damper servo sub-assembly (driver side air mix damper servo) operates Click here.

      Air Conditioner
      Tester Display Test Part Control Range Diagnostic Note
      Air Mix Servo Targ Pulse (D) Damper servo sub-assembly (driver side air mix damper servo) target pulse Min.: 0, Max.: 255 -
      OK
      Damper servo sub-assembly (driver side air mix damper servo) operates normally.

    NG

    REPLACE DAMPER SERVO SUB-ASSEMBLY (DRIVER SIDE AIR MIX DAMPER SERVO) Click here

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  3. REPLACE DAMPER SERVO SUB-ASSEMBLY (DRIVER SIDE AIR MIX DAMPER SERVO)


    1. Replace the damper servo sub-assembly (driver side air mix damper servo) Click here.

      Tech Tips

      Since the damper servo sub-assembly (driver side air mix damper servo) cannot be inspected while it is removed from the vehicle, replace the damper servo sub-assembly (driver side air mix damper servo) with a new or normally functioning one.


    NEXT

  4. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1446 is not output.

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

    END (DAMPER SERVO SUB-ASSEMBLY [DRIVER SIDE AIR MIX DAMPER SERVO] IS FAULTY)

  5. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. Temporarily replace the air conditioning amplifier assembly with a new or normally functioning one Click here.


    NEXT

  6. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1446 is not output.

    NG

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY Click here

    OK

    END (AIR CONDITIONING AMPLIFIER ASSEMBLY IS FAULTY)