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 air mix control servo motor (for driver side) 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 can 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 even if the air conditioning amplifier assembly operates the air mix control servo motor (for driver side).

  • Air mix control servo motor (for driver side)

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

WIRING DIAGRAM

A01IOATE22

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC B1446/46 is not output A
      DTC B1446/46 is output B
      DTC B1446/46 and B1497/97 are output C

    B

    READ VALUE USING INTELLIGENT TESTER Click here

    C

    GO TO DTC B1497/97 Click here

    A

    USE SIMULATION METHOD TO CHECK Click here

  2. READ VALUE USING INTELLIGENT TESTER


    1. Use the Data List to check if the servo motor is functioning properly.

      Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Air Mix Servo Targ Pulse (D) Air mix control servo motor (for driver side) target pulse / Min.: 0, Max.: 255

      for LHD:


      • 92 (pulse): MAX COOL

      • 5 (pulse): MAX HOT

      for RHD:


      • 6 (pulse): MAX COOL

      • 93 (pulse): MAX HOT

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

    B

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

    C

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    A

  3. CHECK AIR MIX CONTROL SERVO MOTOR (FOR DRIVER SIDE)


    1. Replace the air mix control servo motor (for driver side) Click here.

      Tech Tips

      Since the air mix control servo motor cannot be inspected while it is removed from the vehicle, replace the air mix control servo motor with a new or normally functioning one.

    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC B1446 is not output.

    B

    CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    A

    END (AIR MIX CONTROL SERVO MOTOR [FOR DRIVER SIDE] IS FAULTY)

  4. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


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

    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC B1446 is not output.

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    A

    END (AIR CONDITIONING HARNESS ASSEMBLY IS FAULTY)