AIR CONDITIONING SYSTEM(for Manual 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 damper servo motor 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 servo motor to any position. As a result, the amount of air that has passed through the evaporator and is passing through the heater core is adjusted, and the temperature of the air blowing toward the driver side is controlled.

Tech Tips

Confirm that no mechanical problem is present because this trouble code can be output 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 damper servo motor.

  • Air mix damper servo motor

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

WIRING DIAGRAM

B001WOVE66

PROCEDURE


  1. READ VALUE USING GTS (AIR MIX SERVO TARG PULSE[D], AIR MIX SERVO ACTUAL PULSE[D])


    1. Use the Data List to check if the air mix damper servo motor is functioning properly Click here.

      Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Air Mix Servo Targ Pulse(D) Air mix damper servo motor target pulse / Min.: 128, Max.:383

        for LHD:

      • MAX COLD: 254 (pulse)

      • MAX HOT: 299 (pulse)


        for RHD:

      • MAX COLD: 258 (pulse)

      • MAX HOT: 213 (pulse)

      • Displayed between 254 and 299 pulse (for LHD)

      • Displayed between 213 and 258 pulse (for RHD)

      • Air mix damper servo motor system malfunction
      Air Mix Servo Actual Pulse(D)) Air mix damper servo motor actual pulse / Min.: 128, Max.:383

        for LHD:

      • MAX COLD: 254 (pulse)

      • MAX HOT: 299 (pulse)


        for RHD:

      • MAX COLD: 258 (pulse)

      • MAX HOT: 213 (pulse)

      • Displayed between 254 and 299 pulse (for LHD)

      • Displayed between 213 and 258 pulse (for RHD)

      • Air mix damper servo motor system malfunction
      OK
      When the temperature adjustment switch is turned MAX COLD to MAX HOT, the actual pulse changes following the target pulse.
      Result
      Result Proceed to
      Target pulse changes but actual pulse does not change A
      Target pulse and actual pulse do not change B
      Actual pulse changes following the target pulse (When troubleshooting according to the DTC) C
      Actual pulse changes following the target pulse (When troubleshooting according to Problem Symptoms Table) D

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    C

    CHECK FOR DTC Click here

    E

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

    A

  2. CHECK AIR MIX DAMPER SERVO MOTOR


    1. Replace the air mix damper servo motor.



      1. R LH ().

      Tech Tips

      Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a normal one.

    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC B1446/46 is not output.

    OK

    END (AIR MIX DAMPER SERVO MOTOR WAS DEFECTIVE)

    NG

  3. CHECK AIR CONDITIONING HARNESS ASSEMBLY


    1. Replace the air conditioning harness assembly with a new or known good one.


    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC B1446/46 is not output.

    OK

    END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  4. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1446/46 is not output.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here