AIR CONDITIONING SYSTEM, Diagnostic DTC:B1443/43

DTC Code DTC Name
B1443/43 Air Outlet Damper Control Servo Motor Circuit

DESCRIPTION

The mode damper servo sub-assembly sends pulse signals to indicate the damper position to the air conditioning amplifier assembly. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the mode damper servo sub-assembly to any position, which controls the air outlet switching.

The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.

Tech Tips

Confirm that no mechanical problem is present because this DTC can be stored when either a damper link or the damper is mechanically locked.

DTC No. DTC Detection Condition Trouble Area
B1443/43 Air outlet damper position sensor value does not change even though the air conditioning amplifier assembly operates the mode damper servo sub-assembly

  • Mode damper servo sub-assembly

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

WIRING DIAGRAM

A0042D7E03

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Operate the MODE switch.

    5. Enter the following menus: Body Electrical / Air Conditioner / Data List.

    6. Check the value(s) by referring to the table below.

      Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Air Outlet Servo Actu Pulse(D)

      Mode damper servo sub-assembly actual pulse /

      Min.: 0, Max.: 255

      FACE: 47 (pulse)

      B/L: 37 (pulse)

      FOOT: 17 (pulse)

      FOOT/DEF: 9 (pulse)

      DEF: 5 (pulse)

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

    B

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

    C

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    A

  2. PERFORM ACTIVE TEST USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Air Conditioner / Active Test.

    5. Check the operation by referring to the table below.

      Air Conditioner
      Tester Display Test Part Control Rage Diagnostic Note
      Air Outlet Servo Pulse (D) Mode damper servo sub-assembly pulse Min.: 0, Max.: 255 Operates between 5 and 47 pulses
      OK
      Air flow position changes in accordance with each control range.

    NG

    REPLACE MODE DAMPER SERVO SUB-ASSEMBLY Click here

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  3. REPLACE MODE DAMPER SERVO SUB-ASSEMBLY


    1. Replace the mode damper servo sub-assembly Click here.

      Tech Tips

      Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or known good one and check that the condition returns to normal.

    2. Check for the DTC.

      Result
      Result Proceed to
      DTC B1443/43 is output A
      DTC B1443/43 is not output B

    B

    END (MODE DAMPER SERVO SUB-ASSEMBLY WAS DEFECTIVE)

    A

  4. REPLACE AIR CONDITIONING HARNESS ASSEMBLY


    1. Replace the air conditioning harness assembly Click here.

      Tech Tips

      Since the air conditioning harness assembly cannot be inspected while it is removed from the vehicle, replace the air conditioning harness assembly with a new or known good one and check that the condition returns to normal.

    2. Check for the DTC.

      Result
      Result Proceed to
      DTC B1443/43 is output A
      DTC B1443/43 is not output B

    B

    END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)

    A

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here