AIR CONDITIONING SYSTEM(for Automatic Air Conditioning System), Diagnostic DTC:B1449/49

DTC Code DTC Name
B1449/49 Rear Air Outlet Damper Control Servo Motor Circuit

DESCRIPTION

The rear 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 rear air outlet damper to any position, which controls the air outlet modes.

The air conditioning amplifier assembly communicates with the servo through the No. 2 air conditioning harness.

Tech Tips

Confirm that there are no mechanical problems because this DTC may be stored when either a damper link or damper is mechanically locked.

DTC Code DTC Detection Condition Trouble Area
B1449/49 Rear air outlet damper position does not change when the air conditioning amplifier assembly operates the rear mode damper servo sub-assembly.

  • Rear mode damper servo sub-assembly

  • No. 2 air conditioning harness assembly

  • Harness or connector

  • Air conditioning amplifier assembly

WIRING DIAGRAM

B001DSAE07
*a Rear Mode Damper Servo Sub-assembly
*b Air Conditioning Amplifier Assembly
*c No. 2 Air Conditioning Harness Assembly

PROCEDURE


  1. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC B1449/49 is not output A
      DTC B1449/49 is output B
      DTC B1449/49 and B1497/97 are output C

    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    GO TO B1497/97 Click here

    B

  2. READ VALUE USING INTELLIGENT TESTER (REAR MODE DAMPER SERVO)


    1. Use the Data List to check if the rear mode damper servo sub-assembly is functioning properly Click here.

      Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Air Outlet Servo Pulse (R) Rear mode damper servo sub-assembly target pulse / Min.: 0, Max.: 255

      83 (pulse): FACE

      41 (pulse): B/L

      7 (pulse): FOOT

      		 -
      Air Mix Servo Actual Pulse (R) Rear mode damper servo sub-assembly actual pulse / Min.: 0, Max.: 255

      83 (pulse): FACE

      41 (pulse): B/L

      7 (pulse): FOOT

      		 -
      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
      Both target pulse and actual pulse do not display C
      Target pulse displays normally, but actual pulse does not display D

    B

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

    C

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    D

    CHECK HARNESS AND CONNECTOR (NO. 2 AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER) Click here

    A

  3. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1449 is not output.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  4. CHECK HARNESS AND CONNECTOR (NO. 2 AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER)


    1. Disconnect the Q13 harness connector.

    2. Disconnect the G24 amplifier connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q13-3 (RBUS) - G24-1 (RBUS) Always Below 1 Ω
      Q13-4 (RBBU) - G24-23 (RBBU) Always Below 1 Ω
      Q13-2 (RBUG) - G24-21 (RBUG) Always Below 1 Ω
      G24-1 (RBUS) - Body ground Always 10 kΩ or higher
      G24-23 (RBBU) - Body ground Always 10 kΩ or higher
      G24-21 (RBUG) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK REAR MODE DAMPER SERVO SUB-ASSEMBLY


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

      Tech Tips

      Since the rear mode damper servo sub-assembly cannot be inspected while it is removed from the vehicle, replace the rear mode damper servo sub-assembly with a new or normally functioning one.

    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC B1449 is not output.

    OK

    END (REAR MODE DAMPER SERVO SUB-ASSEMBLY IS FAULTY)

    NG

  6. CHECK AIR CONDITIONING HARNESS ASSEMBLY


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

    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC B1449 is not output.

    OK

    END (AIR CONDITIONING HARNESS ASSEMBLY IS FAULTY)

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here