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 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 rear mode damper servo motor to the appropriate position, which controls the air outlet modes.

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
B1449/49 The rear mode damper servo motor position does not change even if the air conditioning amplifier assembly operates the rear air outlet damper servo motor.

  • Rear mode damper servo motor

  • No. 2 air conditioning harness assembly

  • Harness or connector

  • Air conditioning amplifier assembly

WIRING DIAGRAM

B001YN8E16
*a Rear Mode Damper Servo Motor
*b No. 2 Air Conditioning Harness Assembly
*c Air Conditioning Amplifier Assembly
*d LIN Communication Line

PROCEDURE


  1. READ VALUE USING GTS (AIR OUTLET SERVO [R], AIR OUTLET SERVO ACTUAL PLS[R])


    1. Use the Data List to check if the rear mode damper servo motor 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 motor target pulse / Min.: 128, Max.: 383

      • FACE1: 258 (pulse)

      • FACE2: 258 (pulse)

      • B/L1: 277 (pulse)

      • FOOT-O: 290 (pulse)

      • FOOT-D: 290 (pulse)

      • FOOT-R: 290 (pulse)

      • FOOT-M: 307 (pulse)

      • F/D: 316 (pulse)

      • DEF: 328 (pulse)

      • Displayed between 258 and 328 pulse

      • Rear mode damper servo motor system malfunction
      Air Outlet Servo Actual Pls(R) Rear mode damper servo motor actual pulse / Min.: 128, Max.: 383

      • FACE1: 258 (pulse)

      • FACE2: 258 (pulse)

      • B/L1: 277 (pulse)

      • FOOT-O: 290 (pulse)

      • FOOT-D: 290 (pulse)

      • FOOT-R: 290 (pulse)

      • FOOT-M: 307 (pulse)

      • F/D: 316 (pulse)

      • DEF: 328 (pulse)

      • Displayed between 258 and 328 pulse

      • Rear mode damper servo motor system malfunction
      OK
      When the rear mode switch is turned, 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 HARNESS AND CONNECTOR (NO. 2 AIR CONDITIONING HARNESS ASSEMBLY - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Disconnect the K19 No. 2 air conditioning harness assembly connector.

    2. Disconnect the E36 air conditioning amplifier assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K19-2 (RBUG) - E36-12 (RBUG) Always Below 1 Ω
      K19-3 (RBUS) - E36-13 (RBUS) Always Below 1 Ω
      K19-4 (RBBU) - E36-14 (RBBU) Always Below 1 Ω
      K19-2 (RBUG) or E36-12 (RBUG) - Body ground Always 10 kΩ or higher
      K19-3 (RBUS) or E36-13 (RBUS) - Body ground Always 10 kΩ or higher
      K19-4 (RBBU) or E36-14 (RBBU) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK REAR MODE DAMPER SERVO MOTOR


    1. Replace the rear mode damper servo motor Click here.

      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 B1449/49 is not output.

    OK

    END (REAR MODE DAMPER SERVO MOTOR WAS DEFECTIVE)

    NG

  4. CHECK NO. 2 AIR CONDITIONING HARNESS ASSEMBLY


    1. Replace the No. 2 air conditioning harness assembly with a new or known good one Click here.

    2. Clear the DTCs Click here.

    3. Check for DTCs Click here.

      OK
      DTC B1449/49 is not output.

    OK

    END (NO. 2 AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  5. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1449/49 is not output.

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here