AIR CONDITIONING SYSTEM, Diagnostic DTC:B1449/49

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

DESCRIPTION

The rear No. 2 cooling unit damper servo sub-assembly (rear mode damper servo) 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.

Tip:

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

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

Note

B1449/49

Rear Air Outlet Damper Control Servo Motor Circuit

Rear air outlet damper position does not change when the air conditioning amplifier assembly operates the rear No. 2 cooling unit damper servo sub-assembly (rear mode damper servo).

  • Rear No. 2 cooling unit damper servo sub-assembly (rear mode damper servo)

  • No. 2 air conditioning harness assembly

  • Harness or connector

  • Air conditioning amplifier assembly

Stored

(30 seconds or more)

-

WIRING DIAGRAM

E205490E02

PROCEDURE

  1. CHECK FOR DTC

    1. Clear the DTCs

      Click here

      Body Electrical > Air Conditioner > Clear DTCs

    2. Check for DTCs

      Click here

      Body Electrical > Air Conditioner > Trouble Codes

    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 DTC 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 No. 2 cooling unit damper servo sub-assembly (rear mode damper servo) is functioning properly

      Click here

      OK

      The display is as specified in the normal condition column.

      Body Electrical > Air Conditioner > Data List

      Tester Display

      Measurement Item

      Range

      Normal Condition

      Diagnostic Note

      Air Outlet Servo Pulse (R)

      Rear No. 2 cooling unit damper servo sub-assembly (rear mode damper servo) target pulse

      Min.: 0, Max.: 255

      83 (pulse): FACE

      41 (pulse): B/L

      7 (pulse): FOOT

      -

      Air Mix Servo Actual Pulse(R)

      Rear No. 2 cooling unit damper servo sub-assembly (rear mode damper servo) actual pulse

      Min.: 0, Max.: 255

      83 (pulse): FACE

      41 (pulse): B/L

      7 (pulse): FOOT

      -

    Result

    Result

    Proceed to

    OK (When troubleshooting according to problem symptoms table)

    A

    OK (When troubleshooting according to the DTC)

    B

    NG

    C
    A

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    Click here

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    Click here

    C

  3. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (REAR MODE DAMPER SERVO)

    1. Select the Active Test, use the intelligent tester to generate a control command, and then check that the rear No. 2 cooling unit damper servo sub-assembly (rear mode damper servo) operates

      Click here

      Body Electrical > Air Conditioner > Active Test

      Tester Display

      Measurement Item

      Control Range

      Diagnostic Note

      A/O Servo Pulse(Rr D)

      Rear No. 2 cooling unit damper servo sub-assembly (rear mode damper servo) pulse

      Min.: 0, Max.: 255

      -

      OK

      Rear No. 2 cooling unit damper servo sub-assembly (rear mode damper servo) operates normally.

    Result

    Result

    OK

    NG
    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    Click here

    NG

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

    1. Disconnect the Q13 harness connector.

    2. Disconnect the G12 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) - G12-1 (RBUS)

      Always

      Below 1 Ω

      Q13-4 (RBBU) - G12-23 (RBBU)

      Always

      Below 1 Ω

      Q13-2 (RBUG) - G12-21 (RBUG)

      Always

      Below 1 Ω

      G12-1 (RBUS) - Body ground

      Always

      10 kΩ or higher

      G12-23 (RBBU) - Body ground

      Always

      10 kΩ or higher

      G12-21 (RBUG) - Body ground

      Always

      10 kΩ or higher

    Result

    Result

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE REAR NO. 2 COOLING UNIT DAMPER SERVO SUB-ASSEMBLY (REAR MODE DAMPER SERVO)

    1. Replace the rear No. 2 cooling unit damper servo sub-assembly (rear mode damper servo)

      Click here

      Tip:

      Since the rear No. 2 cooling unit damper servo sub-assembly (rear mode damper servo) cannot be inspected while it is removed from the vehicle, replace the rear No. 2 cooling unit damper servo sub-assembly (rear mode damper servo) with a new or normally functioning one.

    Result

    Result

    NEXT
    NEXT

  6. CHECK FOR DTC

    1. Clear the DTCs

      Click here

      Body Electrical > Air Conditioner > Clear DTCs

    2. Check for DTCs

      Click here

      Body Electrical > Air Conditioner > Trouble Codes

      OK

      DTC B1449 is not output.

    Result

    Result

    OK

    NG
    OK

    END (REAR NO. 2 COOLING UNIT DAMPER SERVO SUB-ASSEMBLY [REAR MODE DAMPER SERVO] IS FAULTY)

    NG

  7. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    1. Replace the air conditioning amplifier assembly with a new or normally functioning one

      Click here

    Result

    Result

    NEXT
    NEXT

  8. CHECK FOR DTC

    1. Clear the DTCs

      Click here

      Body Electrical > Air Conditioner > Clear DTCs

    2. Check for DTCs

      Click here

      Body Electrical > Air Conditioner > Trouble Codes

      OK

      DTC B1449 is not output.

    Result

    Result

    OK

    NG
    OK

    END (AIR CONDITIONING AMPLIFIER ASSEMBLY IS FAULTY)

    NG

    REPLACE NO. 2 AIR CONDITIONING HARNESS ASSEMBLY

    Click here