AIR CONDITIONING SYSTEM (for Manual Air Conditioning System), Diagnostic DTC:B1447

DTC Code DTC Name
B1447 Air Mix Damper Control Servo Motor Circuit (Rear)

DESCRIPTION

The rear air mix damper servo sub-assembly sends pulse signals to indicate the damper position to the air conditioning amplifier. The air conditioning amplifier activates the motor (normal or reverse) based on these signals to move the rear air mix damper to any position. As a result, the amount of air passing through the heater core after passing through the evaporator is adjusted and the temperature of the air blowing toward the rear is controlled.

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

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
B1447 Rear air mix damper position does not change when the air conditioning amplifier operates the rear air mix damper servo sub-assembly.

  • Rear air mix damper servo sub-assembly

  • No. 2 air conditioning harness assembly

  • Harness or connector

  • Air conditioning amplifier

WIRING DIAGRAM

A0096PUE06

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (REAR AIR MIX DAMPER SERVO)


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

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

      9 (pulse): MAX COOL

      54 (pulse): MAX HOT

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

      9 (pulse): MAX COOL

      54 (pulse): MAX HOT

      		 -
      OK
      The display is as specified in the normal condition column.
      Result
      Result Proceed to
      OK (When troubleshooting according to problem symptoms table) A
      OK (When troubleshooting according to the DTC) B
      NG C

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    C

    PERFORM ACTIVE TEST USING INTELLIGENT TESTER (REAR AIR MIX DAMPER SERVO) Click here

    A

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

  2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (REAR AIR MIX DAMPER SERVO)


    1. Select the Active Test, use the intelligent tester to generate a control command, and then check that the rear air mix damper servo sub-assembly operates Click here.

      Air Conditioner
      Tester Display Test Part Control Range Diagnostic Note
      Rear Air Mix Servo Targ Pulse Rear air mix damper servo sub-assembly target pulse Min.: 0, Max.: 255 -
      OK
      Rear air mix damper servo sub-assembly operates normally.

    NG

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

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  3. 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

  4. REPLACE REAR AIR MIX DAMPER SERVO SUB-ASSEMBLY


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

      Tech Tips

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


    NEXT

  5. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1447 is not output.

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

    END (REAR AIR MIX DAMPER SERVO SUB-ASSEMBLY IS FAULTY)

  6. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY


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


    NEXT

  7. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1447 is not output.

    NG

    REPLACE NO. 2 AIR CONDITIONING HARNESS ASSEMBLY Click here

    OK

    END (AIR CONDITIONING AMPLIFIER ASSEMBLY IS FAULTY)