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AIR CONDITIONING SYSTEM (for Manual Air Conditioning System), Diagnostic DTC:B1446

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DTC Code DTC Name
B1446 Air Mix Damper Control Servo Motor Circuit (Driver Side)
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DESCRIPTION

The No. 1 air conditioning radiator damper servo sub-assembly (air mix damper servo) 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 air mix damper to any position. As a result, the air mix damper varies the mixture of hot air from the heater core and cold air from the evaporator so that the temperature of the air is as requested.

Tip:

Confirm that no mechanical problem is present because this trouble code may be stored when either a damper link or damper is mechanically locked.

DTC Code DTC Detection Condition Trouble Area
B1446 The air mix damper position does not change for 30 seconds or more when the air conditioning amplifier assembly operates the No. 1 air conditioning radiator damper servo sub-assembly (air mix damper servo).

  • No. 1 air conditioning radiator damper servo sub-assembly (air mix damper servo)

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly
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WIRING DIAGRAM

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INSPECTION PROCEDURE

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PROCEDURE


  1. Click here

    READ VALUE USING INTELLIGENT TESTER (AIR MIX SERVO TARG PULSE [D])


    1. Use the Data List to check if the No. 1 air conditioning radiator damper servo sub-assembly (air mix damper servo) is functioning properly (Click here).

      Table 1. Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Air Mix Servo Targ Pulse (D) No. 1 air conditioning radiator damper servo sub-assembly (air mix damper servo) target pulse / Min.: 0, Max.: 255
      • for LHD

      • MAX. COOL: 90 (pulse)

      • MAX. HOT: 8 (pulse)


      • for RHD

      • MAX. COOL: 8 (pulse)

      • MAX. HOT: 90 (pulse)

      		 -
      OK
      The display is as specified in the normal condition column.
      Table 2. Result
      Result Proceed to
      OK (When troubleshooting according to the DTC) A
      OK (When troubleshooting according to problem symptoms table) B
      NG C

  2. Click here

    REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (AIR MIX DAMPER SERVO)


    1. Temporarily replace the No. 1 air conditioning radiator damper servo sub-assembly (air mix damper servo).


      Tip:

      Since the No. 1 air conditioning radiator damper servo sub-assembly (air mix damper servo) cannot be inspected while it is removed from the vehicle, replace the No. 1 air conditioning radiator damper servo sub-assembly (air mix damper servo) with a new or normally functioning one.

    2. Clear the DTCs (Click here).

    3. Check for DTCs (Click here).

      Table 3. Result
      Result Proceed to
      DTC B1446 is not output A
      DTC B1446 is output B

  3. Click here

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY


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


    2. Clear the DTCs (Click here).

    3. Check for DTCs (Click here).

      Table 4. Result
      Result Proceed to
      DTC B1446 is not output A
      DTC B1446 is output B

  4. Click here

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLYClick here

  5. Click here

    END (NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY [AIR MIX DAMPER SERVO] IS FAULTY)

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    END (AIR CONDITIONING HARNESS ASSEMBLY IS FAULTY)

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    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLEClick here