AIR CONDITIONING SYSTEM(for Automatic Air Conditioning System), Diagnostic DTC:B1446/46

DTC Code DTC Name
B1446/46 Air Mix Damper Control Servo Motor Circuit (Driver Side)

DESCRIPTION

The air mix damper servo sub-assembly (for driver side) 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 air mix damper servo sub-assembly (for driver side) to the appropriate position. This adjusts the amount of air passing through the heater core after passing the evaporator and controls the temperature of the output air. The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.

The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

B1446/46

Air Mix Damper Control Servo Motor Circuit (Driver Side)

Air mix damper position sensor value does not change even if air conditioning amplifier assembly operates air mix damper servo sub-assembly (for driver side)

  • Air mix damper servo sub-assembly (for driver side)

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

Memorized

(30 sec. or more)*1

  • *1: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.

WIRING DIAGRAM

E265642E08

CAUTION / NOTICE / HINT

Tip:

Confirm that no mechanical problem is present because this DTC can be output when either a damper link or damper is mechanically locked.

PROCEDURE

  1. READ VALUE USING GTS

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Operate the driver side temperature adjustment switch.

    5. Enter the following menus: Body Electrical / Air Conditioner / Data List.

    6. Check the value(s) by referring to the table below.

      Body Electrical > Air Conditioner > Data List

      Tester Display

      Measurement Item

      Range

      Normal Condition

      Diagnostic Note

      Air Mix Servo Targ Pulse(D)

      Air mix damper servo sub-assembly (for driver side) target pulse

      Min.: 0

      Max.: 255

      • for LHD:

      • MAX. COLD: 92 (pulse)

      • MAX. HOT: 5 (pulse)

      • for RHD:

      • MAX. COLD: 6 (pulse)

      • MAX. HOT: 93 (pulse)

      -

      Body Electrical > Air Conditioner > Data List

      Tester Display

      Air Mix Servo Targ Pulse(D)

      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

    NG

    C
    B

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    Click hereClick hereClick hereClick hereClick hereClick here

    C

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    Click hereClick hereClick hereClick here

    A

  2. REPLACE AIR MIX DAMPER SERVO SUB-ASSEMBLY (FOR DRIVER SIDE)

    1. Replace the air mix damper servo sub-assembly (for driver side).

      Click hereClick hereClick hereClick here

      Tip:

      Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or known good one and check that the condition returns to normal.

    2. Check for the DTC.

      Body Electrical > Air Conditioner > Trouble Codes

      Result

      Result

      Proceed to

      DTC B1446/46 is output

      A

      DTC B1446/46 is not output

      B
    B

    END (AIR MIX DAMPER SERVO SUB-ASSEMBLY (FOR DRIVER SIDE) WAS DEFECTIVE)

    A

  3. REPLACE AIR CONDITIONING HARNESS ASSEMBLY

    1. Replace the air conditioning harness assembly.

      Click hereClick hereClick hereClick hereClick hereClick here

      Tip:

      Since the air conditioning harness assembly cannot be inspected while it is removed from the vehicle, replace the air conditioning harness assembly with a new or known good one and check that the condition returns to normal.

    2. Check for the DTC.

      Body Electrical > Air Conditioner > Trouble Codes

      Result

      Result

      Proceed to

      DTC B1446/46 is output

      A

      DTC B1446/46 is not output

      B
    A

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    Click hereClick hereClick hereClick here

    B

    END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)