AIR CONDITIONING SYSTEM, Diagnostic DTC:B1446/46

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

DESCRIPTION

The No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal, reverse) based on the signals to move the No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) 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 driver seat side is controlled.

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 Note
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 No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix)

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

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

 Memorized (30 seconds or more) -

Tech Tips

The air conditioning amplifier assembly stores the DTC of the respective malfunction if it has occurred for the period of time indicated in the parentheses.

WIRING DIAGRAM

B006KKAE14

CAUTION / NOTICE / HINT

Note

When the battery is disconnected or the air conditioning amplifier assembly is replaced, be sure to perform servo motor initialization.

Click here

Tech Tips

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

PROCEDURE


  1. READ VALUE USING GTS (AIR MIX SERVO TARG PULSE[D], AIR MIX SERVO ACTUAL PULSE[D])


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    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) No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) target pulse

      Min.: 128

      Max.: 383

        for LHD:

      • MAX. COLD: 257 (pulse)

      • MAX. HOT: 165 (pulse)


        for RHD:

      • MAX. COLD: 255 (pulse)

      • MAX. HOT: 347 (pulse)

      • Displayed between 165 and 257 pulse (for LHD)

      • Displayed between 255 and 347 pulse (for RHD)

      • No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) system malfunction
      Air Mix Servo Actual Pulse(D) No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) actual pulse

      Min.: 128

      Max.: 383

        for LHD:

      • MAX. COLD: 257 (pulse)

      • MAX. HOT: 165 (pulse)


        for RHD:

      • MAX. COLD: 255 (pulse)

      • MAX. HOT: 347 (pulse)

      • Displayed between 165 and 257 pulse (for LHD)

      • Displayed between 255 and 347 pulse (for RHD)

      • No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) system malfunction

      Body Electrical > Air Conditioner > Data List
      Tester Display
      Air Mix Servo Targ Pulse(D)
      Air Mix Servo Actual Pulse(D)
      OK
      When the driver side temperature adjustment switch is turned from MAX COLD to MAX HOT, 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 for LHD: Click here for RHD: Click here

    C

    CHECK FOR DTC Click here

    D

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

    A

  2. CHECK NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (DRIVER SIDE AIR MIX)


    1. Replace the No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix).


      Tech Tips

      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. Clear the DTC.

      Click here


      Body Electrical > Air Conditioner > Clear DTCs

    3. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      OK
      DTC B1446/46 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY IS DEFECTIVE)

    NG

  3. CHECK AIR CONDITIONING HARNESS ASSEMBLY


    1. Replace the air conditioning harness assembly.


      Tech Tips

      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. Clear the DTC.

      Click here


      Body Electrical > Air Conditioner > Clear DTCs

    3. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      OK
      DTC B1446/46 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (AIR CONDITIONING HARNESS ASSEMBLY IS DEFECTIVE)

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY for LHD: Click here for RHD: Click here

  4. CHECK FOR DTC


    1. Clear the DTC.

      Click here


      Body Electrical > Air Conditioner > Clear DTCs

    2. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      OK
      DTC B1446/46 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY for LHD: Click here for RHD: Click here