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. 4 air conditioning radiator damper servo sub-assembly*1 or No. 3 air conditioning radiator damper servo sub-assembly (driver side lower air mix)*2 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 No. 4 air conditioning radiator damper servo sub-assembly*1 or No. 3 air conditioning radiator damper servo sub-assembly (driver side lower air mix)*2 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 side lower 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
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. 4 air conditioning radiator damper servo sub-assembly*1 or No. 3 air conditioning radiator damper servo sub-assembly (driver side lower air mix)*2

  • No. 4 air conditioning radiator damper servo sub-assembly (driver side lower air mix)*1

  • No. 3 air conditioning radiator damper servo sub-assembly (driver side lower air mix)*2

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

Memorized

(30 seconds or more)

Tech Tips

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

WIRING DIAGRAM

B002CUIE04

CAUTION / NOTICE / HINT

Note

Before disconnecting the cable from the negative (-) battery terminal or replacing the air conditioning amplifier assembly, record the last operation state of the air conditioning for each transmitter. After replacement, it is necessary to perform memory registration for each transmitter.

Click here

Tech Tips

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 engine switch on (IG).

    3. Turn the GTS on.

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

    5. 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
      COOL A/M Servo Targ Pls(D) No. 4 air conditioning radiator damper servo sub-assembly target pulse*1 or No. 3 air conditioning radiator damper servo sub-assembly (driver side lower air mix) target pulse*2

      Min.: 128

      Max.: 383

      • MAX. COLD*3: 254 (pulse)

      • MAX. HOT*4: 360 (pulse)

      		 -
      COOL A/M Servo Actual Pulse(D) No. 4 air conditioning radiator damper servo sub-assembly actual pulse (driver side lower air mix) actual target pulse*1 or No. 3 air conditioning radiator damper servo sub-assembly (driver side lower air mix) actual target pulse*2

      Min.: 128

      Max.: 383

      • MAX. COLD*3: 254 (pulse)

      • MAX. HOT*4: 360 (pulse)

      		 -

      • *1: for LHD

      • *2: for RHD

      • *3: Set temperature: LO

      • *4: Set temperature: HI


      Body Electrical > Air Conditioner > Data List
      Tester Display
      COOL A/M Servo Targ Pls(D)
      COOL A/M Servo Actual Pulse(D)
      OK
      The display is as specified in the Normal Condition column.
      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 Click here

    C

    RECONFIRM DTC OUTPUT Click here

    D

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

    A

  2. REPLACE NO. 4 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY OR NO. 3 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY


    1. Replace the No. 4 air conditioning radiator damper servo sub-assembly*1 or No. 3 air conditioning radiator damper servo sub-assembly (driver side lower air mix)*2 with a new or normally functioning one.

      Click here

      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.


      • *1: for LHD

      • *2: for RHD

    2. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1446/46 is output A
      DTC B1446/46 is not output (for LHD) B
      DTC B1446/46 is not output (for RHD) C

    B

    END (NO. 4 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (DRIVER SIDE LOWER AIR MIX) WAS DEFECTIVE)

    C

    END (NO. 3 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (DRIVER SIDE LOWER AIR MIX) WAS DEFECTIVE)

    A

  3. REPLACE AIR CONDITIONING HARNESS ASSEMBLY


    1. Replace the air conditioning harness assembly.

      Click here

      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. Check for DTCs.

      Click here


      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 here

    B

    END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)

  4. RECONFIRM DTC OUTPUT


    1. Check for DTCs.

      Click here


      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 here

    B

    USE SIMULATION METHOD TO CHECK Click here