AIR CONDITIONING SYSTEM, Diagnostic DTC:B1447/47

DTC Code DTC Name
B1447/47 Rear Air Mix Damper Control Servo Motor Circuit

DESCRIPTION

The No. 3 air conditioning radiator damper servo sub-assembly (rear air mix) 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 No. 3 air conditioning radiator damper servo sub-assembly (rear 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 rear 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.

Tech Tips

Confirm that there are no mechanical problems because this DTC can be output when either a damper link or the damper is mechanically locked.

DTC No. DTC Detection Condition Trouble Area
B1447/47 Rear air mix damper position does not change even if air conditioning amplifier assembly operates No. 3 air conditioning radiator damper servo sub-assembly (rear air mix)

  • No. 3 air conditioning radiator damper servo sub-assembly (rear air mix)

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

WIRING DIAGRAM

A01VZS3E09

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. Operate the rear side temperature adjustment switch.

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

    6. Read the Data List according to the display on the GTS.

      Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Air Mix Servo Actual Pulse(R) No. 3 air conditioning radiator damper servo sub-assembly (rear air mix) actual pulse / Min.: 0, Max.: 255

      MAX COLD: 113 (pulse)

      MAX HOT: 29 (pulse)

      		 -
      OK
      The display is as specified in the Normal Condition column.
      Result
      Result Proceed to
      NG A
      OK (When troubleshooting according to Problem Symptoms Table) B
      OK (When troubleshooting according to the DTC) C

    B

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

    C

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    A

  2. PERFORM ACTIVE TEST 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 / Active Test.

    5. Perform the Active Test according to the display on the GTS.

      Air Conditioner
      Tester Display Test Part Control Range Diagnostic Note
      Rear Air Mix Servo Targ Pulse No. 3 air conditioning radiator damper servo sub-assembly (rear air mix) pulse Min.: 0, Max.: 255 Operates between 29 and 113 pulses
      OK
      Air temperature changes in accordance with each control range.

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

  3. REPLACE NO. 3 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (REAR AIR MIX)


    1. Replace the No. 3 air conditioning radiator damper servo sub-assembly (rear air mix) 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.

    2. Check for DTCs.

      Result
      Result Proceed to
      DTC B1447/47 is output A
      DTC B1447/47 is not output B

    B

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

    A

  4. 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.

      Result
      Result Proceed to
      DTC B1447/47 is output A
      DTC B1447/47 is not output B

    A

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    B

    END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)