AIR CONDITIONING SYSTEM, Diagnostic DTC:B1441/41

DTC Code DTC Name
B1441/41 Air Mix Damper Control Servo Motor Circuit (Passenger Side)

DESCRIPTION

The air mix control servo motor sends pulse signals to indicate the damper position to the A/C amplifier. The A/C amplifier activates the motor (normal or reverse) based on these signals to move the air mix damper (front passenger side) 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 passenger side is controlled.

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

Tech Tips

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

DTC No. DTC Detection Condition Trouble Area
B1441/41 Air mix damper position sensor value does not change even if A/C amplifier operates air mix control servo motor

  • Air mix control servo motor

  • Air conditioning harness

  • A/C amplifier

WIRING DIAGRAM

A01NE4QE20

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the intelligent tester on.

    4. Operate the front passenger side temperature adjustment switch.

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

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

      Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Air Mix Servo Targ Pulse (P) Passenger side air mix servo motor target pulse / Min.: 0, Max.: 255

      for LHD:

      MAX. COLD: 105 (pulse)

      MAX. HOT: 7 (pulse)

      for RHD:

      MAX. COLD: 5 (pulse)

      MAX. HOT: 103 (pulse)

      		 -
      Air Mix Servo Actual Pulse (P) Passenger side air mix servo motor actual pulse / Min.: 0, Max.: 255

      for LHD:

      MAX. COLD: 105 (pulse)

      MAX. HOT: 7 (pulse)

      for RHD:

      MAX. COLD: 5 (pulse)

      MAX. HOT: 103 (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 A/C AMPLIFIER Click here

    A

  2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the intelligent tester on.

    4. Enter the following menus: Body / Air Conditioner / Active Test.

    5. Check the operation by referring to the table below.

      Air Conditioner
      Tester Display Test Part Control Range Diagnostic Note
      Air Mix Servo Targ Pulse (P) Air mix servo motor pulse (P side) Min.: 0, Max.: 255 -
      OK
      Air temperature changes in accordance with each control range.

    NG

    INSPECT AIR MIX CONTROL SERVO MOTOR Click here

    OK

    REPLACE A/C AMPLIFIER Click here

  3. INSPECT AIR MIX CONTROL SERVO MOTOR


    1. Replace the air mix control servo motor 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 a known good one and check that the condition returns to normal.

    2. Check for the DTC.

      Result
      Result Proceed to
      DTC B1441/41 is output A
      DTC B1441/41 is not output B

    B

    END (AIR MIX CONTROL SERVO MOTOR WAS DEFECTIVE)

    A

  4. INSPECT AIR CONDITIONING HARNESS


    1. Replace the air conditioning harness Click here.

      Tech Tips

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

    2. Check for the DTC.

      Result
      Result Proceed to
      DTC B1441/41 is output A
      DTC B1441/41 is not output B

    B

    END (AIR CONDITIONING HARNESS WAS DEFECTIVE)

    A

    REPLACE A/C AMPLIFIER Click here