AIR CONDITIONING SYSTEM, Diagnostic DTC:B1442/42

DTC Code DTC Name
B1442/42 Air Inlet Damper Control Servo Motor Circuit

DESCRIPTION

The No. 1 blower damper servo sub-assembly (fresh/recirculation damper) 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 these signals to move the air inlet mode selection No. 1 blower damper servo sub-assembly (fresh/recirculation damper) to the appropriate position, which controls the air inlet mode (fresh, recirculation/fresh, and recirculation).

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
B1442/42 Air Inlet Damper Control Servo Motor Circuit Air inlet damper position sensor value does not change even if air conditioning amplifier assembly operates No. 1 blower damper servo sub-assembly (fresh/recirculation damper)

  • No. 1 blower damper servo sub-assembly (fresh/recirculation damper)

  • 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 brackets.

WIRING DIAGRAM

A01MHVGE01

CAUTION / NOTICE / HINT

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


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Operate the recirculation/fresh switch.

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

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


      Body Electrical > Air Conditioner > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Air Inlet Damper Targ Pulse No. 1 blower damper servo sub-assembly (fresh/recirculation damper) target pulse

      Min.: 128

      Max.: 383

      for LHD:

      RECIRCULATION: 147 (pulse)

      FRESH: 135 (pulse)

      for RHD:

      RECIRCULATION: 135 (pulse)

      FRESH: 153 (pulse)

      		 -
      Air Inlet Damper Actual Pulse No. 1 blower damper servo sub-assembly (fresh/recirculation damper) actual pulse

      Min.: 128

      Max.: 383

      for LHD:

      RECIRCULATION: 147 (pulse)

      FRESH: 135 (pulse)

      for RHD:

      RECIRCULATION: 135 (pulse)

      FRESH: 153 (pulse)

      		 -

      Body Electrical > Air Conditioner > Data List
      Tester Display
      Air Inlet Damper Targ Pulse
      Air Inlet Damper Actual Pulse
      OK
      When the recirculation/fresh switch is turned to recirculation mode or fresh mode, 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 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 BLOWER DAMPER SERVO SUB-ASSEMBLY (FRESH/RECIRCULATION DAMPER)


    1. Replace the No. 1 blower damper servo sub-assembly (fresh/recirculation damper).

      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. Clear the DTC.

      Click here


      Body Electrical > Air Conditioner > Clear DTCs

    3. Check for DTC.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1442/42 is not output A
      DTC B1442/42 is output B

    A

    END (NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY (FRESH/RECIRCULATION DAMPER) WAS DEFECTIVE)

    B

  3. CHECK 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. Clear the DTC.

      Click here


      Body Electrical > Air Conditioner > Clear DTCs

    3. Check for DTC.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1442/42 is not output A
      DTC B1442/42 is output B

    A

    END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  4. CHECK FOR DTC


    1. Clear the DTC.

      Click here


      Body Electrical > Air Conditioner > Clear DTCs

    2. Check for DTC.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1442/42 is not output A
      DTC B1442/42 is output B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here