AIR CONDITIONING SYSTEM, Diagnostic DTC:B1442/42

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

DESCRIPTION

The damper servo (air inlet control) sends pulse signals to inform the A/C amplifier of the damper position. The A/C amplifier activates the motor (normal, reverse) based on the signals to move the air inlet mode selection air inlet control damper to any position, which controls the intake air settings (FRESH, FRESH/RECIRCULATION, and RECIRCULATION).

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 diagnostic code can be output when either a damper link or the damper is mechanically locked.

DTC No. DTC Detection Condition Trouble Area
B1442/42 Air inlet damper position sensor value does not change even if A/C amplifier operates air inlet control servo motor

  • Air inlet control servo motor

  • Air conditioning harness

  • A/C amplifier

WIRING DIAGRAM

A01616FE02

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the intelligent tester on.

    4. Operate the R/F (Recirculation/Fresh) switch.

    5. Select the item below in the Data List, and read the display on the intelligent tester.

      Data List / Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note

      Air Inlet Damper Targ Pulse

      (A/I Damp Targ Pls)

      		 Air inlet damper target pulse / Min.: 0, Max.: 255

      LHD:

      RECIRCULATION: 31 (pulse)

      FRESH: 7 (pulse)

      RHD:

      RECIRCULATION: 7 (pulse)

      FRESH: 27 (pulse)

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

    B

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    REPLACE A/C AMPLIFIER Click here

    A

  2. INSPECT AIR INLET CONTROL SERVO MOTOR


    1. Replace the air inlet 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 known good one and check that the condition returns to normal.

    2. Check for the DTC.

      Result
      Result Proceed to
      DTC B1442/42 is output A
      DTC B1442/42 is not output B

    B

    REPLACE AIR INLET CONTROL SERVO MOTOR Click here

    A

  3. 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 known good one and check that the condition returns to normal.

    2. Check for the DTC.

      Result
      Result Proceed to
      DTC B1442/42 is output A
      DTC B1442/42 is not output B

    B

    REPLACE AIR CONDITIONING HARNESS Click here

    A

    REPLACE A/C AMPLIFIER Click here