AIR CONDITIONING SYSTEM(for Automatic Air Conditioning System), Diagnostic DTC:B1442/42

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

DESCRIPTION

The damper servo sub-assembly 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 air inlet damper to any position, which controls the intake air settings (fresh, fresh/recirculation and recirculation).

Tip:

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

DTC Code

DTC Detection Condition

Trouble Area

B1442/42

The air inlet damper position does not change even if the air conditioning amplifier assembly operates the damper servo sub-assembly.

  • Damper servo sub-assembly

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

WIRING DIAGRAM

E354481E02

PROCEDURE

  1. CHECK FOR DTC

    1. Clear the DTCs (Click here).

    2. Check for DTCs (Click here).

      Table 1. Result

      Result

      Proceed to

      DTC B1442/42 is not output

      A

      DTC B1442/42 is output

      B

      DTC B1442/42 and B1497/97 are output

      C

    USE SIMULATION METHOD TO CHECK

    (Click here)

    GO TO DTC B1497/97

    (Click here)

  2. READ VALUE USING INTELLIGENT TESTER

    1. Use the Data List to check if the damper servo sub-assembly is functioning properly.

      Table 2. Air Conditioner

      Tester Display

      Measurement Item/Range

      Normal Condition

      Diagnostic Note

      Air Inlet Damper Targ Pulse

      Damper servo sub-assembly target pulse / Min.: 0, Max.: 255

      for LHD:

      • 19 (pulse): Recirculation

      • 7 (pulse): Fresh

      for RHD:

      • 7 (pulse): Recirculation

      • 25 (pulse): Fresh

      -

      Air Inlet Damper Actual Pulse

      Damper servo sub-assembly actual pulse / Min.: 0, Max.: 255

      for LHD:

      • 19 (pulse): Recirculation

      • 7 (pulse): Fresh

      for RHD:

      • 7 (pulse): Recirculation

      • 25 (pulse): Fresh

      -

      OK

      The display is as specified in the normal condition column.

      Table 3. Result

      Result

      Proceed to

      OK (When troubleshooting according to the DTC)

      A

      OK (When troubleshooting according to Problem Symptoms Table)

      B

      Both target pulse and actual pulse do not display

      C

      Target pulse displays normally, but actual pulse does not display

      D

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    (Click here)

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    (Click here)

    CHECK DAMPER SERVO SUB-ASSEMBLYClick here

  3. CHECK FOR DTC

    1. Clear the DTCs (Click here).

    2. Check for DTCs (Click here).

      OK

      DTC B1442 is not output.

    USE SIMULATION METHOD TO CHECK

    (Click here)

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    (Click here)

  4. CHECK DAMPER SERVO SUB-ASSEMBLY

    1. Replace the damper servo sub-assembly (Click here).

      Tip:

      Since the damper servo sub-assembly cannot be inspected while it is removed from the vehicle, replace the damper servo sub-assembly with a new or normally functioning one.

    2. Clear the DTCs (Click here).

    3. Check for DTCs (Click here).

      OK

      DTC B1442 is not output.

    END (DAMPER SERVO SUB-ASSEMBLY IS FAULTY)

  5. CHECK AIR CONDITIONING HARNESS ASSEMBLY

    1. Temporarily replace the air conditioning harness assembly with a new or normally functioning one (Click here).

    2. Clear the DTCs (Click here).

    3. Check for DTCs (Click here).

      OK

      DTC B1442 is not output.

    END (AIR CONDITIONING HARNESS ASSEMBLY IS FAULTY)

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    (Click here)