AIR CONDITIONING SYSTEM(for Manual Air Conditioning System), Diagnostic DTC:B1442

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

DESCRIPTION

The No. 1 blower 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 these signals to move the air inlet damper to the appropriate position to change 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 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

  • No. 1 blower damper servo sub-assembly

  • No. 1 air conditioning radiator damper servo sub-assembly

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

  • Blower assembly

Memorized

(30 sec. or more)*

DTC Detection Condition Combination Table
Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition No. 1 blower damper servo sub-assembly operating ○ ○
Malfunction Air inlet damper servo operation request signals are output but the air inlet damper position sensor value does not change ○ -
Air inlet damper servo operation request signals are output but the air inlet damper position sensor value is abnormal - ○
Detection Time Continuously for 30 seconds or more Continuously for 30 seconds or more
Trip Count 1 trip 1 trip

Tech Tips

If the conditions of either of these patterns are detected, a DTC will be stored.

WIRING DIAGRAM

B00708CE05

CAUTION / NOTICE / HINT

Tech Tips


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

  • When installing a damper servo motor, make sure to install it correctly.

    Click here

  • After replacing a damper servo motor, make sure to perform Servo Motor Initialization.

    Click here

PROCEDURE


  1. CHECK FOR DTC


    1. Check for DTCs.


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      Only DTC B1497 is output A
      DTC B1441, B1442 and B1443 are output B
      Only DTC B1442 is output C

    A

    GO TO DTC B1497 Click here

    B

    REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY Click here

    C

  2. INSPECT NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY (INSTALLATION CONDITION)


    1. Check that the No. 1 blower damper servo sub-assembly is installed correctly.

      OK
      The No. 1 blower damper servo sub-assembly is installed correctly.
      Result
      Proceed to
      OK
      NG

    NG

    INSTALL NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY CORRECTLY Click here

    OK

  3. INSPECT NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY (MOTOR, LINK, DAMPER)


    1. Check for a wire harness caught between the links of the motors and dampers.

      OK
      No wire harnesses are caught between the links of the motors and dampers.
      Result
      Proceed to
      OK
      NG

    NG

    REMOVE PINCHED WIRE HARNESS

    OK

  4. INSPECT NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY


    1. Remove the No. 1 blower damper servo sub-assembly.

      Click here

    2. Operate the air inlet dampers by hand.

      OK
      The air inlet dampers are easily operated by hand.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE BLOWER ASSEMBLY Click here

    OK

  5. INSPECT AIR CONDITIONING HARNESS ASSEMBLY


    1. Disconnect the No. 1 air conditioning radiator damper servo sub-assembly connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A-6 (STE2) - B-3 (sigB) Always Below 1 Ω
      A-5 (STE1) - B-2 (sigA) Always Below 1 Ω
      A-8 (M-) - B-5 (M-) Always Below 1 Ω
      A-7 (M+) - B-4 (M+) Always Below 1 Ω
      A-4 (GND) - B-1 (GND) Always Below 1 Ω
      A-6 (STE2) or B-3 (sigB) - Other terminals and Body ground Always 10 kΩ or higher
      A-5 (STE1) or B-2 (sigA) - Other terminals and Body ground Always 10 kΩ or higher
      A-8 (M-) or B-5 (M-) - Other terminals and Body ground Always 10 kΩ or higher
      A-7 (M+) or B-4 (M+) - Other terminals and Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY Click here

    OK

  6. PERFORM ACTIVE TEST USING GTS


    1. Connect the No. 1 air conditioning radiator damper servo sub-assembly connector.

    2. Connect the No. 1 blower damper servo sub-assembly connector.

    3. Connect the GTS to the DLC3.

    4. Turn the ignition switch to ON.

    5. Turn the GTS on.

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

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


      Body Electrical > Air Conditioner > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Air Inlet Damper Targ Pulse No. 1 blower damper servo sub-assembly pulse

      Min.: 128

      Max.: 383

      		 Operates between 220 to 256 pulses

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Air Inlet Damper Targ Pulse
      OK
      The No. 1 blower damper servo sub-assembly operates.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY Click here

    NG

    REPLACE NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY Click here