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 mode selection No. 1 blower damper servo sub-assembly 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 Air Inlet Damper Control Servo Motor Circuit

  • Diagnosis condition: During No. 1 blower damper servo sub-assembly operation

  • Malfunction status: The damper servo operation request signal is output but the position information of the servo does not change or servo is malfunctioning

  • Detection time: Continuously for 30 seconds or more

  • No. 1 blower damper servo sub-assembly

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

 Memorized
DTC Detection Condition Combination Table
Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition During No. 1 blower damper servo sub-assembly operation ○ ○
Malfunction Status The damper servo operation request signal is output but the position information of the servo does not change ○ -
The damper servo operation request signal is output but the position information of the servo is malfunctioning - ○
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 match either of these patterns, a DTC will be output.

WIRING DIAGRAM

Figure 1. for 4 Zone Type:

B006AWLE47

Figure 2. for Dual Type:

B006AWLE97

CAUTION / NOTICE / HINT

Note


  • 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.

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

  • When the servo motor is replaced, be sure to perform servo motor initialization.

    Click here

Tech Tips

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

PROCEDURE


  1. CHECK FOR DTC


    1. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1442 is output A
      DTC B1442 and B1497 are output. B

    B

    GO TO DTC B1497 Click here

    A

  2. CHECK NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY


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

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

    NG

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

    OK

  3. CHECK 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. CHECK BLOWER ASSEMBLY (DAMPER)


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

      Click here

    2. Operate the dampers by hand.

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

    NG

    REPAIR OR REPLACE BLOWER ASSEMBLY

    OK

  5. PERFORM ACTIVE TEST USING GTS (AIR MIX SERVO TARG PULSE (P))


    • *1: for LHD

    • *2: for RHD (for 4 Zone Type)

    • *3: for RHD (for Dual Type)

    • *4: Actually operates the No. 1 blower damper servo sub-assembly


    1. Remove the No. 4 air conditioning radiator damper servo sub-assembly*1, No. 6 air conditioning radiator damper servo sub-assembly*2 or No. 2 air conditioning radiator damper servo sub-assembly*3.

      Click here

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

      Click here

    3. Connect the No. 1 blower damper servo sub-assembly connector to No. 4 air conditioning radiator damper servo sub-assembly*1, No. 6 air conditioning radiator damper servo sub-assembly*2 or No. 2 air conditioning radiator damper servo sub-assembly*3 (front passenger side upper air mix).

    4. Connect the GTS to the DLC3.

    5. Turn the engine switch on (IG).

    6. Turn the GTS on.

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

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


      Body Electrical > Air Conditioner > Active Test
      Tester Display Measurement Item Control Range Restrict Condition
      Air Mix Servo Targ Pulse(P)

        for LHD:

      • No. 4 air conditioning radiator damper servo sub-assembly (front passenger side upper air mix) operation*3


        for RHD:

      • No. 6 air conditioning radiator damper servo sub-assembly (front passenger side upper air mix) operation (for 4 Zone Type)*4

        No. 2 air conditioning radiator damper servo sub-assembly (front passenger side upper air mix) operation (for Dual Type)*4

      Min.: 128

      Max.: 383

        for LHD:

      • Operates between 186 to 258 pulses


        for RHD:

      • Operates between 254 to 326 pulses

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Air Mix Servo Targ Pulse(P)
      OK
      No. 1 blower damper servo sub-assembly is operated.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY Click here

    NG

  6. CHECK NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY


    1. Interchange the front passenger side upper air mix servo motor with blower servo motor and connect the connectors to them.

      Click here

      Click here

    2. Clear the DTCs.

      Click here

    3. Check for DTCs.

      Click here

      Result
      Result Proceed to
      DTC B1441 is output A
      DTC B1442 is output B
      DTCs are not output C

      Tech Tips

      Codes other than DTC B1441 and B1442 may be output at this time, but they are not related to this check.


    A

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

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    C

    USE SIMULATION METHOD TO CHECK Click here