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AIR CONDITIONING SYSTEM, Diagnostic DTC:B1448

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DTC Code DTC Name
B1448 Passenger Side FACE Servo Motor Circuit
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DESCRIPTION

The No. 6 air conditioning radiator damper servo sub-assembly*1 or No. 2 air conditioning radiator damper servo sub-assembly*2 (front passenger side MODE FACE) 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 No. 6 air conditioning radiator damper servo sub-assembly*1 or No. 2 air conditioning radiator damper servo sub-assembly*2 (front passenger side MODE FACE) to the appropriate position, which controls the air outlet switching.

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
B1448 Passenger Side FACE Servo Motor Circuit

  • Diagnosis condition: During No. 6 air conditioning radiator damper servo sub-assembly*1 or No. 2 air conditioning radiator damper servo sub-assembly*2 (front passenger side MODE FACE) 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. 6 air conditioning radiator damper servo sub-assembly*1 (front passenger side MODE FACE)

  • No. 2 air conditioning radiator damper servo sub-assembly*2 (front passenger side MODE FACE)

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

 Memorized
Table 1. DTC Diagnosis Condition Combination Table
  Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition During No. 6 air conditioning radiator damper servo sub-assembly*1 or No. 2 air conditioning radiator damper servo sub-assembly*2 (front passenger side MODE FACE) 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
Tip:

If the conditions match either of these patterns, a DTC will be output.


Figure 2. for RHD: B004UMQE64
Figure 1. for LHD:
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WIRING DIAGRAM

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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.

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Tip:

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

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PROCEDURE


  1. Click here

    CHECK FOR DTC


    1. Check for DTCs.

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      1. Body Electrical > Air Conditioner > Trouble Codes


      Result
      Result Proceed to
      DTC B1448 is output A
      DTC B1448 and B1497 are output. B

  2. Click here

    CHECK AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY


    1. Check for No. 6 air conditioning radiator damper servo sub-assembly*1 or No. 2 air conditioning radiator damper servo sub-assembly*2 is installed correctly.

      OK
      No. 6 air conditioning radiator damper servo sub-assembly*1 or No. 2 air conditioning radiator damper servo sub-assembly*2 is installed correctly.

      • *1: for LHD

      • *2: for RHD

      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    • AClick here
    • B

      REINSTALL NO. 6 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLYClick here

    • C

      REINSTALL NO. 2 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLYClick here

  3. Click here

    CHECK AIR CONDITIONING RADIATOR 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

  4. Click here

    CHECK AIR CONDITIONING RADIATOR ASSEMBLY (DAMPER)


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

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      • *1: for LHD

      • *2: for RHD

    2. Operate the dampers by hand.

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

    • OKClick here
    • NG

      REPAIR OR REPLACE AIR CONDITIONING RADIATOR ASSEMBLY

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    PERFORM ACTIVE TEST USING GTS (FOOT A/O SERVO PULSE(D))


    • *1: for LHD

    • *2: for RHD

    • *3: Actually operates the No. 6 air conditioning radiator damper servo sub-assembly*1 or No. 2 air conditioning radiator damper servo sub-assembly*2 (front passenger side MODE FACE).


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

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    2. Connect the No. 6 air conditioning radiator damper servo sub-assembly*1 or No. 2 air conditioning radiator damper servo sub-assembly*2 (front passenger side MODE FOOT) connector to No. 6 air conditioning radiator damper servo sub-assembly*1 or No. 2 air conditioning radiator damper servo sub-assembly*2 (front passenger side MODE FACE).

    3. Connect the GTS to the DLC3.

    4. Turn the power switch on (IG).

    5. Turn the GTS on.

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

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


      1. Body Electrical > Air Conditioner > Active Test
        Tester Display Measurement Item Control Range Restrict Condition
        Foot A/O Servo Pulse(P)
        • for LHD:

        • No. 6 air conditioning radiator damper servo sub-assembly (front passenger side MODE FOOT) operation*3


        • for RHD:

        • No. 2 air conditioning radiator damper servo sub-assembly (front passenger side MODE FOOT) operation*3

        Min.: 128

        Max.: 383
        • for LHD:

        • Operates between 147 and 254 pulses


        • for RHD:

        • Operates between 258 and 365 pulses



      1. Body Electrical > Air Conditioner > Active Test
        Tester Display
        Foot A/O Servo Pulse(P)




      OK
      No. 6 air conditioning radiator damper servo sub-assembly*1 or No. 2 air conditioning radiator damper servo sub-assembly*2 (driver side MODE FACE) is operated.
      Result
      Proceed to
      OK
      NG

  6. Click here

    CHECK AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY


    1. Interchange the MODE FACE servo motor with MODE FOOT servo motor and connect the connectors to them.

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    2. Clear the DTCs.

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    3. Check for DTCs.

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      Result
      Result Proceed to
      DTC B1456 is output (for LHD) A
      DTC B1456 is output (for RHD) B
      DTC B1448 is output C
      DTCs are not output D
      Tip:

      Codes other than DTC B1448 and B1456 may be output at this time, but they are not related to this check.


    • A

      REPLACE NO. 6 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLYClick here

    • B

      REPLACE NO. 2 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLYClick here

    • C

      REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLYClick here

    • D

      USE SIMULATION METHOD TO CHECKClick here