AIR CONDITIONING SYSTEM, Diagnostic DTC:B1446/46

DTC Code DTC Name
B1446/46 Air Mix Damper Control Servo Motor Circuit (Driver Side)

DESCRIPTION

The No. 2 air conditioning radiator damper servo sub-assembly (driver side upper air mix) 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 No. 2 air conditioning radiator damper servo sub-assembly (driver side upper air mix) to any position. As a result, the amount of air passing through the heater core after passing through the evaporator is adjusted, and the temperature of the air blowing toward the driver seat side is controlled.

The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.

DTC Code DTC Detection Condition Trouble Area
B1446/46 Air mix damper position sensor value does not change even if air conditioning amplifier assembly operates No. 2 air conditioning radiator damper servo sub-assembly (driver side upper air mix)

  • No. 2 air conditioning radiator damper servo sub-assembly (driver side upper air mix)

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

WIRING DIAGRAM

A01FT5RE58

INSPECTION PROCEDURE

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 the auxiliary battery is disconnected, or a servo motor or the air conditioning amplifier assembly is replaced, be sure to perform servo motor initialization Click here.

  • Before disconnecting the cable form the negative (-) battery terminal or replacing the air conditioning amplifier assembly, record the last operation state of the air conditioning for each transmitter. After replacement, it is necessary to perform memory registration for each transmitter Click here.

PROCEDURE


  1. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC B1446/46 is not output A
      DTC B1446/46 is output B
      DTC B1446/46 and B1497/97 are output C

    B

    READ VALUE USING GTS Click here

    C

    GO TO DTC B1497/97 Click here

    A

    USE SIMULATION METHOD TO CHECK Click here

  2. READ VALUE USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Air Conditioner / Data List Click here.

    5. Check the value(s) by referring to the table below.

      Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Air Mix Servo Targ Pulse(D)

      No. 2 air conditioning radiator damper servo sub-assembly (driver side upper air mix) target pulse /

      Min.: 128, Max.: 383

        for RHD:

      • MAX COLD*1: 254 (pulse)

      • MAX HOT*2: 360 (pulse)


        for LHD:

      • MAX COLD*1: 258 (pulse)

      • MAX HOT*2: 152 (pulse)

      		 -
      Air Mix Servo Actual Pulse(D)

      No. 2 air conditioning radiator damper servo sub-assembly (driver side upper air mix) actual pulse /

      Min.: 128, Max.: 383

        for RHD:

      • MAX COLD*1: 254 (pulse)

      • MAX HOT*2: 360 (pulse)


        for LHD:

      • MAX COLD*1: 258 (pulse)

      • MAX HOT*2: 152 (pulse)

      		 -

      • *1: Set temperature: LO

      • *2: Set temperature: HI

      OK
      The display is as specified in the normal condition column.
      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

    B

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    D

    CHECK NO. 2 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (DRIVER SIDE UPPER AIR MIX) Click here

    A

  3. CHECK FOR DTC


    1. Clear the DTC Click here.

    2. Check for DTC Click here.

      Result
      Result Proceed to
      DTC B1446/46 is not output A
      DTC B1446/46 is output B

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    A

    USE SIMULATION METHOD TO CHECK Click here

  4. CHECK NO. 2 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (DRIVER SIDE UPPER AIR MIX)


    1. Replace the No. 2 air conditioning radiator damper servo sub-assembly (driver side upper air mix) Click here.

      Tech Tips

      Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or known good one and check that the condition returns to normal.

    2. Check for DTCs Click here.

      OK
      DTC B1446/46 is not output.

    NG

    CHECK AIR CONDITIONING HARNESS ASSEMBLY Click here

    OK

    END (NO. 2 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (DRIVER SIDE UPPER AIR MIX) WAS DEFECTIVE)

  5. CHECK AIR CONDITIONING HARNESS ASSEMBLY


    1. Replace the air conditioning harness assembly Click here.

      Tech Tips

      Since the air conditioning harness assembly cannot be inspected while it is removed from the vehicle, replace the air conditioning harness assembly with a new or known good one and check that the condition returns to normal.

    2. Check for DTCs Click here.

      OK
      DTC B1446/46 is not output.

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

    END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)