Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001CO05
Model Year Start: 2019 Model: GR Corolla Prod Date Range: [06/2018 - 09/2022]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model with Automatic Air Conditioning System): B1446; Air Mix Damper Control Servo Motor Circuit (Driver Side); 2019 - 2022 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 09/2022]

DTC

B1446

Air Mix Damper Control Servo Motor Circuit (Driver Side)

DESCRIPTION

The No. 1 air conditioning radiator 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 No. 1 air conditioning radiator damper servo sub-assembly to the appropriate 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 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 No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

B1446

Air Mix Damper Control Servo Motor Circuit (Driver Side)

Air mix damper position sensor value does not change even if air conditioning amplifier assembly operates No. 1 air conditioning radiator damper servo sub-assembly

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

Memorized

(30 sec. or more)*

  • *: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.

DTC Detection Condition Combination Table

 

Vehicle Condition

Pattern 1

Pattern 2

Diagnosis Condition

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

Malfunction

Damper servo operation request signals are output but the damper position sensor value does not change

-

Damper servo operation request signals are output but the 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

HINT:

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

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • This DTC is also output for the damper link, damper lock, etc. Before performing inspection, perform servomotor initialization and check that there are no mechanical malfunctions.

    Click here 2019 - 2022 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 09/2022]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model with Automatic Air Conditioning System): INITIALIZATION

  • This DTC is also output when servomotor initialization has failed. When servomotor initialization has failed, repair any malfunctions and perform servomotor initialization again.

    Click here 2019 - 2022 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 09/2022]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model with Automatic Air Conditioning System): INITIALIZATION

PROCEDURE

1.

CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Air Conditioner / Trouble Codes.

(e) Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes

Result

Proceed to

B1497 is output

A

B1441, B1442, B1443 and B1446 are output

B

Only B1446 is output

C

A

GO TO DTC B1497

B

REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY 2019 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 01/2019]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2020 - 2021 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 06/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2021 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2020 - 09/2022]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY

C

2.

INSPECT NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (INSTALLATION CONDITION)

(a) Check that the No. 1 air conditioning radiator damper servo sub-assembly is installed correctly.

OK:

The No. 1 air conditioning radiator damper servo sub-assembly is installed correctly.

NG

INSTALL NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY CORRECTLY 2019 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 01/2019]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: REASSEMBLY 2020 - 2021 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 06/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: REASSEMBLY 2021 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2020 - 09/2022]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: REASSEMBLY

OK

3.

INSPECT NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (MOTOR, LINK, DAMPER)

(a) 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.

NG

REMOVE PINCHED WIRE HARNESS

OK

4.

INSPECT AIR CONDITIONING RADIATOR ASSEMBLY (DAMPER)

(a) Remove the No. 1 air conditioning radiator damper servo sub-assembly.

Click here 2019 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 01/2019]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2020 - 2021 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 06/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2021 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2020 - 09/2022]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY

(b) Operate the dampers by hand.

OK:

The dampers are easily operated by hand.

OK

REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY 2019 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 01/2019]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2020 - 2021 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 06/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2021 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2020 - 09/2022]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY

NG

REPLACE AIR CONDITIONING RADIATOR ASSEMBLY 2019 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 01/2019]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: REMOVAL 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: REMOVAL 2020 - 2021 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 06/2021]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: REMOVAL 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2021 - 09/2022]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: REMOVAL