Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM1000000025R28
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [09/2022 - 11/2022]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (except TMC Made, and Gasoline Model, with Automatic Air Conditioning System): B1442; Air Inlet Damper Control Servo Motor; 2023 MY Corolla Corolla Hatchback GR Corolla [09/2022 - 11/2022]

DTC

B1442

Air Inlet Damper Control Servo Motor

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

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

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 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

HINT:

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

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

  • 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 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 -        ]; HEATING / AIR CONDITIONING: BLOWER UNIT: REASSEMBLY

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

    Click here 2023 MY Corolla Corolla Hatchback GR Corolla [09/2022 - 11/2022]; HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (except TMC Made, and 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 and B1443 are output

B

Only B1442 is output

C
A

GO TO DTC B1497

B

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

C

2.

READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Operate the recirculation/fresh switch.

(e) Enter the following menus: Body Electrical / Air Conditioner / Data List.

(f) Read the Data List according to the display on the Techstream.

Body Electrical > Air Conditioner > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Air Inlet Damper Targ Pulse

No. 1 blower damper servo sub-assembly target pulse

Min.: 128

Max.: 383
  • Recirculation: 256 (pulse)
  • Fresh: 220 (pulse)

No. 1 blower damper servo sub-assembly circuit malfunction

Air Inlet Damper Actual Pulse

No. 1 blower damper servo sub-assembly actual pulse

Min.: 128

Max.: 383
  • Recirculation: 256 (pulse)
  • Fresh: 220 (pulse)

No. 1 blower damper servo sub-assembly circuit malfunction

Body Electrical > Air Conditioner > Data List

Tester Display

Air Inlet Damper Targ Pulse

Air Inlet Damper Actual Pulse

OK:

When the recirculation/fresh switch is operated, the actual pulse changes following the target pulse.

Result

Proceed to

Actual pulse changes following the target pulse

A

Target pulse changes but actual pulse does not change

B

Target pulse and actual pulse do not change

C
B

GO TO STEP 4

C

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

A

3.

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

B1442 is not output

A

B1442 is output

B
A

USE SIMULATION METHOD TO CHECK

B

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

4.

REPLACE NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY

(a) Replace the No. 1 blower damper servo sub-assembly.

Click here 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 -        ]; HEATING / AIR CONDITIONING: BLOWER UNIT: DISASSEMBLY

HINT:

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.

(b) Connect the Techstream to the DLC3.

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

(d) Turn the Techstream on.

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

(f) Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes

Result

Proceed to

B1442 is not output

A

B1442 is output

B
A

END (NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY WAS DEFECTIVE)
B

5.

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

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

Click here 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY

HINT:

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.

(b) Connect the Techstream to the DLC3.

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

(d) Turn the Techstream on.

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

(f) Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes

Result

Proceed to

B1442 is not output

A

B1442 is output

B
A

END (NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY WAS DEFECTIVE)
B

6.

REPLACE AIR CONDITIONING HARNESS ASSEMBLY

(a) Replace the air conditioning harness assembly.

Click here 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY

HINT:

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.

(b) Connect the Techstream to the DLC3.

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

(d) Turn the Techstream on.

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

(f) Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes

Result

Proceed to

B1442 is not output

A

B1442 is output

B
A

END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)
B

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY