DTC B1441: Air Mix Damper Control Servo Motor Circuit (Passenger Side); DTC B1443: Air Outlet Damper Control Servo Motor Circuit; DTC B1446: Air Mix Damper Control Servo Motor Circuit (Driver Side) [06/2018 - ]: Description
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2024 Lexus ES 350, 2024 Lexus ES 250, 2023 Lexus ES 350, 2023 Lexus ES 250, and 2022 Lexus ES 350. However, it is still accessible from the selected car via links, so may be relevant.
- B1441: The No. 1 air conditioning radiator damper servo sub-assembly (front passenger side 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 these signals to move the No. 1 air conditioning radiator damper servo sub-assembly (front passenger side air mix) to the appropriate position. This adjusts the amount of air passing through the heater core after passing the evaporator and controls the temperature of the output air. The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.
- B1443: The No. 1 air conditioning radiator damper servo sub-assembly (mode) 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 outlet damper 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.
- B1446: The No. 1 air conditioning radiator damper servo sub-assembly (driver side 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 these signals to move the No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) 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 |
|---|---|---|---|---|
| B1441 | Air Mix Damper Control Servo Motor Circuit (Passenger 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 (front passenger side air mix) |
|
Memorized (30 sec. or more)* |
| B1443 | Air Outlet Damper Control Servo Motor Circuit | Air outlet damper position sensor value does not change even if air conditioning amplifier assembly operates No. 1 air conditioning radiator damper servo sub-assembly (mode) |
|
Memorized (30 sec. or more)* |
| 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 (driver side air mix) |
|
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.