DTC B143B-7F: Air Inlet Damper Control Servo Motor Actuator Stuck Off [11/2021 - ]: Description
WARNING: This page is about a different car, the 2025 Lexus NX 350h, 2024 Lexus NX 350h, 2023 Lexus NX 350h, and 2022 Lexus NX 350h. However, it is still accessible from the selected car via links, so may be relevant.
The No. 3 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. 3 air conditioning radiator damper servo sub-assembly to the appropriate position to change the air inlet mode (fresh, recirculation/fresh, and recirculation).
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory |
|---|---|---|---|---|
| B143B-7F | Air Inlet Damper Control Servo Motor Actuator Stuck Off | Diagnosis Condition:
Malfunction:
Detection Time:
|
|
Memorized |
DTC DETECTION CONDITION COMBINATION TABLE
| Vehicle Condition | |||
|---|---|---|---|
| Pattern 1 | Pattern 2 | ||
| Diagnosis Condition | No. 3 air conditioning radiator 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.