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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Heating / Air Conditioning System (Except HV, W/ Auto A/C) - Diagnostic Codes (1 Of 2) >> AIR CONDITIONING SYSTEM (for Gasoline Model with Automatic Air Conditioning System) >> DTC B143B-7F: Air Inlet Damper Control Servo Motor Actuator Stuck Off [11/2023 - ] >> Description

DTC B143B-7F: Air Inlet Damper Control Servo Motor Actuator Stuck Off [11/2023 - ]: 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 No. 1 blower 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 DTC Output from Priority
B143B-7F Air Inlet Damper Control Servo Motor Actuator Stuck Off Diagnosis Condition:
  1. 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:

  1. Continuously for 30 seconds or more
  • No. 1 blower damper servo sub-assembly
  • No. 1 air conditioning radiator damper servo sub-assembly
  • Air conditioning harness assembly
  • Blower assembly
Memorized Air Conditioner A
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.