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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/ Manual A/C) - Diagnostic Codes, Circuit Tests & Symptom Tests >> AIR CONDITIONING SYSTEM (for Gasoline Model with Manual Air Conditioning System) >> DTC B1442: Air Inlet Damper Control Servo Motor Circuit [12/2019 - 10/2022] >> Description

DTC B1442: Air Inlet Damper Control Servo Motor Circuit [12/2019 - 10/2022]: 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 the 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 Circuit 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
  • Blower 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.