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DTC B149A: Communication Malfunction (Rear Bus Ic) [12/2019 - 10/2022]: Description

The No. 2 air conditioning harness assembly connects the air conditioning amplifier assembly and the servo motors.

The air conditioning amplifier assembly supplies power and sends operation instructions to each servo motor through the No. 2 air conditioning harness assembly.

Each servo motor sends damper position information to the air conditioning amplifier assembly.

DTC No. Detection Item DTC Detection Condition Trouble Area Memory
B149A Communication Malfunction (Rear Bus Ic) Error or open in communication line between air conditioning amplifier assembly and any of the following servo motors.
  • Rear mode damper servo sub-assembly
  • Rear air mix damper servo sub-assembly
  • No. 2 air conditioning harness assembly
  • Air conditioning amplifier assembly
  • Harness or connector
 Memorized
(10 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.

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