General Information

Air Conditioner

Air Conditioner - B1259 AQS Sensor Fault - General Information

Component Location





General Description

AQS (Air Quality System) keeps air inside in the most suitable state for driver. In polluted area AQS detects hazardous gas and intercepts inflow automatically, Inversely, In fresh area it allows the inflow of air to prevent the shortage of air and the accumulation of carbon dioxide. AQS sensor is located at front side of condenser and once hazardous gas is detected, it delivers the voltage signal to ECU for closing intake door.

DTC Description

The ECM sets DTC B1259 if preheating time of AQS sensor is over 40 sec or signal from AQS sensor is not within specifications.

DTC Detecting Condition





Schematic Diagram





Signal Waveform

** Voltage value of AQS sensor as a function of position of operating condition.