Inspection

1.	Ignition "ON"

2.	Using the scan tool.

3.	Check the output voltage of AQS between terminals 2 and 3. [Specification] Condition Output signal Fresh/recirculation Normal condition 3.8 ~ 4.8V Fresh Hazardous gas detection 0.4 ~ 1.4V Recirculation

4.

AQS diagnosis and fail safe * AQS Sensing OPEN/SHORT : Sensingafter IG ON. * AQS Sensing FAIL (abnormal output) : Sensing after40sec IN ON. * FAIL SAFE Funcion : AQS when AQS OPEN/SHORT andFAIL. When IG is turned ON, AQS heats for 35±2 seconds, it will output below 2.5±0.3V voltage during this time.

Replacement

1.	Disconnect the negative (-) battery terminal.

2.	Remove the front bumper (Refer to BD group-Front bumper).

3.	Remove the AQS (B) after loosening the mounting bolts.

4.	Installation is the reverse order of removal.