This patch improves Bluetooth car audio, charging in Retail Mode, and more.
If you've been enjoying Android 9 Pie on one of the Pixel or Pixel 2 devices, large or small, it's about to get even better with its first security patch. Dated for September 5, the OTA files and firmware images are already available on Google's site in case you don't want to wait (as long as you're comfortable with manually flashing software updates).
The September 2018 security patch brings with it a few software fixes, namely improving Bluetooth audio quality over car speakers, along with improving charging efficiency for Pixel phones in Retail Mode (the demo loops running on phones at carrier stores) and better software version reporting.
This security patch also includes some changes that keep potentially malicious installed apps from reading data generated by other apps.
If you're feeling impatient and don't mind flashing the update yourself, you can visit Google's developer site to download the appropriate OTA and factory images. Otherwise, you should be seeing the update come to your Pixel device within the next couple of days.