My Moto E sometimes uses up mobile data even though I have turned it off. To fix this, I added a dummy APN with random values. But still occasional data charges are incurred. I found this and am pretty sure this is the reason for my data charges as I had location services turned on since the first day. Also, the data being used is in very low amounts as I'm being charged for bytes. My question is How to be sure that it is assisted GPS that is using up my mobile data?
I have no idea how to monitor AGPS data consumption; it will probably be counted as
Android System itself using up data.
But if you do have A-GPS enabled, it will use data. From Wikipedia:
A typical A-GPS-enabled receiver will use a data connection (Internet or other) to contact the assistance server for aGPS information. If it also has functioning autonomous GPS, it may use standalone GPS, which is sometimes slower on time to first fix, but does not depend on the network, and therefore can work beyond network range, and without incurring data usage fees. Some A-GPS devices do not have the option of falling back to standalone or autonomous GPS.
Settings > Location > Location mode, you can set it to
Device only for GPS-only.
Battery saving and
High accuracy will definitely use data.