Comment by jeroenhd
Does that mean the modem used for eCall is the same that is used to transmit telemetry? Because that's a level of shitty I hadn't even considered. That said, it would go against the spirit of the law as I read it.
There are always workarounds, of course, but that does pose an annoying problem to patch.
Yes, unfortunately in all modern calls there's a single Telematics Control Unit with a modem, GPS/GNSS, eCall (where required) and whatever OEM telemetry stack.
Like you say, there are always workarounds, but none that the home-gamer can safely or legally modify without taking eCall out of compliance.