Have just been told by JLR support that my Telemetric Control Unit has stopped working as the current TCU is no longer capable of using the latest software and that is why it is showing on the app as asleep.
So I need to go to main dealer and have new TCU installed. Really!
Could I ask if any other MY16 / MY17 owners have a similar issue.

Secondly, does anyone know if new TCU is plug and play ?

I recently acquired my MY17 L405 and have the same issue... have been unable to connect via the Remote app. App states 'The onboard telematics system is currently in sleep mode'. TV also has stopped working since the S22A update.

Tempting fate but, my MY16 is still showing fine on the app.

Well, just checked my remote app and lo and behold it now works, so much for JLR support saying I had to get new unit. That’s £1450 saved.

I had few problems with mine at the start but found a ‘3’ data only SIM card minimum 24months and deleting the app, then re loading the app, logging in sorted it. Customer services said as you did a visit was required 2021 SVautobiography Dynamic Black ( Black wheels need to go )
1997 C140 Mercedes Benz CL500