(KTLA) – Millions of vehicles lost wireless functionality — including SOS buttons such as OnStar — as AT&T this week became the first major service provider to shut down its 3G network.

The demise of 3G networks comes as wireless providers clear bandwidth for state-of-the-art 5G service. Along with vehicle connections, older cellphones and some home-security systems are now becoming obsolete.

AT&T’s 3G network went dark on Tuesday. T-Mobile’s is scheduled to vanish in stages by summer. Verizon’s will stick around through the end of 2022 but will grow increasingly unreliable.

This has been in the works for years. As I wrote for the Los Angeles Times, the big wireless service providers started introducing 5G on a limited basis in 2018.

From a service perspective, you can expect faster connections with 5G and far fewer lags in data streams. Watching online video, for example, will be much, much smoother.

Your monthly bill, meanwhile, will probably go up, at least after introductory 5G rates expire.

If your current phone or vehicle receives LTE signals, that means it’s 4G-compatible. Unless you upgrade, you won’t be part of the 5G revolution, but your service should continue for the immediate future.

Most Americans will find their service uninterrupted. Nearly 300 million cellphones are in use nationwide, the vast majority operating on 4G networks.

But for the 10 million or so that still rely on 3G, which debuted in 2002, they’re now becoming bricks.

Owners of Teslas, Hondas, Nissans and other vehicles with older wireless systems will lose not just emergency calling but also some infotainment and other features.

Needless to say, this can impact the resale value of such vehicles.

Consumer Reports has compiled a list of cars and trucks with potentially outdated 3G systems. Click here to see if your vehicle is affected.

What can you do? At this point, it’s unclear if any automakers will upgrade customers’ wireless systems. Most seem to be watching to see how many people are affected and how big a stink they make.

Your best bet, as with cellphones, may be to purchase a newer model — and enjoy it for as long as you can until it too becomes high-tech roadkill.