Custom SIM card in Tesla Model 3 2024, Tesla Model Y 2025 and Cybertruck

58 LorenDB 30 5/12/2025, 1:04:59 AM olegkutkov.me ↗

Comments (30)

layoric · 13h ago
> Waking up the car The native Tesla mobile application wakes the car by sending an SMS to the internal SIM card number. This number is registered in the Tesla database. When using a custom external SIM, you must manually send an SMS (with arbitrary text) to your SIM number. Any SMS will wake up the car, and it will be available via the Tesla mobile app. Don’t forget to unsubscribe your SIM from any newsletters to avoid false wakeups and extra power drain.

Wow..

kimos · 3h ago
I think about this every time my car is slow to wake or doesn’t wake when in a spot with poor signal, it’s SMS fuckery.

Regardless of all their problems now, decisions like this that made Tesla successful. Need a low power always on way to send the car a signal to wake from a mobile device? Don’t invent and build some complicated hardware and protocol, just use SMS and a small cell phone board.

vld_chk · 12h ago
Does it mean that if internal DB of internal numbers will be leaked anytime in the future, it will give to anyone power to wake up all Tesla cars in a few clicks?
GeorgeCurtis · 12h ago
Certainly sounds like it.
boredatoms · 13h ago
Does this mean spam sms could be waking up my car even without a sim swap?
bobmcnamara · 13h ago
If they did it right, these would be setup with their own range of numbers that can't be routed from anywhere outside of their carrier and servers.

Cell companies have a word for a setup like this but it escapes me.

2bluesc · 12h ago
Closed User Group (CUG)?
systemswizard · 12h ago
Tesla has a custom APN
fresh_geezer · 8h ago
APN does not influence SMS (nor phone number routing) though.
0x38B · 12h ago
dawnerd · 13h ago
Wonder if this could work with the Calyx sim now that they have BYOD.
gruez · 13h ago
As per the OP, there's no advantage of doing this if you're in a region that Tesla officially supports, because Tesla already has free connectivity with the free built-in SIM. The only use of this is if you're in a region where Tesla isn't supported, and thus Tesla won't have the necessary roaming agreements for its built-in SIM to work. The Calyx sim only supports US and Puerto Rico, so it's of no use. There's no privacy benefit either, because the phone can still upload your location/telemetry regardless of what SIM you're using.
dawnerd · 24m ago
Maybe I misunderstood and assumed this would allow premium connectivity as Tesla is no longer footing the data bill. But if that’s not the case then ya it’s kinda pointless.
NewJazz · 10h ago
Wouldn't this be relevant for those who want to decouple their car from Tesla tracking? Obviously only a partial solution, but still.
gruez · 1h ago
How are you decoupling from Tesla tracking by using your own SIM? The car has a built-in GPS so even if it can't track you by cell tower pings, it can upload your location to Tesla servers all day long.
NewJazz · 26m ago
I'm sorry did you miss the part where I said "obviously, only a partial solution"?
tazjin · 13h ago
I flagged this because the site runs some Javascript for me that attempts a redirect to a spam page (which uBlock caught). Looks like there might be some malicious code injected there.
grishka · 13h ago
I can reproduce this. It might be only happening for Russian IPs because it does not happen if I use my VPN.

(The author is Ukrainian, so nothing surprises me at this point)

NewJazz · 13h ago
I can't reproduce that.
redundantly · 13h ago
Ditto. Viewed it just fine via Safari on iOS. I'm guessing GP accidentally triggered the form for the comment system.
ThePowerOfFuet · 12h ago
Try with a Russian IP.
mgiampapa · 12h ago
No thank you, I have all of Russia/China/Belarus's normal IP space blocked at the router in both directions. I don't expect it will protect me from anything, but it's a great way to not accidentally step into bullshit.