GPS lags after leaving underground car park

[JeffreySydney]

I'm parking in underground car parks quite often (also at home) and since day 1 my Tesla Model 3 has trouble finding the correct GPS position after leaving such a car park. It takes about 2-4 minutes for it to find its location and before that the navigation system doesn't work properly. This is highly annoying, especially when in unknown areas as you basically don't know where you should be going. I don't have the full self-driving software, but I can only imagine it being an even bigger problem then.

The local Tesla Service Centre has taken the problem seriously. They contacted Tesla US and they said it was normal behaviour. Even though, The Service Centre replaced the GPS antenna, but the problem still persists. They also did a test with another car and the behaviour is indeed similar.

Do other people encounter the same problem? And how do you deal with this? Or is there a trick to solve this?

I would expect that if my phone would be able to know where it is on this planet after leaving an underground car park, my highly sophisticated potentially-self-driving Tesla would definitely have no problems with this.

 

[Chewy3]

Mine is always 180° off when I start driving. But corrects after a couple of blocks

 

[kevwerks]

Same problem I’m experiencing

 

[JeffreySydney]

Same problem I’m experiencing

I'm glad I'm not alone! Did you also report this problem?

 

[rotus8]

When you are in an underground garage, the car cannot see the GPS satellites. When you re-emerge, it has to find them again. It takes a bit of time to do. That is just how it works, nothing to report.

 

[garu]

expected behavior, phones are like that too (Google Maps)

 

[joefee]

It takes about 5-8 minutes for nav to wake from losing the signal. I put a repair order for this and was told it was a known problem with no fix (in Jan 2020).

 

[I'm_Jp]

It doesn't help when you are driving around after the garage. It will lock in much faster if you are in a fixed position. Also tall buildings can block and/or reflect signals.

 

[JulienW]

Takes time to "find" at least 4 satellites, lock on to them then measure the time from each to calculate distance/position.

 

[Rojer Lockless]

Yeah... That's how GPS works lol. It needs line of sight. I have a SAT phone at work and if you stand under a tree it wont work most of the time.

 

[Nate977p]

I never feel like this was an issue until the last few weeks. I also moved so it could be that too...

But I think most people know how GPS works, but it's the lag. I love the Tesla GPS, only GPS in a car that really works!

But this delay has made me go back to ease when home. I pull out of the garage and Waze locks up in 15 or so seconds. The car is 1-3 minutes.

Now that may not seem like a big deal but in the city I live there are many ways to get to where you need to, but no direct way usually (you can't get there from here...). With traffic, I never know which way is best, so I rely on the GPS to help with traffic. When I pull out, of the garage I have to turn left or right, and which direction firmly dictates my path. And if people pull out behind me I can't just stop and wait for the lockup. Again these are not major issues but an annoyance.

It is very strange to me the phone locks in 15 or so seconds and car is minutes

 

[camalaio]

Let's see if my knowledge from 10 years ago is still intact and relevant.

GPS devices by themselves can either warm start (they have recent information they need on satellites) which takes under 10 seconds, or they go through a cold start process that shouldn't take much more than 30 seconds. However, the accuracy at that point may still be diminished. Tesla vehicles may be waiting on a more accurate position before snapping to it.

However, that should not normally take upwards of 2 minutes. Is this a very dense area? Do you drive out into a forest immediately?

What your car is doing prior to getting a "GPS fix" is called "dead reckoning". It's using sensor data to guess where you're going, but the errors accumulate with this method and after not too long your position is probably incorrect. I remember at a past company, some vendors we were trialing did this far better than others through a parking garage. Some ended up within 1 meter at the end, some may as well have reported that they're in the next town over.

Note regarding smartphones: These use Bluetooth and WiFi signals in addition to GPS to locate you. In more dense areas, this can be incredibly accurate. Phones can seem to get a fix faster simply because they're not only relying on GPS.

 

[Lunares]

Mine often does lag, but only for about 30 seconds or so.