Car is doesn't know which way it is pointed

[Skotty]

Right now, my Model 3 often doesn't know which way it is pointing. Seems to mostly happen at the beginning of a drive. It will think it's pointed 90 to 180 degrees different than it actually is, which totally screws with navigation (and I'm sure FSD would be totally FUBAR as well). It will stay this way while driving. It knows when it's changing direction, but thinks it's pointing in an entirely different direction than it actually is. So nav just goes nuts, trying to get you to turn constantly. Today it thought I was actually driving on top of a lake, as it tries to move the pointer forward in the totally wrong direction. Anyone else had this? Anyone know how the car knows which way it is pointing? Does it have some independent compass hardware?

 

[Unclepaul]

Maybe gets direction from GPS. You will need to drive a bit for it to know which direction you are heading.

 

[Skotty]

Maybe gets direction from GPS. You will need to drive a bit for it to know which direction you are heading.

I've heard of systems that maybe work this way, but this is far from normal. I can drive several miles before it finally corrects.

 

[jjrandorin]

Right now, my Model 3 often doesn't know which way it is pointing. Seems to mostly happen at the beginning of a drive. It will think it's pointed 90 to 180 degrees different than it actually is, which totally screws with navigation (and I'm sure FSD would be totally FUBAR as well). It will stay this way while driving. It knows when it's changing direction, but thinks it's pointing in an entirely different direction than it actually is. So nav just goes nuts, trying to get you to turn constantly. Today it thought I was actually driving on top of a lake, as it tries to move the pointer forward in the totally wrong direction. Anyone else had this? Anyone know how the car knows which way it is pointing? Does it have some independent compass hardware?

I dont recall seeing another thread here in Model 3 about this.....

Note that I am not saying that I see 100% of everything, but, I do tend to see most threads in the model 3 subforum and have for a few years now. Something like this would have stuck out in my memory.

It sounds to me like a faulty GPS module. If you can video it happening ( car thinking its facing the wrong way, etc) and are still under warranty, you might be able to get it taken care of that way. If you are not still under warranty, perhaps asking them how much it would be to replace the GPS module might be a place to start.

(note that I am guessing based on symptom, I dont have any knowledge around this).

 

[gearchruncher]

I've had this before. I assume you're parking in a garage? Is your car rebooting for some reason that you know of?
If I put my car in a garage, reboot it, then the GPS can't lock on, and it can take a while to lock. Until then it's "Dead reckoning" and it gets it pretty wrong.

 

[texastodd]

Mine actually does this quite frequently in the morning coming out of my garage. Once I drive a few blocks or a minute or so, it locks on. I’ve never noticed it happening any other time when parked in the “open” as opposed to coming out of my garage.

 

[Skotty]

I have to say, I'm not a fan of these answers. It sounds like this might just be normal for the car? I do park in a garage. And there have been updates recently, so that may count as a reboot. But if this is normal, it seems like a glaring flaw in the product. If I was a FSD user, how would the car drive itself? It couldn't. At the very least, you would have to manually drive it out into the open somewhere and then let it sit there for an extended period of time until it figures itself out.

Making a determination here is kind of important, as it tells me whether or not I should just cancel the service appointment I made, as there will be nothing they can do about it.

I've never seen this issue on my S, and it's only been in the last few weeks that I've seen it on my 3. So it seemed like a new thing that needs repair.

 

[gearchruncher]

If I was a FSD user, how would the car drive itself? It couldn't. At the very least, you would have to manually drive it out into the open somewhere and then let it sit there for an extended period of time until it figures itself out.

As always, there is an insane Elon tweet to go with that:

https://twitter.com/x/status/1533179948743151616

Real FSD won't need GPS any more than a human does. Real FSD will be able to determine where in the world it is by reading signs and dead reckoning. The absolute insanity is that Elon claims what you don't need is a map, but you do need GPS? When what real humans need isn't a GPS, but just to know where they are starting on a map. The car is just going to try random roads until it makes it there?

But all of this is irrelevant because the HW in your car will never do actual FSD, and the current FSD beta is just a L2 driver assist.

If your car is doing this reliably, I'd leave it outside for a few nights and see if that fixes it. Then you'll have some better sense of what is causing it.
You didn't add anything to the car like a dashcam, usb drive, usb charger, radar detector, etc recently did you?

 

[Skotty]

As always, there is an insane Elon tweet to go with that:

https://twitter.com/x/status/1533179948743151616

Real FSD won't need GPS any more than a human does. Real FSD will be able to determine where in the world it is by reading signs and dead reckoning. The absolute insanity is that Elon claims what you don't need is a map, but you do need GPS? When what real humans need isn't a GPS, but just to know where they are starting on a map. The car is just going to try random roads until it makes it there?

But all of this is irrelevant because the HW in your car will never do actual FSD, and the current FSD beta is just a L2 driver assist.

If your car is doing this reliably, I'd leave it outside for a few nights and see if that fixes it. Then you'll have some better sense of what is causing it.
You didn't add anything to the car like a dashcam, usb drive, usb charger, radar detector, etc recently did you?

It has to use GPS/compass unless it uses some kind of turn-by-turn instruction system. And even then, it will need GPS initially to identify where it is and plan a route. It can't just count on knowing where it was last, as there could be towing, system resets, etc that make the car not know where it is on startup.

Anyway, the car not knowing which way it is pointing is a huge problem because it keeps thinking it needs to turn around, and GPS position updates are not instantaneous; it uses car speed and direction (and possibly road data too, but only if direction car is facing is close to road direction) in between the less frequent GPS position updates, so as you drive the car position shown in nav gets way different than it's actual position until the next GPS position update.

 

[gearchruncher]

It has to use GPS/compass unless it uses some kind of turn-by-turn instruction system. And even then, it will need GPS initially to identify where it is and plan a route. It can't just count on knowing where it was last, as there could be towing, system resets, etc that make the car not know where it is on startup.

Remember, Elon claims they are building a generalized, vision based AI. He's also said maps are a crutch.
Humans don't use a compass. They use their eyes. You can quickly figure out where you are and what direction you are pointed using only vision, even if the only thing you do is realize someone kidnapped you and took you somewhere else.

I'm mostly kidding around here- poking fun at how advanced and "first principles" Elon keeps claiming their system is, when the reality is just like you say, the car will be completely lost without all these assistive technologies.

 

[brkaus]

Put in a service request. Your car is broken.

 

[rrsrsr]

I had something similar happen on a BMW a few years back. They replaced the “navigation unit”… basically the computer that runs the nav system. Could be a computer hardware issue.

It sounds like you haven’t always had this problem based on your first post. did you try hard reset (foot on brake, hold both steering wheel buttons down)?

 

[brkaus]

I’m pretty sure the system has a compass and inertia sensors to help with positioning. For example in a parking garage or tunnel. Not sure which component includes those parts.

 

[gearchruncher]

I’m pretty sure the system has a compass and inertia sensors to help with positioning. For example in a parking garage or tunnel. Not sure which component includes those parts.

It has gyros and accels. However, no compass. Compasses inside a metal car with 800A currents, inside parking garages with rebar, in urban canyons are basically worthless.
So it works fine if it already has a direction and can do inertial estimation from that, but without GPS at some point to get a direction, it is lost.

 

[Skotty]

It has gyros and accels. However, no compass. Compasses inside a metal car with 800A currents, inside parking garages with rebar, in urban canyons are basically worthless.
So it works fine if it already has a direction and can do inertial estimation from that, but without GPS at some point to get a direction, it is lost.

This would be consistent with the behavior assuming it was having difficulty doing the initial determination of what direction it is facing. Because it would remain 90 to 180 degrees off regardless of turns. So the question is what metrics are used to determine what way it is facing initially, and why was it taking so long for it to make that determination.

 

[drtimhill]

Right now, my Model 3 often doesn't know which way it is pointing. Seems to mostly happen at the beginning of a drive. It will think it's pointed 90 to 180 degrees different than it actually is, which totally screws with navigation (and I'm sure FSD would be totally FUBAR as well). It will stay this way while driving. It knows when it's changing direction, but thinks it's pointing in an entirely different direction than it actually is. So nav just goes nuts, trying to get you to turn constantly. Today it thought I was actually driving on top of a lake, as it tries to move the pointer forward in the totally wrong direction. Anyone else had this? Anyone know how the car knows which way it is pointing? Does it have some independent compass hardware?

Does the compass display on the map look correct?

 

[gearchruncher]

Does the compass display on the map look correct?

Pretty sure that's exactly what he means by "pointed 90 to 180 degrees off."
The "compass" display is GPS ground track, augmented by intertials when GPS is denied. It's not a real compass.

 

[GtiMart]

GPS only gives position, not direction, and it takes time before it gives a relatively precise position. Initially it calculates a pretty big "area" of possible positions until it syncs with enough satellites. Then the car needs a few valid, precise positions in a row before it can infer direction. If you're in a garage it might take a while before the GPS unit syncs with enough satellites to figure it out.
If you leave the car parked outside, do you have something reasonable when you get in the car and start driving?

 

[gearchruncher]

Then the car needs a few valid, precise positions in a row before it can infer direction.

It's technically possible to estimate direction with a very low precision position estimation as long as the vehicle is moving. It's irrelevant in auto navigation applications however, given you need both accurate position and direction to be useful.

 

[nharwood]

I had this happen with a Jeep in the past, but based on someone elses comment that the Tesla does not have a magnetometer this probably wont work but I went to an open parking lot and drove in a slow 360 degree circle in one direction and then in the other direction and it solved my problem. But that was definitely to help calibrate the magnetic ‘compass.’ I suggest a service ticket if nothing else works. It doesn’t sound like it is operating properly.

By chance do you live in a downtown area with tall building, or mountains that could block GPS satellite signal?