Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

What happens if the GPS fails? Here's what I've experienced.

This site may earn commission on affiliate links.
I took my car in for service for a radar alignment issue a month ago. Upon picking up the car, the GPS thought my car was at home in the garage and didn't move as I was driving. I don't know why that would be the location as it knew that I had dropped the car off at the service center 15 miles away. I contacted Tesla tech support on the phone and they had me do three difference resets including a full power off, but none helped. I drove about 30 miles over the next 4 days before the GPS suddenly realized where the car was again. I did not activate autopilot during this time, but traffic light awareness and other driver assistance features worked fine. P.S. The Tesla app matched the location in the car but would show the car, for example, going 70 MPH while being stationary "in my garage".

It worked for a week until I drove through the 99 tunnel in Seattle. Upon exiting the tunnel, the car was about 2 miles off on its location, but continued tracking as the car moved. This caused MANY issues. Every time the location on the map crossed or was near a street (two miles south from where I actually was driving), the speed limit sign on the screen would change. If I was on the freeway at the time with autopilot on and the incorrect GPS location crossed a surface street with a 25 MPH speed limit, the car would SLAM on the brakes suddenly thinking that the speed limit had dropped from 60 or 70 MPH to 25. I found out the hard way a few times. After another week or so, the GPS was suddenly working again.

Fast forward another week, and we took a ferry to Orcas Island. The GPS worked all the way there, but on the way back, the car lost its location upon disembarking the ferry and thought it was about 30 miles to the northwest AND it continued to track the car's movements but was about 100 degrees off on the direction. When I drove south, the car was tracking to the ENE. The car read a speed limit sign exiting the ferry that said 15 MPH and never once changed it over the 100 mile drive home. This kept me from enabling autopilot or even simple cruise control as both would quickly flash an error that said "safety convenience features were degraded". This also seemingly caused another safety issue. Once the car had no idea where it was, the traffic light awareness began thinking EVERY overcrossing on the freeway was a traffic light and would slam on the brakes if I did not press on the accelerator ahead of time to maintain the speed. This was clearly dangerous, but fixable if autopilot/cruise control are not used. A few days later, suddenly the GPS began working again.

Then on Friday, I went to get something out of the car, and it was locked while in the garage despite having the car set to stay unlocked while at home. I knew something was wrong. Upon opening the door, the car thought it was in northern Alberta, Canada. Oddly, the app correctly showed it to be in my garage. I did multiple restarts and power offs, and eventually the GPS came back to life again. I left on a road trip that afternoon to Portland, and the GPS never moved. It stayed in my garage for the entire 200 mile trip south. For the first time, the display showed an error icon for poor GPS signal (pictured below). Autopilot or simple cruise control would not enable unless I was going 65 MPH or slower, but it was difficult to use as the car again thought that every overpass was a traffic light and would slam on the brakes after a last second warning that it was "stopping for a traffic light control in 300 feet". I did multiple drives of 10-40 miles around the Portland area with the GPS and app still showing the car in my garage, and the car rarely saw traffic lights EXCEPT freeway overpasses. It seems the car relies on GPS data to validate that a traffic light exists that it can see. On the drive home yesterday, the GPS suddenly began working again 30 miles from home out of nowhere.

I have a mobile tech appointment on Wednesday to hopefully fix this. Here are the issues and oddities that I have noticed:

1. The settings for keeping the car unlocked at home along with sentry mode being disabled while at home kept BOTH non-operational whenever the car incorrectly thought it was at my house, so it was unlocked and not recording video the whole weekend before I realized that was happening.
2. If the car loses GPS signal, it incorrectly thinks that overpasses are traffic light controls and attempts to slam on the brakes to stop out of nowhere. I'm guessing it has something to do with an overhead horizontal object about to pass over the car similar to how a traffic light would be viewed? (I did not try to capture this on video yet)
3. Autopilot and cruise control cannot be used without a GPS signal as the car is relying on the GPS for speed limit data despite having the ability to read the speed limit signs now. If it reads 70 MPH on the freeway, it may suddenly revert to the incorrect GPS data and slam on the brakes thinking you're in a 25 MPH zone as it did to me over and over.
4. Odometer issues - I called Tesla tech support multiple times about this issue. One of the ID verifications they do is by asking the current mileage on the car. The last two times I was asked, my # was off. I checked the odometer in the car vs the app, and the app is reporting 510 miles more than the in-car reading now. That is roughly the # of miles I have driven with the car having no idea where it was located. Does that mean the car is using GPS to track it's odometer reading, and what does this mean for the warranty?
5. What happens if a car with full self driving loses GPS signal? Does it slam on the brakes in the middle of the freeway and cause an accident thinking an overpass is a traffic light or slow down to 25 MPH when the signs clearly say 70 MPH because it thinks it is on the frontage road or, worse, a thousand miles away in another country?

First time I have seen this indicator. The message that appeared the first time it came up said something about poor GPS accuracy.
IMG_20201023_191153.jpg


Clearly this is not a 25 MPH zone. It was on I-5 near Arlington, WA.
IMG_20201023_195225.jpg


This beautiful drive had the GPS take me up and over Mount Baker and into southern BC at one point. I was actually 100 miles to the SSW.

IMG_20201018_131052.jpg
 
  • Informative
  • Like
Reactions: Amr Wahbi and SO16
I had somewhat similar issue, when my MCU1 was failing and needed a reset. Odometer was not recording mileage, whenever parked car kept defaulting to another GPS location that I used weeks ago. After I've reset the car to factory defaults - it fixed itself.
 
I took my car in for service for a radar alignment issue a month ago. Upon picking up the car, the GPS thought my car was at home in the garage and didn't move as I was driving. I don't know why that would be the location as it knew that I had dropped the car off at the service center 15 miles away. I contacted Tesla tech support on the phone and they had me do three difference resets including a full power off, but none helped. I drove about 30 miles over the next 4 days before the GPS suddenly realized where the car was again. I did not activate autopilot during this time, but traffic light awareness and other driver assistance features worked fine. P.S. The Tesla app matched the location in the car but would show the car, for example, going 70 MPH while being stationary "in my garage".

It worked for a week until I drove through the 99 tunnel in Seattle. Upon exiting the tunnel, the car was about 2 miles off on its location, but continued tracking as the car moved. This caused MANY issues. Every time the location on the map crossed or was near a street (two miles south from where I actually was driving), the speed limit sign on the screen would change. If I was on the freeway at the time with autopilot on and the incorrect GPS location crossed a surface street with a 25 MPH speed limit, the car would SLAM on the brakes suddenly thinking that the speed limit had dropped from 60 or 70 MPH to 25. I found out the hard way a few times. After another week or so, the GPS was suddenly working again.

Fast forward another week, and we took a ferry to Orcas Island. The GPS worked all the way there, but on the way back, the car lost its location upon disembarking the ferry and thought it was about 30 miles to the northwest AND it continued to track the car's movements but was about 100 degrees off on the direction. When I drove south, the car was tracking to the ENE. The car read a speed limit sign exiting the ferry that said 15 MPH and never once changed it over the 100 mile drive home. This kept me from enabling autopilot or even simple cruise control as both would quickly flash an error that said "safety convenience features were degraded". This also seemingly caused another safety issue. Once the car had no idea where it was, the traffic light awareness began thinking EVERY overcrossing on the freeway was a traffic light and would slam on the brakes if I did not press on the accelerator ahead of time to maintain the speed. This was clearly dangerous, but fixable if autopilot/cruise control are not used. A few days later, suddenly the GPS began working again.

Then on Friday, I went to get something out of the car, and it was locked while in the garage despite having the car set to stay unlocked while at home. I knew something was wrong. Upon opening the door, the car thought it was in northern Alberta, Canada. Oddly, the app correctly showed it to be in my garage. I did multiple restarts and power offs, and eventually the GPS came back to life again. I left on a road trip that afternoon to Portland, and the GPS never moved. It stayed in my garage for the entire 200 mile trip south. For the first time, the display showed an error icon for poor GPS signal (pictured below). Autopilot or simple cruise control would not enable unless I was going 65 MPH or slower, but it was difficult to use as the car again thought that every overpass was a traffic light and would slam on the brakes after a last second warning that it was "stopping for a traffic light control in 300 feet". I did multiple drives of 10-40 miles around the Portland area with the GPS and app still showing the car in my garage, and the car rarely saw traffic lights EXCEPT freeway overpasses. It seems the car relies on GPS data to validate that a traffic light exists that it can see. On the drive home yesterday, the GPS suddenly began working again 30 miles from home out of nowhere.

I have a mobile tech appointment on Wednesday to hopefully fix this. Here are the issues and oddities that I have noticed:

1. The settings for keeping the car unlocked at home along with sentry mode being disabled while at home kept BOTH non-operational whenever the car incorrectly thought it was at my house, so it was unlocked and not recording video the whole weekend before I realized that was happening.
2. If the car loses GPS signal, it incorrectly thinks that overpasses are traffic light controls and attempts to slam on the brakes to stop out of nowhere. I'm guessing it has something to do with an overhead horizontal object about to pass over the car similar to how a traffic light would be viewed? (I did not try to capture this on video yet)
3. Autopilot and cruise control cannot be used without a GPS signal as the car is relying on the GPS for speed limit data despite having the ability to read the speed limit signs now. If it reads 70 MPH on the freeway, it may suddenly revert to the incorrect GPS data and slam on the brakes thinking you're in a 25 MPH zone as it did to me over and over.
4. Odometer issues - I called Tesla tech support multiple times about this issue. One of the ID verifications they do is by asking the current mileage on the car. The last two times I was asked, my # was off. I checked the odometer in the car vs the app, and the app is reporting 510 miles more than the in-car reading now. That is roughly the # of miles I have driven with the car having no idea where it was located. Does that mean the car is using GPS to track it's odometer reading, and what does this mean for the warranty?
5. What happens if a car with full self driving loses GPS signal? Does it slam on the brakes in the middle of the freeway and cause an accident thinking an overpass is a traffic light or slow down to 25 MPH when the signs clearly say 70 MPH because it thinks it is on the frontage road or, worse, a thousand miles away in another country?

First time I have seen this indicator. The message that appeared the first time it came up said something about poor GPS accuracy.
View attachment 602589

Clearly this is not a 25 MPH zone. It was on I-5 near Arlington, WA.
View attachment 602590

This beautiful drive had the GPS take me up and over Mount Baker and into southern BC at one point. I was actually 100 miles to the SSW.

View attachment 602591
Hello RPO,

I’m experiencing the same exact GPS issue identical to what you described, where the location inaccurately shows my car in the middle of the sea, similar to the photo you shared.

Could you please share how you managed to resolve this issue? I’m keen to understand both the root cause and the steps taken for the resolution. Any insights or advice you could provide would be greatly appreciated.

My Car : 2018 Model S HW3.0 MCU2.5 , SW version 2024.2.7

Looking forward to your response.
 
Hello RPO,

I’m experiencing the same exact GPS issue identical to what you described, where the location inaccurately shows my car in the middle of the sea, similar to the photo you shared.

Could you please share how you managed to resolve this issue? I’m keen to understand both the root cause and the steps taken for the resolution. Any insights or advice you could provide would be greatly appreciated.

My Car : 2018 Model S HW3.0 MCU2.5 , SW version 2024.2.7

Looking forward to your response.

Good question....I honestly don't remember, but Tesla did not repair/replace anything. I believe it rectified itself after a while, but it happened for something like a week from what I remember Restarting the main screen did nothing to fix it too.
 
Good question....I honestly don't remember, but Tesla did not repair/replace anything. I believe it rectified itself after a while, but it happened for something like a week from what I remember Restarting the main screen did nothing to fix it too.
USB Hub Connections: Could you recall what devices were connected to your USB hub during the time you experienced GPS signal issues?

There's speculation in other forums that certain devices (like USB hubs, specific SSD models, wireless chargers, and even toll passes) might interfere with GPS signals and cause disruptions.
 
USB Hub Connections: Could you recall what devices were connected to your USB hub during the time you experienced GPS signal issues?

There's speculation in other forums that certain devices (like USB hubs, specific SSD models, wireless chargers, and even toll passes) might interfere with GPS signals and cause disruptions.

Possibly two USB drives...one for the cameras and one for music.
 
I picked up a new 2023 Model S in January of this year. (to replace my 2017 S; we've since then also gotten a 2024 X to replace our 2018 X).

Within a week of ownership the new S starting having GPS issues. At that time, I had an EZ-PASS transciever mounted on the windshield and a USB C wire plugged into the console (and the Tesla-supplied USB stick in the glove compartment.

The GPS issues started with the message "Poor GPS location accuracy" when I had Autopilot engaged. Two days later the car showed on the map offset about 30' from where it really was. The two further days and the GPS location stopped updating completely; the car showed the car in the garage even as I headed down the highway.

And, as the OP in this thread points out, it is really weird to drive it when the GPS is misbehaving.

Suspecting that they might claim an issue with the EZ-PASS transciever, I took it out of the car and disconnected the USB cable. The problems persisted.

I got a service appointment for my 10 day old car, which took another 10 days. When I dropped it off at the service center, the car still showed it as being in my garage. That clinched the problem as being within the GPS; they suspected the antenna.

It took them a few days to find a cut in the GPS antenna, and then over a week for the part to arrive. They put the car back together, and while doing do damaged the headliner. So they had to order a replacement. That wook 10 more days. Overall, the brand new car was in service for 4 weeks.

I got the car back and initially the GPS was fine. I immediately found a damaged trim piece in the trunk and opened a mobile service for that.

I put the EZ-PASS back into the car. I put the USB cable back. I also put a right angle USB A adapter in the glove compartment, because I was worried about the papers in there leaning on the Tesla USB stick.

Two weeks later I got my first instance of "Poor GPS location accuracy". They'd appear and then clear up in 5 to 10 minutes (or so). I started to document them by taking pictures (for the timestamp).

Then the trim piece on the driver's A pillar fell off. So I opened a new mobile service for that. (it looked like it was damaged in the reassembly of the interior).

A week later I left the house and the GPS was stuck on my garage for the first 2 miles of the trip, after which it jumped to the real location but with a "Poor GPS location accuracy" warning. This is when I opened my most recent service appointment (having 5 instances of just the poor location warning).

I just got back from that service. The tech claimed the USB right angle adapter in the glove compartment was to blame. So I've removed it from my car, and am back to documenting issues with the GPS. I'm hoping they don't recur.
 
NEW update: I was chasing Tesla for the "Root Cause of the issue" and not a resolution. Finally, they admitted (attached) that they received multiple affected cars, and they identified the root cause which I suspect a software issue and they promised to fix it in few days

My Car : 2018 Model S HW3.0 MCU2.5 , SW version 2024.8.7
 

Attachments

  • GPS.jpg
    GPS.jpg
    104 KB · Views: 9