Since the latest software update, my "max speed" on autopilot is randomly changing (both down AND up) when driving on the highway where the speed should of course be fixed. This is happening again and again on the same drive. I was on the LIE today (55MPH, no construction etc) and the set speed dropped from 65 to 35 without warning and without me touching the control wheel. VERY DANGEROUS! It happened at least a dozen times on my drive, I even took a video. It also jumped up above its set point without my input. I was also noticing (although not correlated to the speed changes) that the car was getting the speed limit wrong for the highway multiple times. Is this a known issue with the new software? I also had my steering wheel replaced a month ago, could this be related?
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Autopilot set speed randomly changes
- Thread starter nyc-dad
- Start date
TresLA
Member
This is usually because of the GPS being off and therefore the car thinks it’s on a different road. If this happens again, check the map and see if your car location icon appears to be somewhere other than where you are. Or have a passenger take a video that includes the map.
In other words, autopilot isn’t doing anything wrong. It’s just being told wrongly which road you’re on.
Anecdotally, this has happened to most everyone I know maybe once or twice (especially when coming out of an underground parking garage or otherwise poor GPS signal location). If it’s happening regularly and while out in the open for awhile before, then you should setup a service appt in the app.
In other words, autopilot isn’t doing anything wrong. It’s just being told wrongly which road you’re on.
Anecdotally, this has happened to most everyone I know maybe once or twice (especially when coming out of an underground parking garage or otherwise poor GPS signal location). If it’s happening regularly and while out in the open for awhile before, then you should setup a service appt in the app.
When these set speed changes occur, is the speed limit changing on the display, or just the set speed? If the speed limit is changing, then this might be a GPS issue (is your location shown correctly?) or possibly a software issue, though I have not seen other reports of this issue, so I'm suspecting not a software problem.
If the speed limit is correct, and only the set speed is changing, then I would suspect an issue with the right scroll wheel on your steering wheel. What led you to replace the old one? Was this a replacement for a faulty unit with a new steering wheel by Tesla? Or, did you replace it with an aftermarket item? In any event, the fact that you replaced a component that can change your speed certainly should be considered as the root cause of your issue.
If Tesla replaced your steering wheel, then you should open a service ticket for them to check it.
Reading speed limit signs
Years ago when I had my Roadster in the shop for service, I got a Model S loaner with the old Mobileye system. It had its shortcomings, but one thing that did impress me was its reading of speed signs — not quite flawless, but pretty darn close. Autopilot was also able to adjust its speed...
teslamotorsclub.com
I don't think it uses GPS for speed limits.
It absolutely does use map data for limits. When you make a right turn, or exit a freeway, the car adjusts the limit to the new street, even without a new limit sign.Reading speed limit signs
Years ago when I had my Roadster in the shop for service, I got a Model S loaner with the old Mobileye system. It had its shortcomings, but one thing that did impress me was its reading of speed signs — not quite flawless, but pretty darn close. Autopilot was also able to adjust its speed...
I don't think it uses GPS for speed limits.
clydeiii
Member
First and most important question: is it "randomly" or is actually randomly? Meaning, it seems random but there's actually a pattern, or truly random? To test for randomness, you must drive on the same road at the same time each day in the same traffic conditions and notice if the speed limit changes are the same each time or different. Once you have that info, report back please. Will help us diagnose.
Silicon Desert
Well-Known Member
yes it does. Actually, uses both GPS map data and the camera.
But for the OP, if it is extremely dangerous as listed in bold caps, don't let it do it "at least a dozen times" on your trip. I'm baffled why folks do that.
Silicon Desert
Well-Known Member
Good question. I can't say for sure. My car changes the speed from 25 to 45 as soon as I leave the neighborhood and drive on to the main street and there is no speed limit sign until about 1/2 mile further down the road, so it is using gps map data for that. Also when I come back home it does the opposite and changes from 45 to 25 before seeing any sign.
Everywhere else out on the freeway and other residential areas, it changes speed limit as soon as it sees the sign.
Silicon Desert
Well-Known Member
As far as I know, yes. Mine does the same thing and I have been hearing discussions about this out at the GF. That's not the only sign that it ignores and needs to process in future versions.
I had a similar occurance last night (clear weather, no traffic around me). On 3 lane interstate at 65mph, autopilot set speed dropped (no input from me) all the way down to 35mph. Unnerving.
+1 here. New Model 3, 110kph limit, and for the same stretch of highway (maybe 1-2km) if I try and set the cruise control (ACC, not auto-steer) to the speed limit after about a second it'll drop the CC limit to 80kph. Not fun in morning rush hour traffic...
I thought similar to previous posts, whereby the cameras may have picked up a rogue sign on an adjacent street, but the next time through that stretch I kept an eye on the speed limit on the display and it never wavered from 110kph.
Now I know it's there I check every now and then to see if it'll still glitch, but it worries me there may be other spots like this where you'll get pole-axed by someone behind you in a non-adaptive cruise control vehicle
I thought similar to previous posts, whereby the cameras may have picked up a rogue sign on an adjacent street, but the next time through that stretch I kept an eye on the speed limit on the display and it never wavered from 110kph.
Now I know it's there I check every now and then to see if it'll still glitch, but it worries me there may be other spots like this where you'll get pole-axed by someone behind you in a non-adaptive cruise control vehicle
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