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Autopilot only works if I leave the headlights on!!!

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timk225

Active Member
Mar 24, 2016
2,140
2,486
Pittsburgh
This has been tested and confirmed. My base AP in my 3 only works if I leave the headlights on in a certain driving situation.

Lemme 'splain. Your first question may be "Whaddaya mean IF you leave the headlights on? They are on by default!". Not in my 3 they aren't. For nearly 4 years, I get in the car, enter the LOCK CODE (from the start of the Transporter 2 movie, that sounds cooler than "pin to drive"), and I manually TURN THE HEADLIGHTS OFF. I'm a man of principle and have been driving for 30+ years, I don't need some Tesla engineer to decide when my headlights should be on! I don't care if I'm only driving a mile, I manually turn the headlights off!!!

So anyway, I drive a 20 mile stretch of highway to go to work, either north or south on this road. Driving north is no problem, the AP works well nearly all the time.

But coming south on this same road, with similar quality paint lines, AP is tripping off constantly, if it will even go on at all. I took my 3 into the service center, and they said the AP is working fine. Sometimes AP will work when driving south on this road, but mostly it does not.

A few days ago, I had to work an odd shift for 3 days that had me coming home late at night in the dark. So my headlights were on. And the AP worked fine when driving south, the whole 20 miles.

So today, driving home at 8 am, I ran a little test. I left the headlights on. And what do you know, AP was working fine. About 6 times, I turned the headlights off, and within 10 seconds, I am getting the alarm and the bright red steering wheel on the screen, and the AP trips off. It'll maintain speed, but it won't steer.

Then I turned the headlights back on, and reactivated AP, and it came back on and worked fine.... until I turned the headlights off again. Over and over for 20 miles.

My guess is the headlights reflect off the paint lines just a little bit extra, enough to keep AP happy. This never used to be an issue in nearly 4 years and 81,000 miles of driving. I guess some recent update made the AP a little more picky as to the quality of road paint lines that it needs.

Anyone else notice this?
 
This has been tested and confirmed. My base AP in my 3 only works if I leave the headlights on in a certain driving situation.

Lemme 'splain. Your first question may be "Whaddaya mean IF you leave the headlights on? They are on by default!". Not in my 3 they aren't. For nearly 4 years, I get in the car, enter the LOCK CODE (from the start of the Transporter 2 movie, that sounds cooler than "pin to drive"), and I manually TURN THE HEADLIGHTS OFF. I'm a man of principle and have been driving for 30+ years, I don't need some Tesla engineer to decide when my headlights should be on! I don't care if I'm only driving a mile, I manually turn the headlights off!!!

So anyway, I drive a 20 mile stretch of highway to go to work, either north or south on this road. Driving north is no problem, the AP works well nearly all the time.



My guess is the headlights reflect off the paint lines just a little bit extra, enough to keep AP happy. This never used to be an issue in nearly 4 years and 81,000 miles of driving. I guess some recent update made the AP a little more picky as to the quality of road paint lines that it needs.

Anyone else notice this?
That is correct. Waning hours of the day and early morning they must be on or one cannot engage autopilot. Just like the lights coming on when wipers are on. Helps idiot proof the car. It's not just your car.
 
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Lemme 'splain. Your first question may be "Whaddaya mean IF you leave the headlights on? They are on by default!". Not in my 3 they aren't. For nearly 4 years, I get in the car, enter the LOCK CODE (from the start of the Transporter 2 movie, that sounds cooler than "pin to drive"), and I manually TURN THE HEADLIGHTS OFF. I'm a man of principle and have been driving for 30+ years, I don't need some Tesla engineer to decide when my headlights should be on! I don't care if I'm only driving a mile, I manually turn the headlights off!!!
Unfortunately, too many people drive around at dusk and dawn because they don't think they need headlights; they can see perfectly well. But others have trouble seeing them and that's the problem. Your 8am drive in Pittsburgh area may still be too much twilight since sun rises around 6:50am. People are penny wise and pound foolish is my guess. The price of headlight replacement is worth far more than an accident or a life. JMHO. BTW, your wipers must be in AUTO because I don't think AP will engage without that setting as well. At least it won't in my Y.
 
Arnold Schwarzenegger can drive at night without headlights and even waring dark sunglasses.
Screen Shot 2022-03-08 at 12.27.56 PM.png
 
No, they will turn on even in mid-day if it is a cloudy day and the front of the car is facing away from the sun, or if the car is in enough shade, I've seen it many times.

They only turn on at night anyway, so what's the issue with leaving them in auto? Do you like driving around in the dark with your lights off? If so, that's incredibly unsafe...
No, I turn them on when needed, I just don't like the auto-headlight idea in general. I've been turning my headlights off and on manually for 30+ years.

I did a better job in diagnosing this phenomenon than Tesla could!
Well, yes. It is what it is. Teslas being designed in California have numerous deficiencies in a Pittsburgh winter, so why do we think they got the headlights 100% right? Tesla need to have some sort of heat ducting that blows warm air on the outside of the side windows inside the door.

Unfortunately, too many people drive around at dusk and dawn because they don't think they need headlights; they can see perfectly well. But others have trouble seeing them and that's the problem. Your 8am drive in Pittsburgh area may still be too much twilight since sun rises around 6:50am. People are penny wise and pound foolish is my guess. The price of headlight replacement is worth far more than an accident or a life. JMHO. BTW, your wipers must be in AUTO because I don't think AP will engage without that setting as well. At least it won't in my Y.
Could be, at 8am the sun is above the horizon but still at a low angle. This takes place out in the middle of nowhere, where the surrounding terrain is fairly flat, for Pittsburgh.

Whatever the reason function or safety....why do you want to turn off your lights anyway?
Because 'MERICA !!! :)
 
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No, they will turn on even in mid-day if it is a cloudy day and the front of the car is facing away from the sun, or if the car is in enough shade, I've seen it many times.


No, I turn them on when needed, I just don't like the auto-headlight idea in general. I've been turning my headlights off and on manually for 30+ years.


Well, yes. It is what it is. Teslas being designed in California have numerous deficiencies in a Pittsburgh winter, so why do we think they got the headlights 100% right? Tesla need to have some sort of heat ducting that blows warm air on the outside of the side windows inside the door.


Could be, at 8am the sun is above the horizon but still at a low angle. This takes place out in the middle of nowhere, where the surrounding terrain is fairly flat, for Pittsburgh.


Because 'MERICA !!! :)
Can someone insert the “old man yells at cloud” meme?
 
This has been tested and confirmed. My base AP in my 3 only works if I leave the headlights on in a certain driving situation.

Lemme 'splain. Your first question may be "Whaddaya mean IF you leave the headlights on? They are on by default!". Not in my 3 they aren't. For nearly 4 years, I get in the car, enter the LOCK CODE (from the start of the Transporter 2 movie, that sounds cooler than "pin to drive"), and I manually TURN THE HEADLIGHTS OFF. I'm a man of principle and have been driving for 30+ years, I don't need some Tesla engineer to decide when my headlights should be on! I don't care if I'm only driving a mile, I manually turn the headlights off!!!

So anyway, I drive a 20 mile stretch of highway to go to work, either north or south on this road. Driving north is no problem, the AP works well nearly all the time.

But coming south on this same road, with similar quality paint lines, AP is tripping off constantly, if it will even go on at all. I took my 3 into the service center, and they said the AP is working fine. Sometimes AP will work when driving south on this road, but mostly it does not.

A few days ago, I had to work an odd shift for 3 days that had me coming home late at night in the dark. So my headlights were on. And the AP worked fine when driving south, the whole 20 miles.

So today, driving home at 8 am, I ran a little test. I left the headlights on. And what do you know, AP was working fine. About 6 times, I turned the headlights off, and within 10 seconds, I am getting the alarm and the bright red steering wheel on the screen, and the AP trips off. It'll maintain speed, but it won't steer.

Then I turned the headlights back on, and reactivated AP, and it came back on and worked fine.... until I turned the headlights off again. Over and over for 20 miles.

My guess is the headlights reflect off the paint lines just a little bit extra, enough to keep AP happy. This never used to be an issue in nearly 4 years and 81,000 miles of driving. I guess some recent update made the AP a little more picky as to the quality of road paint lines that it needs.

Anyone else notice this?
God these forums are getting ridiculous. Leave your running lights on. Let your car control the lights and move on.

Assuming it has anything to do with road lines during the day is conjecture, and absurd conjecture at that.
 
Um, yeah, the vision-based AP needs to see at night. I do disagree with overly-aggressive use of highbeams, but year it needs access to headlights so it can reliably see.

My 3 is an early April '18 build with the radar AP, not the newer vision-only AP.

We had a very overcast cloudy day this morning on my way home at 8am, so no real glare from the sun or anything. Yet the AP behaved the same. Turn off the headlights and the AP freaks out. But only when heading south on this 20 mile stretch of highway, when going north it is fine with no headlights.
 
My 3 is an early April '18 build with the radar AP, not the newer vision-only AP.

We had a very overcast cloudy day this morning on my way home at 8am, so no real glare from the sun or anything. Yet the AP behaved the same. Turn off the headlights and the AP freaks out. But only when heading south on this 20 mile stretch of highway, when going north it is fine with no headlights.
It’s a Tesla vision thing. If your order was before the change, you signed an agreement stating there were changes in functionality. One of these changes is auto headlights and auto high beams are required. You can read about it in the manual. If you don’t like this, sell your model Y and buy one built with Radar.

I don’t like auto high beams and how much they blind oncoming drivers so I will use autopilot less at night.

Also, it’s daylight and the lights don’t change what you see. Why do you care if they are on or not?
 
I haven't read about something like this on here so just a short story on my experience today.

I frequently learn something new whenever I take a drive. I was driving on a well marked highway before dusk. There was plenty of daylight and I noticed that my headlights were on so I turned them off. A few seconds later I tried to engage Autopilot but got a message that it was temporarily unavailable. A minute later I entered another highway and tried Autopilot again and got the same message. I thought that perhaps this was in response to turning off the headlights so set the headlights to auto. I tried Autopilot again and this time it worked. I don't know for sure if this was due to my actions but I thought it was interesting if it was,