Automatic High Beams Not Functioning?

Now that it is cold again I am experiencing this issue again.

the auto high beam operation is 100% perfect when warm, and operates as my last post describes when cold. It worked for a good 6 months or so but is acting up again.

Today I was so fed up I parked the car and got out to look at it. I noticed that the front camera was obscured by condensation, on the lens and in the little triangle between the windshield and camera housing. I believe every time it acts up there is condensation in the housing. The front defrost can not remove this and there is no other condensation on the windshield.

I am looking into how to remove the housing so I can clean there and maybe apply some anti condensation product.

 

OK I would like to report that I was able to figure out how to remove the housing for the camera and the camera itself. Once I removed this I noticed that there was a very thin clear and sticky slightly cloudy liquid covering the windshield in that area that I believe is attracting condensation.

It just felt sticky when I touched there. It was difficult to remove but I did remove it. I suspect it may be related to offgassing and may have been on the entire windshield but I was able to clean that slowly over time. It would also explain why I noticed the system was getting worse over time.

Once I cleaned that all the way off I reassembled everything and I can report that my automatic highbeams did work perfectly today, just as well as it does in warm weather. The feature did not shut off the entire drive.

Since there are no other reports on this I figured I would include some quick instructions on how to do this, with the obvious caveat that I am not responsible for anything you may do.

first I would like to mention that Toyota says you need to re-calibrate the camera anytime you remove the camera or the windshield. However once I made it to the camera I quickly saw that the camera module is free to rotate around itself on every axis by at least 10°. It certainly moves around from just normal driving and the tiniest bump can move it slightly. I did not re-calibrate and confirmed that all of my features were still working properly. You will have to remove the entire housing and the camera to do this.

first you have to remove the small piece in the center above the mirror. There are two clips one on the left and one on the right at the base near the headliner that push inward(left/right), then two prongs on the opposite side that push towards the mirror.

After you remove that piece you will see that the main housing has a clip that you need to squeeze on both the left and the right. You will need to squeeze both at the same time and push the housing forward towards the windshield.

after that you will see the camera module and see that is fairly loosely installed and is also installed into a plastic cage. There are two tabs that you have to press in to remove the plastic cage. The camera will remain floating in its mount on two tabs per side, to remove that you will need to pull back on the camera. I left the camera plugged in and just hanging down behind the mirror.

After that there is a triangular plastic clip, the one that you can see from outside that is covered in felt. There are two clips at the base of this that you can press in to remove.

after this you will be staring right at the triangle that is the visible portion of the windshield inside the housing. When I touched this it was very sticky and there was obviously some substance that evaporated and settled here. I cleaned it very well with a microfiber cloth and reassembled everything.

The difference seems to be dramatic. Just yesterday/this morning the feature was disabled for more than 50% of the drive, and now it worked 100%.

 

I've experienced the Auto High Beams function (2019 Prius XLE) not functioning for sometimes up to five minutes of driving. Once the system "warms up" it works fine.

My 2018 Subaru Legacy does the same thing.

This may be endemic with such systems.

I remember that the auto high beams worked fine in my aunt's 1955 Oldsmobile Super 88 - in the days before transistors and fancy electronics.

 

I don't use it because I don't like the Auto high beam on the Prius, it's not quick enough. I invariably see cars coming the in other direction way before the auto does and as a courtesy, manually switch to low beam before they appear, by the time the auto high beam switches the poor driver on the other side has been blinded for about a second. Also after the car on the other side has passed, I'm in darkness for about a second before the auto switches, ok on a straight road but manually I would switch instantly.
The foot operated high/dip beam switch on my 1968 Morris Minor does it for me.

 

As I was reading though this thread (just found it), I was thinking, I don't even like the auto high beam. It's way too slow. And then I finally come to your comment where you say just what I was thinking. Great minds, eh!?

But I wonder if @liquidtenmillion's procedure would help with that. At least a little bit. I'm sure it would never be as quick as an attentive driver.

 

That's the key - on a straight road, which we've got plenty of, it's great. But you're right, other places, do it by hand.

Photo of your Morris?

 

If I may add, the road must be straight and flat. My usual drive includes straight but with the up and down stretch of a road. When a car ahead of me is in the "valley", it effectively disappears from the site, and quickly reappear upon getting on the "hill" segment. The auto high beam just can not react quick enough for that situation.

 

This problem has been reported numerous types on Toyota and Lexus forums. Others have found that cleaning the camera lens and the windshield in front of it solves the problem. Most have had their car dealer do the cleaning since camera realignment can be required.

It appears that the problem is caused by a design flaw that allows film from off gassing to build up over time and not easily be removed.

This problem does not occur on the older auto high beam system which has its camera suspended in front of the interior rear view mirror. On that system, which we have on our 2014 Sienna, the camera lens and the windshield in front of it is easily cleaned without disturbing the camera.

How quickly film builds up on the camera lens and windshield in front of it may depend on factors such as climate. Perhaps cleaning the lens and windshield in front of it should be done routinely - perhaps annually.

 

I've just cleaned windshield in front of the camera by using the procedure described in post #42 . Everything went smooth and it took me only 5 min to remove everything. All functions are working fine after putting everything back together ( no recalibration ).

 

Thank you for posting that procedure.

Our auto highbeam feature has been on the blink for over six months, But it feels like such a minor feature that I have never mentioned it to the mechanic. At $100/hour he can focus on the important things.

I only found this thread today.

That area of the windshield looked and felt clean when I finally gained access to it, I went ahead and cleaned it with cotton swabs and alcohol.

Tonight I plan to test to see if it works

 

This is a pretty old thread. Sometime after it went dormant, I cleaned the glass in front of the camera. Here's how it's done.

 

My parents ‘58 VW was the same. Good idea; universally dropped now I think.