Prime high beams issue

Not sure about setting sensitivity, but wouldn’t it be easier to just reach down to the lower left button bank and click off the auto high beams instead of holding the stalk?


iPad ?

 

Turn off the auto high beams. It’s a button under the left stalk. Not the most intelligent of features on the car.

 

the auto-high beams seem to turn themselves off when speed drops below 25mph. It's really damn annoying. I *understand* that the system probably doesn't work well at those speeds (since it cant detect the difference between two static lights and oncoming headlights so they probably disable it from blinding drivers across from you at an intersection. But I have a 270 switchback on the way to my house in the middle of farm country with no intersections and no one anywhere around me, and walla, just when you really WANT to have lots of light, the damn things switch to low beam, then either I have to use the "flash-to-pass" on the stalk or reach down and turn off the auto feature. (whose button is usually obscured by the steering wheel which makes it more fun to find).

The system also wants to blind cars in front of me going the same direction. It's usually pretty good about not blinding on-coming cars but preceding cars it just blinds away at.

 

I agree, and regard such "gewgaw" features as auto-dimming headlights/rear-view mirrors, auto wipers, in the same way as I might regard an automatic arse-wiping device in a toilet. As mentioned elsewhere, I think we're living in the Age of Entitlement, "…arms that can only lift a spoon" (anyone else remember that one?)

 

If you need high beams at a speed below 25MPH, you're doing something wrong.

 

With a nearby route I travel, 30km limit, twisty treelined road, pitch black, I need 'em.

 

I complained to Toyota Corporate Headquarter about incidences of high beam shutting off without any oncoming car or bright light ahead and the high bean not being available for a while after those auto off. They simply said, it is the normal operation of the "auto high-beam". The end of story. I have turned off my AUTO high-beam after that. Manual turning on and off of high-beam when and where needed works just fine for me.

 

My first automobile was a 1956 Cadillac and it had an "electric eye" Autronic automatic headlight dimmer. In those days, it was just a photocell mounted in a housing on the dashboard and aimed out through the windshield to detect oncoming lights. It would only work on dark rural roads because it could not distinguish between oncoming headlights and ordinary street lights.



The system used in the Prime is much more intelligent. Not only does it differentiate oncoming headlights from other miscellaneous street-scape lighting, it also does a pretty good job of recognizing tail-lights of cars for courtesy dimming. I believe this is because the current technology uses digital image processing and not just a simple photocell.

You can read more about the early automatic headlight dimming technology here: Autronic Eye - General Motors Twilight Sentinel | Hagerty Articles

 

My folks 58 Volks:

 

When I'm making a right turn into my neighborhood there are trees and parked cars and often people walking around or getting in or out of their cars. There are no street lights, so it's much darker than the main road. The low beams don't throw enough light to the side and up to really illuminate everything. Adaptive headlights that move when you turn the wheel, or maybe even the thing Subaru does with steering responsive fog lights, would be fine, but the Prime doesn't do any of that (and mine doesn't have fog lights). So the high beams are the next best thing.

The headlights are nice, but they don't always illuminate quite enough above the road surface to quickly identify people or bikes that don't have anything reflective. In addition to the really bright center square, the high beams also turn on more light above the road surface.

 

Yep, I found that out when I turned onto the road we live on coming off a 50 MPH road. Took a couple of times before I figured out why the high beams went off then came back on.

Um, no we are driving on country roads without any streetlights. I'd rather be able to see the deer on the side of the road ready to run out in front of me thank you very much.

That round foot button for high beams was very common. Click on, click off. I don't know when they moved it to a stalk on the column.

 

That left foot dimming switch was pretty much standard on cars prior to the introduction of the multi-function stalk in the 1970s. My late mother, who learned to drive on a manual shift car in the 1940s, later drove an automatic transmission vehicle and complained when the dimmer switch was removed from the floor: "First they take away the clutch pedal -- and now the headlight dimmer. What am I supposed to do with my left foot?"

 

Interestingly, the Insurance Institute for Highway Safety ("IIHS") originally rated the Prime's headlights as "poor." Apparently, Toyota made a design change in August of 2017 which resulted in the IIHS rating being raised to "acceptable" -- a mid-level rank which is still not up to IIHS's score of "good."

"Toyota improved the Prius’s headlights for vehicles built after August [2017], so the safety rating for post-August Prius models improves from Poor to Acceptable. This affects how well the headlights illuminate the road and reduce glare for oncoming drivers. The Prius headlights also get extra credit for high-beam assist, which automatically switches between low and high beams depending on the presence of other vehicles. This is an important safety feature because research shows that drivers don’t switch to high beams as often as they could.”

– Russ Rader, senior vice president of communications
at the Insurance Institute for Highway Safety
​

source: What the experts say about the 2017 Toyota Prius Prime | Boston.com​

I do not know if Toyota did anything to retrofit early 2017 Primes. Possibly someone could check to see if there was a service bulletin issued concerning the headlights.

I purchased my Prime in August of 2017, so I suspect that it pre-dates the improved headlights. However, doing mostly urban driving, I have not noticed any particular problem. (Of course, poster "m8547" has a 2018 model, so this is not particularly relevant to him.)

For an explanation of how IIHS evaluates headlights, see this article:
Headlights improve, but base models leave drivers in the dark

 

In retesting. I have the base 2017 and always notice how low the driver side is. Very difficult to see anything other than what it immediately in front of you. Makes it a bit precarious driving on unfamiliar roads at night.

 

These are adjustable (pages 637 and 638 of the 2018 manual). Put a Phillips screwdriver into the slot above the adjuster, and the prongs of the Phillips will engage the drive screw. The stamped marks on the plastic trim panel show which was to go for up/down and L/R adjustment.

 

The headlights were one of the things that sold me on the Prime, but also one of the biggest disappointments after I bought it and spent some time with it.

Interestingly consumer reports has a totally different headlight rating system that doesn't correlate with the iihs ratings. But I don't subscribe and I can't remember what they gave the Prime.

As I mentioned before, slightly more light above the cutoff would be helpful, but I don't know if more is allowable without blinding oncoming traffic. Adjusting them slightly up could help a little, but it will also increase glare in a lot of cases. Auto leveling would really be the best solution.

In another thread I read the Prime gets adaptive headlights in some markets, where the high beams could be on but electronically make a dark spot where a nearby car is, by turning off just some of the LED emitters. They could use the same technology for auto leveling with no moving parts.

Another disappointment is how slowly the automatic high beams react. I end up turning them off first at least half the time. Around here it's rare to be able to use the high beams at all, but if they had nearly instant reaction time I might get to use them at least a little.