MP4.2+6.0

I put together this thread on the practical "how to" for adjusting D4 LED headlights of the U.S./North America non-matrix types. It's easy. No different than the HIDs in approach. No bad things happen, no need for VCDS work, no big bucks car alignments or fancy headlight alignment machines, no electronic meltdowns, no dash error light show.

For background on "why," a few recent posts gave some context. See https://www.audiworld.com/forums/a8-...-beam-2899784/ and https://www.audiworld.com/forums/a8-...ature-2899675/ .

I decided to check things out for myself with my now 5,000 mile 2015 S8 against my favorite headlight adjusting wall. In the first 10 seconds I realized the pros from Neckarsulm pretty obviously did not dial these in with any precision. What I found was the driver's side headlight was aimed somewhat higher than the passenger side. That makes no sense from any conventional norms of headlight adjustment for left hand ("U.S.") drive, where the driver's side if anything is usually dialed down a bit. Passenger side also was aimed a bit to right. That is not unusual in my experience if you want to light up roadside edge. But the LED's are very strong at throwing an even and wide field, so forcing of the passenger side to right seems obsolete as a generalized approach. As originally adjusted, it didn't seem to be doing anything meaningful/of value to the right, but was reducing straight ahead value. Pictures follow below to try to illustrate these various points and observations. Sorry some did not focus as clearly as I thought on my phone, but still good enough to support most points.

Basics: a 6 mm very long allen wrench, a dark unobstructed wall, and a towel to cover one headlight at a time. I have a favorite dimly lit church school parking lot with a broad cinder block wall I always use. From pacing it, I was 75-80 feet from the wall in the pictures below. Anything from 50-100 feet probably can work similarly. The broad light cutoff you see across most of the wall is 12-15" off ground as a reference point for what I was seeing and doing. Also bring a flashlight or a phone with flashlight function. You need it to find the adjusting holes in the dark since headlight power is dimming your eyes' night vision. There are also two rubber plugs on top of the outer adjusters. Take those off in advance and do NOT lose them. I bagged for safekeeping. Cannot be bought as replacement parts.

First pic shows the adjustment points of drivers side. The inner hole where I stuck the T allen wrench is for the up-down adjustment IIRC--the one you are most likely to dial in more. The outer hole close to the fender on each side is the one with the rubber plug/cap (in plastic bag) to safeguard. It deals with side to side adjustment if I remember right. Again, 6mm allen, though you can also see inside at least the one close to the fender also has a Phillips head molded into it. Have your tool figured out in advance. The inner one needs a long reach tool of some sort.

Next, I positioned car at distance form my favorite wall. I covered each headlight in turn to see where my starting point was. Hood open, and just loosely throw a beach towel over one or the other. I also sighted along side of car from the rear corners to see if it is projected straight ahead or favored one side.

What I found is either LED light has great overall projection.The beams of each are very well distributed and strong, with none of the common unintended "hot spots" you see with lots of headlights, including on big bucks Euro rides with mediocre real lighting. Right side does not aim upward like I have seen with prior gen Audis and especially any "Euro" style units. Each one also projects two strong beams virtually straight ahead that you see with two slight spikes in the visual field. Those would light up the lane straight in front and further down the road than otherwise with a conventional bulb cut off set up. This is when i saw passenger side was clearly somewhat lower and somewhat to right. You will have to trust me on the slightly pointed to right observation. It can't be captured in an easy picture, but was obvious in the left-right comparo on site with the towel. I ended up dialing up drivers side very slightly (maybe three vertical inches on the distant wall) and then matching passenger side to it. I also walked down field from the car like I always do to crouch down and look toward headlights like if I were a pedestrian or other driver. Thus make sure they are not obviously glaring even at a low passenger car seating position, putting aside the plethora of high up SUV's out there with the incessant fool fog lights on 24/7. Of course no glare standing up, but also crouching down to where eye level is only 3 feet or so. Lights should be quite bright looking directly at them, but not seem as though they are on "high beam" as a pedestrian.

Pictures below are:

1. Basic pointer to adjustment screws.
2. Starting points of both headlights together (all pics were with hood open, standing just to left of base of hood in front of door on drivers side).
3. Driver's headlight only, pre-adjust.
4. Passenger headlight only, pre-adjust. Not aimed as high as driver's side when you look at either the two higher points or the general cut off. Subtle, but at distance it matters.
5. Post adjustment, both together, aimed as explained in text above.

Finally, I drove it another hour post-adjustment last night, both city streets and highway run to meet someone. All good. Better reach, no negatives. Pulling up to cars (non SUV's) behind, lights hit no higher than about top of rear license plate either following well behind or pulling up to stop. Thus not glaring at other drivers or their rear mirrors.

And yes, no dash warning/error lights or any issues, during or after adjustment, night or later day. The bad weather function still throws more broadly like before (akin to fog lights). It took me longer to type this up than to do it; 15-20 minutes at the dark wall site.

Ravill

Great little write up man thanks!!

Silver_Solid

Thanks for the pics and write up. I'm considering trying this for my LED matrix light where i also felt passenger side was slightly lower than drivers side (very odd indeed.)

Silver_Solid

Just used the guide to adjust my headlights, and the output is just amazing! no more hotspots and the output is evenly spread. Many thanks OP as i would have never thought it was so easy to adjust a headlight dubbed "Matrix" lighting.

lauwersp

Really appreciate the write up. The VW Phaeton forum at VWVortex.com has a lot of knowledgable members who do write ups like this and it's really helpful... even just in understanding how something should work regardless of whether you have any desire to actually work on your car or not.