Car lowering and headlight leveling

[SteveYem]

Two weekends ago I had coilovers installed on my 2015 S4. Ride height is currently 25.5" fender-to-ground both front and rear, versus the stock ride height which had the rear end ~1/4" higher than the front. As I have been driving around at night during the past week, I have noticed that my headlights appear to be aimed too low, such that I have ~20 feet visibility at night when the low beams are on. I presume the incorrect aiming was caused by lowering the car. When I turn on the car the headlights turn on and do their normal low-to-high sweep, so the projector leveling motors are functional.

I did some research on the issue and found some discussions on various Audi and VW forums. What I read is that lowering the rear of the car compresses the rear suspension to beyond its OEM condition, and therefore the headlight auto-level sensor which connects to the rear driver side control arm detects the compressed condition and causes the headlight projectors to aim lower....just like if the back of the car was weighed down causing the front end to pitch up.

Supposedly the fix is to park on a level surface and access the Headlight Range control module [55] in VCDS where you can calibrate the headlights. If I understood the tutorial correctly, you go into this module and it puts the headlights in calibration mode, then you manually adjust the low beam projector position using the white adjusting screws on the headlight housings, then in VCDS you tell the car to learn the current position as the default "neutral" position.

Here's the problem: when I went into VCDS and selected the Headlight Range [55] module, it chugged on it for 20 seconds and then returned an error "Cannot Connect to Control Module" (or something along those lines). I tried it ~10 times and received the same error each time. I also tried to access the control modules for the individual left and right headlights and received the same error for both. I verified that VCDS was working properly by accessing some other control modules successfully.

Since I was unable to get into the headlight range control module, I only manually adjusted the projectors using the white screws on the headlights. The low beam range seems to have improved accordingly, even though I did not recalibrate them via VCDS. The discussions I read on the topic implied that if the projectors are adjusted manually but the new position is not "learned" by the car via VCDS then the car would automatically default back to the original position when restarted, but that doesn't seem to be the case with mine.

Worrying that the auto-level sensor(s) could have been damaged during the coilover install, I scanned the car for trouble codes via VCDS but it found no codes. I also looked underneath the car and verified that the sensor on the rear driver side was indeed connected to the lower control arm of the suspension.

So my questions are:
1) Have any of you run into this issue after installing coilovers or lowering springs?
2) Is the error message "Cannot connect to control module"(paraphrasing) typically due to a hardware malfunction, in this case faulty auto-level sensor(s)?

[GalaxyS4]

I dont have vag-com but all i did was turn the white screws on top and this fixed my headlight issue. I remember reading in an old thread that this is all that was required. No need to change anything else. I'm pretty sure your OK. Cant help you with the codes though.

[mojangles69]

I've noticed the same thing with my vehicle after having new coilovers installed and the car lowered. Will be trying the "white screw" method first. Did that on my A4 and it worked fine. Hopefully it'll work this go around with the S4!

[Pilfer]

that's weird, i've been lowered first on springs and now on coilovers for over a year and never noticed a difference.

[Maitre Absolut]

I dont have vag-com but all i did was turn the white screws on top and this fixed my headlight issue. I remember reading in an old thread that this is all that was required. No need to change anything else. I'm pretty sure your OK. Cant help you with the codes though.

Link to procedure? I have same problem as SteveYem and also had it on my previous audi, never fixed it

[SteveYem]

I dont have vag-com but all i did was turn the white screws on top and this fixed my headlight issue. I remember reading in an old thread that this is all that was required. No need to change anything else. I'm pretty sure your OK. Cant help you with the codes though.

Thanks for the feedback. I agree that adjusting the beam pattern up using the white screws seems to have worked without the use of VCDS, although that's contrary to some discussions I read online.

I've noticed the same thing with my vehicle after having new coilovers installed and the car lowered. Will be trying the "white screw" method first. Did that on my A4 and it worked fine. Hopefully it'll work this go around with the S4!

Please report back with your results! FWIW, I made a mark with a pencil on the end of the white plastic adjustment screw and recorded how many turns (and in which direction) I went from the factory setting, just to have a reference point.

that's weird, i've been lowered first on springs and now on coilovers for over a year and never noticed a difference.

How much did your static ride height change from stock to springs, and then from springs to coilovers? I wonder if the car can somehow adapt and keep the beam pattern correct if the ride height changes are more gradual? (I don't really see how or why, just trying to explore all possibilities).

[SteveYem]

Link to procedure? I have same problem as SteveYem and also had it on my previous audi, never fixed it

The headlight projector angle can be changed up and down by manipulating the adjustment screws built into the back of the headlight assemblies. Pop your hood and look at the upward facing surface of the headlight housing, toward the rear, and you will see a white plastic knob/screw on each housing. You can fit a medium size philips head screwdriver into the adjustment screw and turn it Clockwise to raise the beam pattern, Counter-Clockwise to lower it.

There is a "correct" procedure for achieving factory headlight range settings which entails having a perfectly flat surface to park the car on, and a blank white wall 40 feet in front of the car as well as a target that gets affixed to the wall at a certain elevation. I didn't really have access to any of those things so I decided I would do it by trial and error.....I made a mark at the 12 oclock position of the adjustment screw (directly toward the rear of the car when they were in their factory positions) and turned each one a full revolution in the clockwise (raising) direction. I then drove the car at night and took note of whether anyone was flashing their high beams at me due to being blinded by my headlights. I received no negative feedback, so I am assuming they are OK. Clearly not a very scientific approach, but I figure as long as I can see and oncoming drivers don't appear to be offended, then that's good enough for me.

Make sure to raise and lower both sides the same amount. I'm sure you've noticed that the passenger side is set higher than the driver side and it is important to maintain that relationship.

[AudBoost]

Link to procedure? I have same problem as SteveYem and also had it on my previous audi, never fixed it

Here's the link to the previous thread: http://www.audizine.com/forum/showth...the-auto-level

[SteveYem]

Here's the link to the previous thread: http://www.audizine.com/forum/showth...the-auto-level

Thanks for the link. I searched but unfortunately did not find that before posting this one.

Seems that the consensus is that adaptation via VCDS is not necessary because the car will retain the manually adjusted setting as its "home" position. Someone also mentioned in that thread that the auto-leveling function remained intact. This point I'm not so sure about. On my B8 (which was lowered on H&R OE) as I was driving on back roads with undulations I could see the beam pattern adjusting up and down as the car went down and up (respectively). Last night when driving, after I had manually adjusted the beams upward by one full turn on the adjustment screw, it did not seem like the beam pattern was shifting as the road incline varied. Meanwhile I confirmed visually that the lights swept down-up when I turned the car on, so I know the motors are at least functional.

[sturte30]

I was the starter of the old thread.... I tried the white screws and it worked fine. No issues.

[SteveYem]

I was the starter of the old thread.... I tried the white screws and it worked fine. No issues.

Thanks for chiming in. Can you confirm that they still actively auto-level while you are driving, i.e. you can actually notice them adjusting up/down while on an undulating road surface?

[sturte30]

I don't drive on many undulating roads so I can speak to that. However, they do cycle up and down as normal on start-up.

[VADERS4]

Yep! White screws work perfectly! Just turn them a little at a time and adjust them against a level surface like your garage door (if driveway is level!LOL!).

[SteveYem]

Yep! White screws work perfectly! Just turn them a little at a time and adjust them against a level surface like your garage door (if driveway is level!LOL!).

If the car is not on level ground when adjusting the white screws, does the computer interpret the new position setting as "level" and then point the lights too high when you get onto flat ground?

[Race Shooter]

Does it matter if you do the adjustment with the car and lights on or having the car shut off? How have other successfully done it?

[SteveYem]

Does it matter if you do the adjustment with the car and lights on or having the car shut off? How have other successfully done it?

My manual adjustment seems to have held. I had the car level (or as close to level as I could get it) and the lights turned on when I did the adjustment.

[wago]

I'd also check the level sensors - make sure they're properly hooked up to the A-arms on the front and rear suspension. I had this exact problem on a lowered mk5 R32 and it turned out that the rear position sensor had been incorrectly reinstalled (it's an articulating arm that can be installed backwards) causing the headlights to stay in the fully-down position. Simple fix to jack the car up and reattach the sensor correctly. I haven't looked at the B8 platform headlight sensor, but suspect it's similar. Anyone have hands on experience with this on a B8?

[levigarrett]

that's weird, i've been lowered first on springs and now on coilovers for over a year and never noticed a difference.

Same, I don't see a significant difference.