LWR "Problems": Analysis and Solutions

Good morning, everyone.

I've been having a problem with my automatic headlight leveling system for a few days now.

First, the left side completely stopped working; the headlight moved downwards but didn't move back up.
I initially just accepted it like that (since I didn't have a laptop with me).

The headlights were slightly adjusted upwards by hand, and then I drove home.

No errors were found during the diagnostic scan.

After troubleshooting the error, I re-initialized the control parameters. However, I couldn't continue testing to see if it worked because I had to go to work.
So, I drove with one "fixed" headlight and one regulated headlight.

The following morning, both headlights were again in their normal position.
Okay, headlights turned off again.

Only one phenomenon is causing me some concern.
Als nur ein Scheinwerfer angesteuert wurde hat der andere permanent nachgeregelt bei jeder Bodenwelle hat der Scheinwerfer nachgestellt. But it's very extreme.

Since both sensors are working again, the issue is almost gone, but it still slightly reduces power when accelerating, then returns to normal operation. However, it doesn't do it as quickly as when only one sensor was malfunctioning.

My problem is that my car's low beam headlights never used to do that before.
It was configured during setup and that was it.
It seems like my automatic LWR (likely referring to a lighting system) has somehow become a dynamic one.

Can anyone explain this to me?
Should I be worried?
Or should I just be happy with my free LWR "upgrade"?

Hello everyone.

I think I've found the error.
The problem was with the cable to the diagnostic connector.
I accidentally pinched it between the dashboard bracket and the lower trim panel during assembly.
At the beginning, everything was still going well.
Now, my VAG-COM device stopped working.
"Short circuit to ground" on K1.

Okay, I removed the cover and that's when I saw the problem. A crushed cable and the insulation worn away due to vibrations. It was still attached to the metal bracket of the cover.
I removed it first, and then the VAG-COM started working again.

I first fixed the cable.
Of course, I disconnected the battery beforehand. That goes without saying.

Now I'm getting an error message like that.
"Signal interruption, cable to combination instrument."

The cable is working again. Could it be that the contact resistance is now too high due to the soldering?

Hello AWX-Driver,

I can't imagine that the welding point is the problem if it's been cleaned properly.

I can imagine that if you had a short circuit on the K1 line connected to the combination instrument, it could have caused the instrument cluster to fail.
! This is just a guess! A standard communication component can only provide a very small amount of current, in the mA to µA range.
If a short circuit occurs without any protective circuitry (current limiting/isolation), a standard IC is likely to be damaged.
But again, I don't know the circuit! So everything is just a guess, not based on knowledge!

Best regards, Christian.

As an electronics developer, I believe that Volkswagen would have certainly ensured that the diagnostic bus, which is connected to the diagnostic connector, is protected against short circuits to both operating voltage potentials.

I would check the wiring from the diagnostic connector to the instrument cluster; there might be a fault somewhere else in that circuit.

Best regards,
Sure, here's the translation:

"Guste" is a German word that means "gust" or "gust of wind." It can also be used to describe a sudden burst of something, such as laughter or anger.

Hello everyone.

I'll check the cable again this weekend.

The funny thing is, for example, I can see the data from the two axle sensors, so the connection seems to be working somehow in principle.
The actuator test is also working.

However, the attempt to relearn the rules failed because no data was received from that source.

I'll be in touch again!