Car model and year: 2008 Benz ML350 4Matic

Symptom: When starting the car and the headlights go through their up, down and side to side check, my driver-side headlight doesn't move. It remains in-place.

Solution:

There is no guesswork when it comes to Xenon as every everything is extremely expensive.
The codes must be read in the left Xenon control module.

You will need a scanner, not just a code reader , able to read all modules, like: Autel Scanner MD802

Or a Foxwell NT530, it will pull the codes.

For if I can replace with two halogen headlamps and it will not throw any codes, It will be a nightmare doing it as the wiring and sockets are entirely different.

Credits to @ Maj. Dundee (mbworld.org forum)

www.obdexpress.co.uk