Ml320 is complaining about almost all rear lights
 

I've had this thing for a little over a year and no major problems other than turbo issues. I've had the car sitting in the driveway not running due to a another turbo issue for the last 6 weeks. The battery did get really low but didn't need jumped when I started it. After getting it back on the road I noticed that it was complaining about the 3rd brake, right reverse and left turn signal. Hoped it just needed ran to charge the battery. No luck, after turning on the light switch I realized that the only lights it didn't complain about was 1 turn signal, 1 reverse and 1 brake. All others got warnings. The SAM was just replaced right before I got it, no signs of water in the area.

Where do I begin on troubleshooting this? I'm assuming the module is actually partially working if it's reporting back. Anything that can be reset?

I hooked up the scanner and can communicate to the module and see all the codes. Ran through a bunch of tests and it says the actuators are functioning properly but the lights aren't working except for the few.

I took it to a local euro garage and they are saying its the rear SAM. I took it out and definitely had some corrosion. I cleaned it up with some electronic cleaner and alcohol. going to try it tomorrow to see what happens. Weird that the power seats, rear auto hatch, sun roof etc works fine just the rear lights. A few of the lights actually worked on the way to the shop when they didn't before.

You may have water entering due to faulty tail light seals. Make sure you water test before you replace the SAM or you'll be doing it again...........