Hey everyone, I've got a bit of a head-scratcher here and was hoping to tap into the collective wisdom:

I've got a 2012 S212 wagon that's been exhibiting some weird behaviors lately.

• Often while driving, I will get a message on the center cluster that my car is attempting to place an SOS call. It displays a message in red on the dashboard, and I have to cancel it by hitting the 'end call' button on the steering wheel.
• When parking the car and exiting, the rear hatch will either unlatch itself or fully open. A couple of times, when I have closed it, it will simply open up again. As far as I know, it does not unlatch itself while driving, only when putting the car in park and opening the door.

Both of these issues started at the same time, and only happen periodically. I can go days without either thing happening, and then suddenly it will happen multiple times during one driving session. There seems to be no rhyme or reason for when they happen (the SOS calls aren't triggered by when I step on the brake, or accelerate heavily, for example) but if you were to press me I MIGHT say they are more likely to happen after it rains heavily. Additionally, I haven't seen anyone else with these two specific problems, and I have looked extensively.

I have some suspicions including damaged wiring harnesses at the rear hatch hinges, or a faulty auxiliary battery (but I haven't seen a faulty aux battery message). I just wanted to check in here before I committed to tearing things apart and chasing hunches.
Thanks for any help you guys can provide!

I think you have all the conditions gathered to cause a rain issue on CAN-B.

Now you just need to find out where this is taking place: either footwell or trunk area Both spaces can get flooded...

Use a good scanner to retrieve active fault descriptions and reset.

Coincidentally you want to preserve your batteries from high-drain with a float charger.

Check sunroof drains to make sure you're not getting water intrusion that runs down the A pillar to the passenger or driver footwell area under the carpet.

I would check the batteries first and as suggested checking the codes should be able to shed some light as well
Keep us updated

Thanks for chiming in, guys! Man, I'm really hoping this isn't a water ingress issue, but I'll need to dig deeper to be sure. I've had sunroof drain issues on previous cars, and it's always such a pain to address. Short of going whole-hog on a BenzNinja setup, any recommendations for a good scan tool?

I think everyone agrees on....
LAUNCH MB CREADER ELITE
$150 on sale sometimes

It's portable and has good module coverage for every day use.
Many of us are familiar and enjoy this DIY scanner.

Excellent! Ordered and on the way. I'll take a run at it in the next couple of days and keep you guys posted.

And thanks again for the help and expertise.

this tool is gonna help you save lots of bacon... for breakfast.

Originally pioneered by Master Surya.