My R350 2008 won't start. It's not the battery. Could it be the SAM unit?

Check battery!

If voltage goes below 9 then battery needs to be charged

If headlights go very dim during crank battery needs charge

If after charge same result replace battery

Hope this helps?

Before replacing expensive units it is worth checking the basics.

The symptoms you describe indicate a battery with problems or a car with a fault causing a constant discharge as if perhaps the boot or trunk light is not switching off, for instance.

I suggest battery is charged and tested and if ok check for a discharge. I once had a car with automatically closing windows and one of the motors wasn't switching off after the windows closed causing several discharged bat before I discovered the cause.

Check all your fuses . Remember you have more than one fuse box. If the fuses are good ,then it looks like a problem in the SAM unit,, it works all equipment /Check for water ingress in the same area as the SAM unit it will cause problems if its wet..

Have you had dead battery? cause to jump start,or a new battery installed? Problems arise in the MB SAM unit in the trunk if proper procedure is not applied..It an destroy the SAM unit,cause a coule gage indicator problems,etc..Take it to or dealer..MB is nice,but finicky car Good luck...you may spend up to about $300 on this though..

Don't you have some warning lights on your dash? MB cars are fly-by-wire that tend to depend so much on battery electricity when shut off. Use a high amps battery or battery recommended matching your car model. Check on some instruments that can be a parasitic drain to your car like, car alarm, sticking relays on auxiliary fans, radios. Worse you have a short somewhere or a wiring harness issue, but it should be giving you a warning on the dash.

Try www.reliable-store.com , it's very helpful
in repairing your vehicle

It is in Theft lock from the loss of power. Contact your local dealer for help getting it unlocked.

It wold be the faulty SAM according to my knowledge your technician have told you what's wrong in it. must check the front SAM and rear SAM as well,

hello,hoping they right,maybe your front sam is switching a electrical consumer,even your ignition key is out,resulting your battery drain,if possible ,request your dealer a print out regarding front sam actual values and specified values for your reference,ty