chrclo

I have been lurking here for a while and have gotten some great help from searching these forums but this one stumps me. Basically my 2008 C300 Sport has locked itself now twice. The first time I was loading groceries in the trunk and cabin. I set the keys in the cup holder loaded the truck and back seat, closed the door and the car locked leaving me locked out. I figured I did something like bumped the button on the door or something. Wife came with spare key and all good. This did not happen for months but today the same thing happened but this time we were putting the child in her car seat and keys were set on the floor. The car locked itself with her inside, thankfully the fire dept was extremely fast and nice saying this happens all the time. But now that I have had this freak out I am on the hunt for a solution. I am wondering if there is some setting I hit or some malfunction to the fob or locking system. I cant find anything describing this behavior in the manual or these forums. If anyone has an idea or experienced similar please let me know. Thank you all in advance for any ideas!!!

JimMBC300

My 2008 C300 began having door lock/unlock problems a couple or years after it was new. Dealer could not duplicate. I found that the issues were definitely system voltage related. Replacing battery did not improve anything. Eventually the alternator had to be replaced and most issues were eliminated. Still have a minor issue, but not as you have described. You may want to have your alternator and battery checked, but in my case, the problem appeared to be an intermittent alternator failure. Dealer was not any help.