2012 C250 with barely 19,000 miles, no problems, no indicator lights, nothing. Drove it last night with no problems. Parked it and locked the car last night by touching the door handle, lights flashed and the car beeped. Walked up to it this morning and the doors were unlocked - sat in the car and noticed the headlight indicator lamp and the rear fog light indicator lamp were both illuminated in the gauge. Looked over at the light switch and, as always, it was in the "Auto" setting. Pushed the Keyless Go button - nothing. Popped it out and tried the key - nothing. Pushed the door lock switch - nothing. Dealership said they couldn't tell me anything without having it towed in and looked at (Monday...ugh), so I'm in the process of doing that.

Sounds like a battery but after only 19k miles would I really need a new battery? And what's with the headlight and fog light indicators being on (exterior lights weren't on - I checked). I don't leave anything plugged either - only plug in the cell charger when I need it. And if it is a battery, is that covered by my warranty?

 

I had a similar thing happen to be when my battery died. Weird light indicators and even said air bag error. I freeked out a bit and called roadside. I tried the car 30 mins later and it started but hardly. Try jumping it, this will tell you right away.

 

You are doing the correct thing as you are under warranty & don't have a multi meter or charger.

We are looking forward to knowing the cause.

Maybe safest to leave your lights on manual off ?. Maybe a 'keyless go' one off glitch?.

With an impending flat battery does the system fail safe open the car doors?

 

Ended up having MB roadside jump me off - car started perfectly the rest of the weekend. Took it to the dealer this morning and let my Service Tech take a gander - apparently my headlight switch was malfunctioning and the lights weren't always automatically turning off. Honestly, I never have sat and watched the lights go off after however long they're supposed to remain on.

New light switch ordered, and a new battery popped in, all under warranty. Should be ready by tomorrow afternoon.

Side note: apparently when the battery dies, the doors unlock. Seems a little ridiculous, the valet key allows you to unlock the doors manually...and my doors auto-unlocking just because the battery dies put whatever's in my car at risk.