bigslick7878

So was pulling into a parking lot today and the car just shut off. Had plenty of aux power for lights and what not but after trying to restart wouldn't turn over. This has happened twice in the past 6 months both times I just thought it was random or I hit something by accident. But those times, I just turned the car completely off, then tried to start and started right up every time. There isn't an immobilizer that could have been tripped somehow is there this time?

But anyway I know there are two batteries, does it matter which one I hook up to? Under the hood hopefully and not in trunk? I really don't think it is the battery but before I get it towed I am going to try to jump it tomorrow. This feels a lot more like an alternator that was going out and finally bit the dust tonight with the two previous times it happened. But at 75k miles?? Weird. It is a 2015.

DFWdude

Jump start it as normally advised... Connect to the Main battery under the hood only. There is a positive lug separate from the battery (under a sliding cover), and a brass grounding post on top of the wheel arch near the shock tower. I'm not convinced the battery is your problem, but it's the best place to start, in any event.

(BTW, this thread belongs on the W212 forum for a 2015 model.)