[driveseeker]

I was preparing my 2013 335 for a big trip the other day, and after a quick detailing, left a couple of doors open to let the car air out. Big mistake. A few hours later, as it got darker, I noticed the front amber parking lights were on and the battery was low. The lights would not turn off. I hooked up my charger, but the lights stayed on and as the battery gained charge, the rear red parking lights came on too.

A quick search found nothing on Bimmerpost, but interestingly, a 2007 post on 5series.net had this:

Keep in mind that this bug happens when the headlight switch is in the "auto" postion, not when the parking lights are actually switched on. In other words, if you're stopped on a dark road, you can turn the parking lights on and they'll stay on until the battery dies, regardless of what door is opened, etc.

The software bug we're talking about happens when the the headlight switch is set to auto, the car has been sleeping with the key in the ignition, and a door other than the driver's door is opened. When these conditions are met, the parking lights (or headlights if you have a really old CIP version) come on. The lights will stay on until the driver's door is opened or the battery dies. (https://5series.net/forums/e60-discu...ts-stay-35739/

Whether or not this was the cause of my problem, the circumstances were identical. The light switch had been on Automatic, the key fob was in the car, and a couple of doors were open but driver's door closed. I realized no amount of charging would help as long as long as the parking lights stayed on, so I had to borrow my wife's car at the last minute. Unlike the poster ten years ago, neither closing the driver's door (nor anything else I was able to think of) would turn the lights off. On the eve of my trip I could only watch as the battery depleted, with no recourse. Major frustration and disruption of plans.

Now I'm back home and the car is being towed to the dealer today. The service advisor has never heard of such a problem, and accordingly, even though the car is still under CPO, I expect they will want me to pay for the service and the cost of a new battery. To me of course, this would add insult to injury. Any wisdom or advice on this type of situation would be greatly appreciated.

[Billfitz]

That's a fault of some sort. No matter what the power management system is supposed to shut down all the lights before the battery is drained so much that the car won't start. BTW, unless the battery is at least three years old don't believe it if the dealer says it needs replacing.

[AMG KLR]

...Did you try turning the car on and off again?

[driveseeker]

Originally Posted by Billfitz

That's a fault of some sort. No matter what the power management system is supposed to shut down all the lights before the battery is drained so much that the car won't start. BTW, unless the battery is at least three years old don't believe it if the dealer says it needs replacing.

Thanks. I just hope they find evidence of a fault or a code thrown. Battery is not that new; we'll see what they say tomorrow.

[driveseeker]

Originally Posted by AMG KLR

...Did you try turning the car on and off again?

Unfortunately not enough battery to start; an ignition cycle might well have cleared it. Not even enough to open the trunk to get the tow hook....

[Billfitz]

I guess it's not impossible that the battery was too low for the car to react. I'd have tried a jump start if the charger was too small to charge it.

[bimmer456]

Originally Posted by driveseeker

Unfortunately not enough battery to start; an ignition cycle might well have cleared it. Not even enough to open the trunk to get the tow hook....

You can open the trunk by lowering the rear seats. You can reach the lever through the center pass through and then use the emergency trunk release.

[bimmer456]

Originally Posted by Billfitz

That's a fault of some sort. No matter what the power management system is supposed to shut down all the lights before the battery is drained so much that the car won't start. BTW, unless the battery is at least three years old don't believe it if the dealer says it needs replacing.

The battery should be covered by warranty if the electrical system that caused the drain is also covered by warranty.

[Billfitz]

Originally Posted by bimmer456

The battery should be covered by warranty if the electrical system that caused the drain is also covered by warranty.

That could come down to a cause and effect decision. Did a battery on its last legs mess with the system or did the system mess with a battery on its last legs? With a four year old car I don't see them giving the OP a new battery unless they sold him a new one within the last year or so.

[bimmer456]

Originally Posted by Billfitz

That could come down to a cause and effect decision. Did a battery on its last legs mess with the system or did the system mess with a battery on its last legs? With a four year old car I don't see them giving the OP a new battery unless they sold him a new one within the last year or so.

I'm curious as to if the battery has a separate warranty as the cars at least here in the states have a 4 year warranty or 50k miles. I know some automakers have a separate warranty on the battery but some don't. They should do a courtesy replacement of the battery as the lights on situation is draining it and there's no way to turn it off.

[Billfitz]

Originally Posted by bimmer456

I'm curious as to if the battery has a separate warranty

The tires do, and if you look at it you find that for all intents and purposes there's no warranty.

[bimmer456]

Originally Posted by Billfitz

The tires do, and if you look at it you find that for all intents and purposes there's no warranty.

Yeah I was told the only way they honor the battery under warranty is if you can show you drive the car enough to keep it charged. I'm not sure how I can prove I kept it on a charger. So there's at least a warranty if you daily drive it. Otherwise it's $400 bucks at the dealer. I believe Sears makes one for $200 but it may be for the e90.

[Billfitz]

The BMW dealer price for a battery is a total rip off, but what isn't? The issue with getting one elsewhere and installing it yourself is that it has to be registered/reset or it won't charge correctly, and much of the extra cost from a dealer is for the 5 minutes it takes them to do that reset. What you'll save with that alone will more than pay for buying your own gear to DIY. A battery at Wally World is $140, and they're top rated.

[driveseeker]

Thanks for all the responses. In this case, the answer was the simple obvious one, not the complicated software bug issue that my symptoms happened to be mimicking. Dead battery, $250 plus 180 diagnosis/initializing labor by dealer.

What threw me off was 1) the batteries in these cars apparently give virtually no warning (slow cranking etc.) when they're about to go bad, and 2) when the charge falls below a certain threshold, the system can't operate, i.e. the front amber lights can't be turned off, and low-battery sensors that would ordinarily trigger a shut down to prevent total discharge don't work.

So apparently my battery was already on the brink (over 4 1/2 yrs. old, a lot of short trips) and when I left the doors open even briefly it was enough to drop it below the threshold where the normal safeguards would prevent a total discharge.

In retrospect, a timely jump start might have saved the day, but various circumstances and wrong diagnosis on my part prevented me from trying.

Another lesson learned. Meanwhile the original battery in my 2009 128i seems to be going strong...and I prob should replace it proactively, but I'm thinking its likely the old-fashioned type that will give me some warning before it fails completely.

[Billfitz]

Originally Posted by driveseeker

I'm thinking its likely the old-fashioned type that will give me some warning before it fails completely.

For the most part none give much warning, other than slower cranking in colder temperatures. You can also figure that if the battery is rated for a certain number of months it will die not long after that. I get much more life from mine than average because when the temperature drops below freezing at night I use a trickle charger to take the load off the battery and keep it from doing much cycling. Even in a warm climate I'd do that if I seldom drove it, or only drove short distances.