[algae105]

Hi,

I have a 2013 X3 that has given us no trouble in the last 7 years of ownership.

A couple of days ago, when I tried to use it (it had been working fine with no warnings the day before), it was completely unresponsive. Tried both keyfobs but neither could unlock it. I could get in via the mechanical key and the alarm was working along with hazard lights but that's literally all. The dash displays were dead and so was the radio and interior lights.

I figured the battery had died and called a roadside repair guy who applied power through the bonnet points but this didn't make a difference. We couldn't even release the parking brake to tow it because that was also not responding.

Finally, he disconnected the ground terminal on the battery for a couple of minutes and after reconnecting it, everything came back to life and the car started without any assistance.

It's now in with a BMW dealership but they report that it starts fine so they can't see a problem.

Has anyone seen something like this before ?
Does it indicate a particular component is failing ?

Basically, I'm worried that the dealer will say there's nothing wrong with it now and we'll be stuck waiting for the next time it happens. Given the hassle with getting to the battery when all doors are deadlocked, I really don't want to be stuck far from home if it happens again.

Grateful for any help !

[383vett]

If this is the original battery or 7 years old, I would start by replacing the battery making sure the terminals and clean and tight.

[Qsilver7]

Originally Posted by algae105

…I figured the battery had died and called a roadside repair guy who applied power through the bonnet points but this didn't make a difference. !

Do you know what the roadside person connected the negative clamp to? I only ask because over the years I’ve seen people connect jumper cables or a battery charger’s negative clamp to a random nut on the shock tower or some other metal part that they think is grounded…and it is not. Thus trying to jump or charge the battery…ends in failure due to not being correctly grounded.

If you don’t know where to hook up jumper cables…make sure you know in case you have to do it or rely on someone else to do it…if they hook them up wrong…you can show them where to correctly put things.

Check your owners manual for the correct locations, then raise the hood to verify so that you know for sure in case you need to jump or charge your battery in the future.

Here’s examples from some F chassis BMWs…sometimes the dedicated negative terminal is a hex nut…but sometimes the dedicated negative terminal is a simple pin-like thingy about the circumference of a #2 pencil:

[algae105]

Thanks for the info - in my case, it's like your last picture (pencil-thickness post sticking up from the front-left (as you face the car). The recovery guy used those points and was able to get a good reading from the battery. It was "a little low" but after the battery was reconnected, the car was able to start several times under it's own battery power.

I agree the battery may need to be replaced because it is over 7 years old but I'm not sure that alone could explain the problem we had. It looked much more like a "computer" issue where a hard reset seemed to clear some error condition.

[Qsilver7]

…thanks for the verification.

[algae105]

And sure enough - the BMW dealership said they could see no faults recorded and the car started without any issues so there was nothing they could suggest. We just need to wait for it to happen again