[wardy335]

Hopefully someone can shed some light on this...

About a month or so ago I went to start the car and it turned over very slowly, it eventually started and returned just about every single warning light possible, DTC failure, ABS, Gearbox malfunction, tyre pressures low - the lot. I had no idea what was going, couldnt even move it as it wouldnt let me change gear (have since found a way to overide that). I assumed it was the battery, so put it on charge - next day fine. Brilliant

Only, it did it again at a mates house, managed to overcome that and get home. I thought it must just need a new battery. I took it to a BMW speciallist near me as it needed a service anyway, and he siggested he put it on his charger as it has a gel battery and normal chargers dont charge these up properly. So I've had the car back a few days from this service only for it to do the same thing again

I turned it off, started it immediately after and ok, no warnings, so it cant be the battery, must be an intermittent fault. The battery is also only just over a year old, replaced before I owned the car going by the date stamp on it.

From what I've read, people seem to have problems with the IBS cable, which links it to the idrive or something so it can work out how much charge to draw for the efficient dynamics. Can you just disconnect this cable and tell the ED to sod off? its not like I bought the thing to be 'efficient'. Something is buggering up the start sequence, and quite frankly its doing my head in.

So has anyone had similar problems and have a solution? Would apreciate any feedback

[KM79]

It can still be the battery itself.Could have a faulty/loose cell where sometimes it's ok the next it's not.If the battery has suffered a total discharge at some point in its life then an AGM is classed as to be replaced as future faults will occur.Generally you can check the effectiveness off the charging system and IBS by checking the output voltage and current of the alternator by trying different loads on it ie lights on/ heaters on/ heated screen on etc

[wardy335]

Thanks for the reply Kris, I take your point on board, but would it still be the battery if say a couple of seconds later you restart it and its completely fine? I tried disconnecting the IBS lead and that just threw up a warning saying high discharge. The chap who did my service said there were no faults to clear. I don't really know how to sort this without chucking loads of money at it.

[KM79]

Yes either that or poor battery terminals connection?

[wardy335]

I think you might be right, it must be the battery, even the seat belt assist thing cant be bothered to work now and the fuel gauge says 0 (which isn't that uncommon for this car lol)!

I will buy a new one so at least I can eliminate that as one of the problems, if its still going wrong after that then I guess its back to the drawing board. Never realised what a mindfield it is to buy a bloody battery. Think I've found one that is closest to whats in there at the moment, i.e AGM, 80ah etc. Just need to code it to the car now

[KM79]

Yeah that's the car disabling various electrics to conserve battery current.sounds like a battery to me!