Since mid last year I've had issues with what I call transmission "slam". I think the "slam" that I get is similar to other 530d owners - the "slam" occurring when the gearbox changes down from 2nd to 1st as the car comes to a stop. The change up from 1st to 2nd was also affected, but rather than a slam, there was a slippage and a very significantly longer shift time. The symptoms are different from the "slam" described by 545 and 535 owners from what I have read.

My dealer said the problem was due to the age of the car, and the fact that diesels were hard on transmissions due to the higher torque output. Tried to sell me an extended warranty. I changed dealers, luckily we have 2 in Auckland. My problem was intermittent and somewhat helped by the 20 second reset, but not cured and reverted back to the slam within a day or two.

While detailing my car after our South Island trip I had the stereo going, interior lights on etc and got the battery run down - original battery, almost 6 yrs. old. When I started the car to charge the battery, it made a few extra clicking sounds, something drew my attention to the iDrive display and I lost all my stored radio stations. Managed to start the car and thought nothing more of it. Next time I drove it, the transmission was as smooth as the day I got it - probably better. Great - but how long would it last? Well, it's been 24 days so far?..

So any tech people know what happened? Will it come back?

Disclaimer: No promises that this will work for you......

 

is it a case of remove battery terminals? for a reset?

 

No. I removed the battery terminals when I fitted my msport wheel late last year and that didn't do anything.
I don't know the technicalities re the low voltage, just describing what I think happened. The gearbox is still fine so I'm happy.