Gearbox Failure

[juxtaposer]

Hi all,

I purchased this car (a 2006 530d automatic) about 4 months ago. At first, it drove very well with no issues at all to speak of. However, over the last 2 weeks or so, I've noticed it's been a bit jerky changing gear from cold. I decided to change the gearbox oil and filter and see if that made any difference and was due to do so this weekend, but this morning on the way back from the shops I was startled to notice I was rolling backwards down the hill I was in the process of climbing, having stopped a moment to let some disabled children cross the road. Normally the forward drag of an auto box keeps me stationary without need of any brake when I'm on an uphill stretch, but there I was, slipping backward. Then when I tried to pull away I had to use a lot of revs and when it did 'bite' it seemed very sluggish as if it were stuck in 3rd gear. I got a red message come up saying "transmission failure you may find it impossible to engage reverse gear" and a warning to drive slowly and carefully. I was able to get home about 1 mile away seemingly stuck in something like 3rd gear all the way.
So.... is she a goner? I'm guessing this is going to be very expensive to put right.....

[jclausen]

If the trans goes into fail safe it will be locked in third gear so acceleration will be slow from a stop and at higher speeds the rpms will be high say at 55 mph somebody needs to take a look at it and find out what happened

[juxtaposer]

If the trans goes into fail safe it will be locked in third gear so acceleration will be slow from a stop and at higher speeds the rpms will be high say at 55 mph somebody needs to take a look at it and find out what happened

Is that what they call 'limp home' mode? I went out earlier today in order to note down the exact warning message and see if there was any part of it I'd missed or overlooked and found that on firing up the engine that there was now no warning messages and reverse gear was working again! I was able to drive forwards and backwards with no difficulty; it was just as if nothing had happened. So I have no idea what to do. If I take it to a garage now it's going to be much harder for them to find the fault given that it's clearly of an intermittent nature and can presumably come and go randomly. What a damned nuisance.

[Basilbrush]

There will be codes logged int he TCU, the garage should be able to check what these codes are. don't get the parts gun out for this fault as everything for the transmissions can be a bit pricey.