Hi John
If you have anticreep and speedhold you have a dg
I think the anticreep devices on the dg box often fail, I removed the solenoid underneath the car. Even when new there were reports of them locking up
I repaired the speedhold function on my car earlier this year and it is well worth doing, the previous owner had attempted this but could not cure the oil leak from around the solenoid that pulls the rod that stops the car changing up into top
If you want some help with this I can help
If you are lucky it may just be the wiring or the solenoid this is a reasonably easy fix and there are access holes either side of the transmission tunnel( at least there is in a mark 2) so you can just about get away with doing the job/ testing the parts without jacking the car up. Although if you can jack it up this avoids lifting the carpets if they are glued down. Testing the wiring to the solenoid is easy, just check you have 12 volts to ground with the switch in the in position and then check the switch turns it on and off, if there is no voltage you can test the solenoid by pulling 12 volts into the wire an listen for a click
Graham whitehouse auto transmissions and automatic choice were a great help in supplying parts and freely giving advice to help me fix the box. Graham said these boxes are very tough, more so than the bw 35,
With mine I had to take the tail piece off the gearbox as a couple of the seals in the box were missing causing an oil leak. This was a very worrying time as I new zilch about auto gearboxes
As I said well worth doing because the speed hold effectively allows you to chage down at the flick of a switch or hold intermediate gear when giving it some beans down the lanes or up a hill of when overtaking, obviously you do have to watch your revs all this means more fun
Cheers
Richard