i am no techie (understatement
) but in somewhat familiar territory here. do you have the sele warning light flashing on the dash when you have no gears? if so the gears are being locked out as a failsafe. my sele had no problems in 4 years/35K, but is locking out due to 'intermittant low oil pressure' (i got a free diagnostic run by an obliging local mechanic.)
from personal experience i wouldn't go down the parts route as described in this thread until you've tried the basics (check sele oil level and pressure, battery, pump relay and connections.)
i'm not being patronising but the good folks on here have calmed me right down.
all i need now is to actually FIX the thing
right, i've just read your post on another thread where you say you have no gears at all at the moment. i take it you've got no pump activation when you open the driver door? if so, surely your sele oil pressure is too low for gears? you can easily check this by removing the oil cap and having a look; although mine is properly filled to max line on the stick (when the system is primed), when your pressure is low and the pump has not kicked in, the reservoir will be nearly brimful (mine's about 1cm below top.) if this is your problem, from what the techie guys here said, it sounds to me like you've found a competent mechanic who might actually be right about the relay.
one more thing; if it is the accumulator failing, i believe the pump would be working very frequently, in order to keep sending pressure to it. that's certainly not my problem...i think you really need to listen for the pump activating (or not), and it's frequency.
(yesterday, i had a laugh. opened the car on passenger side, climbed across seat, popped bonnet and removed sele oil cap (brimful, as described), opened driver side, heard pump activate and ran round to watch the oil level dropping in reservoir. this told me nothing i didn't already know, but gave me something else to do.
hope this makes sense.