Weird ABS problem that stumps dealer

thanks for all the responses, just recently the truck has thrown a few more codes and apparently the codes are related to the brake codes. I know it threw 3 transmission codes one is FMI 8 and mid 136 cant remember the last one, but I was told the were data link codes between the transmission and other computers so a good chance it may be a programming issue any ideas? truck has 47,000K on it and the problem has not changed since the truck was brand new...

Foxcover over all I love this truck, hard to beat the ride and room inside my truck has 47000 kilometres on it now and nothing at all has gone wrong with the truck at all, (except for the abs light). I was really pondering which engine I should get, took me 2 months to decide and I decided on the D13 why? well I talked to many different volvo Mechanics and 4 different dealerships and only one out of 6 mechanics I asked leaned towards the D16, the majority basically stated that the D13 was more reliable, cheaper to rebuild, simpler design and easier to work on, I also asked a few drivers what they thought about the D13 and I heard all positives
There was one driver I remember tho, he owned 3 volvos 2 were D16 and his newest one (09) other's were 08's was a d13 and he stated the D13 out pulled his 16's BUT he was into heavy equipment hauling and his 09 had gone through 3 Ishifts since he bought the truck all replaced under warrenty tho. otherwise I have hard alot of good things about the Ishift I like it alot, it's not perfect but it works alot better then the ultra shift... my advice to you tho Buy the VIKING GOLD extra warranty 500,000mile or 5 year warranty on engine and alot of the truck and the tranny is warranted for 800,000 miles or 7 years. dont just get the basic and keep in mind the platinum warranty may cover a few more items but every time u bring your truck in it will cost you a 500 dollar deductible. also this truck has 3.55 gears which I believe with the I shift is the way to go if the truck has 22.5 tires on it, if it has 24.5 I would prefer 3.73's at 60mph im doing just under 1500rpm, oh and if you can make sure you get full locking diffs and make them super 40's

 

oh here I have the exact codes it threw

Brake ECU

:MID 136
:SID 2
:FMI 7

Transmission Ecu

:MID 130
SID 204
:FMI 8

 

would that be why sometimes it holds onto gears then when it shifts it may shift 2 or 3 gears in a row quite quickly like it will be in 1st gear, hold onto it till 1900 rpm then shift to 2nd but realizes the rpm is still to high then shifts quickly into 3 but then senses the rpm is too low so it lugs lol.

But why would everything be 100% at speeds under 90kph and i could drive around all day at apeeds under 90 and it will never trigger a code, but over 90 for 8km ish both lights trigger every time?