Some advice needed

would be nice to know what engine and year but the first thing i would check would be air to air system so clamps hoses including the one to air compresser air filter and charge air cooler
does the truck have a whistle when it is running

 

low engine power and tranny cant shift as wants)

 

Check the boost system first from the boost o rings under turbo to charge air cooler all te way to intake manifold make sure you don't have anything leaking I deal with ved12 on a daily basis and they are notorious for leaking boost once they do power goes out the window along with fuel economy also see if you can replace the boost sensor on intake manifold not saying its going to solve you're problems but once you remove the sensor if its original you'll see how bad it is. As far as software d12 uses vcads pro and you really won't be able to change that many parameters its more for diagnostics the only people that can change the parameters are volvo dealer. Once you check the boost make sure you check the fuel pressure as well you're looking for it to be around 40 to 50 psi on idle and it goes up to 70 80 psi on high idle as far as you're code mid 130 its not an engine code it looks at first like something with datalink but ill let u know what it is in a couple of hours start with those two things and let me know how it turns out

 

you should be able to pull tranny codes up on the dash could be as simple as needing a clutch adjustment or could have been a bad clutch job loose clutch bolts also does it have air or electric clutch do you have right amount of air and there is a 50amp fuse if its electric take it out and check the connections

 

U might be able to down load road ranger off line that should let u check trans codes