Try turning in on the low pressure adjustor, maybe a quarter turn. I've worked on a few I2/3's which had the tension in the adjustor weaken over time and under certain conditions would time out trying to re-level because it didn't have enough juice to move the car on low speed.
Not sure what that fault would indicate though. If I remember correctly (maybe from a thread here, and things I've seen in the field), earlier TAC32 software would check for certain parameters on start-up and trip strange faults because a hydro has different parameters than a traction and the software was looking for traction parameters. Later versions perform that check later on in the start-up after it knows its a hydro. I may be mangling this explanation but functionally this is what you get, and maybe that 115 is related?
