Check the pads, there may be gravel or other debris on them that is setting off your sensors.
As noted above, check your hydraulic fluid. Unfortunately, if your coach is a 2008, it may have been off the assembly line in 2006. The hydraulic fluid may have water, or other contaminants in it.
has great owner's manuals and maintenance manuals for their systems.
I stopped by Power Gear in July. They are working, but on a skeletal crew. I would try calling them, but I wouldn't be surprised if you do not get an answer.
How about your dealer? You can also call GS customer service. The operator is helpful and will route you to your area rep.