My 2009 XF is in Limp mode and I am seeing these error messages; Engine system fault, parking brake fault, dsc not available. I'm also seeing P2135 TPS/Pedal position low voltage when I use my OBD2 scanner. Someone told me to replace the throttle body, has anyone seen this problem before?

 

More likely to be a pedal than the throttle body. I would suggest actually checking the values before throwing parts at it.

Also, it looks like an animal is living under the hood of this car, have you checked the wiring to make sure nothing is chewed up?

These are the circuts it calls out, based on what the full code says will tell you what type of failure is being seen, you could verify fairly quickly with a DVOM at the ECM.