Thought the 2010 xkrs came with LSDs but recently got stuck in snow and only one wheel spun. Seems like an open dif

 

Electronic diff, not a true LSD. Probably other factors than just rear wheel rotational speeds involved, like maybe vehicle speed.

 

Which of the two active duplicate threads do you want to keep? An Admin or Moderator can merge them.

 

Electronically controlled limited slip differential. The clutch plates are located in the differential.
So, a motor engages the clutches to couple the rear axles rather than using an internal mechanical device or selectively applying brakes.
The function (clutch plates, motor) on your 15+ year old XKRS may require attention.
Did someone turn it off in CCF rather that repair it to extinguish trouble light, diagnostic codes?