With this problem, the usual first item to look at is the ABS wheel sensors, as all these systems are interlocked with each other ..the hill start assist, anti skid. all depend on it, because they use the signal for speed from the wheel sensors.
I think limp mode could be entirely separate problem.
- all are only diagnosed with diagnostic equipment.
which wheel sensor? - To find out more on a modern vehicle. you must know where to look . for that you need a diagnostic scanner tool.
i suggest use forscan
NOTE: you can use forscan to get correct fault codes with proper explanation of them - a generic fault code reader may be somewhat misleading
Here on this site - They recommend
"Forscan" which is
FREE software that you download to a laptop..you buy the interface cable.
You can join the forscan forum ..again
free, to get the software and more answers.
https://forscan.org/forum/So, you plug it in get the codes and the answers ...if you are still stuck ...you find out a bit more about using forscan from the forscan forum. when you are happy you've tracked the problems down properly and are sure of the results and
then come here for more advice on fixing it all the best.mark