I am experiencing an intermittent Fil Safe mode and the cruise control gets knocked out too. Any insight on what may cause this to happen? It resets when I turn the car off and the restart, but eventually it comes back.
many thanks in advance

 

It's protecting itself but struggling to say why.

Try OBD. You probably won't find any codes but might find pending ones. (Don't clear any!) Check live data for any odd values. Check all OBD monitors are set (aka complete) and if any aren't then they are clues.

 

Aye start by reading codes, but I'd guess at the brake light switch as that works with the cruise control too.

 

Yes, check the OBDII codes.
I bought my X308 in such a condition way back, and in my case it was the knock sensor that wanted to get replaced, The OBDII reader told me as much, too.

 

Fail Safe for me was a failing transmission. Overhauled it and zero issues since. Read codes though.

 

Transmission is fine, but I am familiar with this possibility from previous Jags I've owned, thanks