If you mean the faults stored in the various ECUs in the car, then they use a KWP protocol (mostly) and are read with a system known as T4 (Testbook version 4.Computer Diagnostic System). As far as I know, a comprehensive list of all possible codes isn't available as far as I know.
Thanks for that, i have had a diagnostic done today and it came back with 2 error codes. 1. CODE001:(81,88,1,ff)88,01 refer to relevant ff technical manual. 2. CODE002:(81,88,2,ff)88,02 refer to relevant ff technical manual. Any help on these would be brilliant, thanks again, Mick.