Hi
your generic code reader will only engine fault codes and only basic codes at that
so any trans, heating, airbag, suspension, braking, cruise, abs, audio, door locking and many many more modules wont be read, on the s-type, after 2002 every thing is fly by wire, so every light bulb, sensor, relay, motor or solenoid is control by either a module or control unit, wont be read
if you want the proper thing you want a mongoose lead which comes with software jaguar IDS/SDD , which can do every thing jaguar can
IDS is for pre 2005 cars and SDD is for post 2005 cars, Version 130 or 131 is best, it will do all cars, all S-types, later version are for later cars, later version dont have IDS so is not backwards compatible
mongoose lead and software can be bought for around £100 but need to be installed on windows XP pro, but some come with a emulator type software that will work with window 7 onwards, but its not as stable as the windows xp pro, version
I installed mine on a dedicated laptop, laptops for windows xp spec can be bought for around £50
cheers
Joe