Hi buddy, like said above if you've got an android phone then all you need to read the engine codes is this http://www.ebay.co.uk/itm/V1-5-ELM3...iagnostic_Tools_Equipment&hash=item53fc787f0b and the Torque app on your phone, job done for less than £12. If you want to read the codes on other modules in the car, ( brakes, climate control, central locking etc etc) then you will need VCDS which is a couple of hundred quid for the genuine one! Torque app can read and reset all the engine codes plus you can read the data from it as you are driving and display it on gauges or graphs of your choice. If you've got an Iphone, then thats your fault for having an iphone, lol
VCDS can be had for £12 http://dx.com/p/jtron-090035-can-vag-com11-11-car-diagnostic-tool-black-232902