We do not recommend accessing any console codes unless you've been instructed to do so by a BionX technician or by this troubleshooting guide. Changing or tweaking console codes at random is very inadvisable and will certainly lead to a system which does not function properly. Please make good notes of all console code values before and after you change them so you will be able to backtrack if necessary.
There are slightly different processes for accessing diagnostic mode depending on whether you have a G1 or G2 console. Not sure which you have? Check here to find out.
G1 Console - console code access
G2 Console - console code access