hi I've got my airbag reset tool today from uobd2 I've plugged it in to the plug in right hand side of driver footwell tried to reset but it just fails i get the busy light then fail so has anyone got any advice as this came with no instructions ie should ignition be on/off or anything else I may be doing wrong the car is 2003 a4 tdi I've also tried reset with both bottoms red/yellow