Hi all, I dropped my key in the water at the boat ramp... since the remote has died (changed the battery and it worked but shortly there after died again even after pulling it apart and giving it a good clean). Never the less the key still works without the remote. So I bought a used key and was hoping to switch my blade into the used key and reprogram that key (possible)? I tried to do it with out a VCDS / Rosstech and it looks like I've tripped the Immobilizer. Thankfully I have another key that works fully. My question is - can I use the two key method (one in the ignition the other in the car door to reporgram the key) or do I need a VCDS. Alternatively - Do I need to transplant anything from the current transponder chip into the used one that I bought? If anyone has a depth of understanding on the matter it would be greatly appreciated. Edit - The car is a 2015 A3 8V, with a key start. Cheers.