I have a 1996 Eagle Vision TSI I had a check engine light and had diagnostics run on it, and I received a P1781 code, which stated "4 x 4 out of self test range". I dont know a lot about cars, can you please tell me what this means exactly? And is this an expensive problem usually? I didn't even know that this was a 4 x 4, i just bought this car recently, but i see no options to switch in or out of 4 x 4 or something