VW ECU Up for sale is a Working,good used in excellent condition Vw Golf / Jetta Digifant II ECU. VW part number 037 906 022 AJ . This ECU should fit many Golf/Jetta models. As always your best bet is to match the part numbers with the original unit in your car. These are located in the cowl (where the wipers sprout out of), on the passenger side of the car, under the metal bracket. Comes with a 30 day functionality warranty! A faulty ECU is one of the most common no start, start-stall, or random stalling problems with these cars. These can also cause issues with erroneous check engine lights, idle control problems as well as emission control & cold or hot start problems. I have also seen fuel pump relay turn on faults (ECU won't turn on the fuel pump), as well as an condition where the high speed injector driver has failed. This causes the car to sit and idle fine, but it won't accelerate.This is a bargain price for a replacement unit, about 1/10th the dealer list for a NEW one. Even If your car does not have these issues but you intend to keep it a while, I recommend our customers keep an extra ECU in the trunk. These units now have to be special ordered from most dealers new for big $$ (often times over $1000!), and you can never find one when you need one. Even now finding a good one second hand is getting to be quite difficult as these cars get older.