Audi 80 / 90 / 100 EZK Ignition / Knock Sensor Control Unit 0227400113 / 0 227 400 113 / 443 907 397 A / 443907397A Up for Sale is a Audi EZK Ignition Control unit. This particular unit is very hard unit to find. It is in fine working condition. This unit comes with a 30 day functionality guarantee.These are generally fairly reliable units however they can be easily damaged by wiring faults or voltage spikes (caused by a bad alternator) A bad one can be noted by a random no spark condition that seems to correct itself after sitting for a short time, or a car that has no spark at all even though all the ignition components are in working order. One of the less common malfunctions with these units that I have seen is where the ignition computer won’t take over ignition control as it should and the distributor won’t advance under acceleration. This can mean the car will start and run fine, but will be overtly slow to accelerate. These units also are also typical "water damage" victims, as it's very typical for water to run down the harness into this control unit.List Price from a Bosch Authorized Service center is over $1900!These are always a nice extra item to keep in the car as well for “just in case” I have many of these, if you don't see one listed for your car, shoot me an e-mail and I can see what I have in stock. Best bet is to match the part number with the one from your car. These are very expensive at the Audi dealer, and VERY hard to find second hand. At this price, you can't go wrong.