VW/Audi ECU Up for sale is a Working, in excellent condition 1985 Audi ECU. VW/Audi part number 811906264D Bosch part # 0280800134 . This ECU should fit many 1985-1988 Audi Coupe GT's 4000 5000 & Quantum models. the Came from an 85 model. This comes with a 30 day warranty. Please be sure to check the part number off of your original ECU before buying. This unit controls the fuel mixture of the K-Jetronic system through inputs from the o2 sensor & others. It primarially adjusts the mixture through adjusting the fuel pressure (at the extra in-line injector), though it also performs other functiond as well. As always your best bet is to match the part numbers with the part you need. A faulty ECU can cause a whole hots of issues with these cars, including non running, and random cutting out (but usually it will re-start moments later). Also idle control & emission issues are possible (excess smoke or overheating caused by lean running). Hot or cold start issues can be caused as well. These units are no longer available almost everywhere and VERY hard to find used. If you can find a new one, they are usually in the $1000+ range. Ouch, not here! This comes with a 30 day warranty.