Mercedes ECU Up for sale is a Working, in excellent condition Mercedes ECU. Bosch Part number-- 0280800256 / 0 280 800 256 / 006 545 64 32 / 0065456432 . Comes with a 30 day functionality warranty.This ECU came out of a w124 chassis Mercedes 300E, should also fit some other 300e's and 300te's. and probably also W126 300SE & 300SEL's May fit other models/years, but as always your best bet is to match the part number to the one on your original ECU. This is one of the most common no start or random stalling problems with these cars. This can also cause emission control issues or instrumentation issues (tachometer is controlled by this as well as other functionality otems / fuel injection system) I often tell our customers to keep an extra ECU in the trunk, as if you are in a situation where 'I need this now" You will be out of $2000 at the M-B dealer.... Though not nearly as complex as a modern day ECU, The way these K-Jetronic ECU's function is through adjusting the control pressure through the frequency valve based on the inputs it receives. This will alter the fuel system pressure (and amount of fuel injected) through the fuel distributor. Primarily this will affect hot and cold starting, as well as idle quality. The need for a properly functioning ECU with this system is clear!As always your best bet is to match the part numbers with the part you need. A faulty or water damaged 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.