Well, what year and model is your car? If it is a 95, you may run into issues with EWS. If it is anything above that, you don't have chips, you get the software flashed. Now, if you have a 92, then you need to make sure the chip was made for your ECU/DME. For 92, I believe it was either the 402/403 Bosch ECU. Years 93-94 were 413, and I believe that 95/95M3 was the 509/something like that. You need to make sure that your chip matches the ECU or it will not work. The maps are in different locations per ECU, hence why your car probably doesn't start.
Also, before ever opening up your ECU, ALWAYS UNPLUG THE BATTERY. I can't stress this enough. Unplugging the battery should be your first step when messing with any electronics in your car.