I'm new to computer controlled MB's, but here's what I know.

The engine ECU talks to the ignition switch and the key to form an imobilizer circuit. The keys are programmed to the VIN, which has to match the ECU. If you bought a NEW ECU, it would have to be programmed to the car.

When you connect the battery on mine you have to re-synch the windows, sunroof, and the steering. To reset the windows on mine, you put them up and hold the switch in the up position for a few seconds and you'll hear a click, you have to reset each window. Sunroof is simmilar, the steering you go full lock left right left.

If you bought a new ECU, I would think they would have to code it to your car, that's why it won't turn over or start.

Good luck, Chuck

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2000 C230 Kompressor "Frosty"

2007 PT Cruiser
2001 VW TDI Beetle
1999 Landrover Discovery II
1971 Corvette

Gone: 97 Cabrio, 83 240D, 93 VW Eurovan, 95 Volvo 850, 93 Chevy Astro Van, 77 VW Bus, 99 VW Jetta, 74 VW Bus