I replaced the original 1.8 turbo (oil sludge) with one from a 2003 passat (27,000 miles). Everything connected up fine. I replaced the timing belt before installing the newer engine, just to be safe. The engine turns over but will not start. The fuel pump will not run and the ignition coils will not fire. What would cause this situation?

Your new engine.

Your new engine.

Wrong engine code. 02 has different ecm than 03