Toyota Repair: ECU programming, toyota sienna, toyota

Question
A 2001 Toyota Sienna with proven bad ECU (engine control unit). I obtained a replacement from a used parts place. The original ECU will start the engine but there is a problem.

The replacement unit will not start the engine. The guy at the parts place said it has to be programed first.

From every thing I read the ECU assumes the engine will start.

Which way is correct?  If it has to be programed, how do you do it?


Answer
As far as I know the ecu is not programmable and should work if it is the correct part number, compare the old part number to the replacement unit and make sure they are exactly the same, if os, the ecu is either bad or there is another problem with the engine control system.