Replacing BCM

The turn signals are intermittent. Sometimes one works, but usually neither work. After 8 days at the dealer, they said the BCM was bad. I chose to repair/replace it myself to save approx $500. I found a used one online (exact P/N) and replaced the module (battery disconnected), but the car would not start with the new module. It would turn over, but not start. Blinkers weren't working either. Is there a 'reset' method that must be done to get the new BCM working properly, or is the BCM I bought no good?
Any assistance would be greatly appreciated.