ECU/PCM replacement issue
 

I purchased the ECU for my 2005 Mazda 3 auto. I purchased the ECU with part # L3ZF-18-881R-0E, which should work on my vehicle. The part # that is actually on the ECU is L3S3-18-881B.

I went ahead and replaced the 881B ECU with the 1R-0E ECU, and the engine does not start. I get all the lights on my dash, but car won't start. Do I need to bring it in to the dealer to program the ECU? Can I program it myself? Is there something I need to do in order for my car to recognize the new ECU?

thanks!

Just doing a quick google search...
The one you took out seems to cost around 100-180 bucks.
The new one you bought seems to run around 500 bucks.

I'm thinking they're not the same thing, even though I'm as confused as you.