I need to replace my PCM. I have the directions for the dealer to program a used one. BUT my question is, do the part numbers have to match exactly? It is proving to be very hard to find one that matches my P/N. On the other hand, I am finding many available that are coming from the same year car, with the same engine size and same transmission. But they have different part numbers. SO, is it super vital that the part numbers match, or can it just be programmed to my vehicle!? '08 caliber SE, 1.8L, manual transmission, no alarm.

 

If the drivetrain is the same, I would think it would be programmable. I know that there can be many different calibration ID #'s one one model year.