A few days ago I took my Chevrolet Aveo 2004 to the workshop due to a failure.
The engine was shaking, that is, it accelerated even when in Neutral. According to the technician it is because the computer (ECU or ECM) was defective. We tried a new computer and the problem stopped appearing but it no longer accelerated to start it.


Which makes us think it's the computer. The problem is when you want to buy a new computer there are many "versions" that I do not understand and I need your help.


The one in our car has these initials "5H"
Name: Captura de Pantalla 2021-02-23 a la(s) 2.36.30 p. m..jpg Views: 469 Size: 10.9 KB

But wanting to buy on EBay many more initials appear, for example "FH", "PQ" Etc.
Name: Captura de Pantalla 2021-02-23 a la(s) 2.36.40 p. m..jpg Views: 427 Size: 11.6 KB Name: Captura de Pantalla 2021-02-23 a la(s) 2.36.45 p. m..jpg Views: 430 Size: 10.4 KB

What do these initials mean?

I'd appreciate your help.