Now, here is the location of most Honda ecus. In some models it is also located below the passenger’s side seat, but most of the times is in the location pictured below.
Be sure that it reads any number starting with “37820″ on its side label, as some automatic Honda’s have a separated transmission ecu that starts with other numbers. Below is an example of the engine ecu of a P04 ecu. Note that it begins with “37820″.