Honda ecu location
Here is the location in the vehicle for most Honda Civic/CRX ecus. Most of the times is in the location pictured below. This happens to be true for the Civic models, while Accord models have it at the bottom of the center console. Some models use an ECM (or ECU) for the engine and one for the automatic transmission (TCM or TCU) and some other models use one module for both things (PCM).
Located the module, but not sure if it is the engine ECM? For making sure, it should read a number in the format “37820-Pxx-xxx” on its side label. The “X”s in the previous sequence can ne any combination of numbers and letters. Any other number that does not start with “37820”, it is not the engine ECM.
In the picture below, there is an example of a P04 engine ECM. The complete number is “37820-P04-G52”. You can notice that every time we refer to an ECM as the “P04”, “P28”, “P0A”, etc., we are referring to the three characters in the middle of the complete ECM number, as it is the code of the ECM “family”, while the last three are the country, transmission and software version. In this same example, the “G52”, “G” indicates that is an European Domestic Market (EDM) unit (G=”Great Britain”), The “5” means automatic transmission (5 and greater = A/T, while “0” is M/T) and the “2” is version of software (there are “0”, “1”, “2” and maybe “3”).