Your ECM can help you identify which Detroit DDEC engine you have.
What electronic engine management system does your engine have?
DDEC II ECM – thicker than later models
DDEC III ECM – thinner than earlier models
Detroit Diesel Electronic Controls (DDEC) is a popular engine management system used in Detroit Diesel engines, most commonly the SER 60 12.7 and 14.0L diesel engines. There are a couple of ways you can find your Detroit DDEC level, one way is to locate your engine serial number and call your local Detroit Diesel dealer and they should be able to tell you.
The other common method is to look at the size of the ECM or engine computer.
Physical Size of your ECM - how thick is it?
The physical size of the Electronic Control Modules (ECMs) used in Detroit Diesel engines varies depending on the specific DDEC level and the model year of the engine. As the Detroit DDEC levels have evolved, the ECMs have become smaller and more compact due to advancements in technology and manufacturing.
Here’s a general comparison of the ECM sizes for different Detroit DDEC levels: