20 years ago I worked for a diesel engine dealership, at the time I was the guy who was the go between the factory and dealerships on techinical issues, etc. The ECM on the engines had the ability to log data for 60 seconds before and after a code was generated no matter what the code was ie. oil pressure drop, coolant loss, quick stop, loss of fuel pressure etc. The data would include speed, rpm, clutch position, Jake brake setting, TPS position, brake on or off, anything that had an input to the computer it would log, about 20 things if I remember corecctly. It could also log some data for a lifetime but I have forgot what that was.
Anyway there was a fatality accident involving a tractor/trailer that flipped over on an off ramp. The state patrol detectives brought me the ECM and asked me to down load the data, I told them I couldn't do it because of that is private information, etc. They said fine they'll be back with a search warrant and they did come back and I have to give them the info.
I don't know what the answer to the question is except to go back to carburators and points but the data is in the ECU's and with the factory "keys" it can be unlocked and read after an accident.
Food for thought my friends.
