[cdtwoaway]

Nope. ECUs have something called a "fault memory" where the last n detected errors are stored, and that can be recovered. This is actually what workshops use for diagnosing a car.

This can give lots of information about what happened (faults could be "didn't receive message xyz" "sensor xyz gave signal out of tolerance"). But there is definitely no system trace for the communication - too many messages to really store them I guess.