How to test an ECU

[Chezedik]

I know in the FSM there is a whole slew of trouble trees for testing other components that lead to an ECU failure. Is there a way to test the ECU itself though? I assume it will be a long involved test, but any help would be appreciated. I am assuming there is a break in my injection harness, and while it was wiggling it was causing a broke connection. I can only assume that it popped something in the ECU, because I completely lost injector pulse, spark, and my CEL does not light. Can I fry one that way, when the cable I was shaking was not the battery cable?