Computer can not communicate with car when connected and car is jerking during s

Scan the other modules, first to see if it is another module initiating the fault. Then test circuits for power and ground connections to the modules, as well as CAN lines between the modules. If the ECM was bad itself the car would not necessarily run and drive.

Possible blown fuse with no power to the test connector under dash. Light on in dash? Have parts store try to read codes!!