No communication between the Sam and the engine ECU

Hello,

The first thing you should do is make sure the scanner works on another car. Next here is the ALDL connector and SAM module wiring diagrams so you can see how it works and to check for power at the connector. Next there is a circuit 15 relay that power the SAM modules that needs to be checked. Here is a guide to help you with that and the wiring diagrams and relay locations to help you get started:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

and

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.

Cheers, Ken