Diagnostics? There are some LEDs on the side of the box that flash when locking or unlocking.
There are valet, parking light flash, dome light, horn features, etc. but I did not bother with any of that.
The DMCH-supplied instructions get you to the point where it does what the OE module does except better, as noted already. It's a 5 minute install at that level.
You could call them if you want to verify or get details.