well it's the value that is read from the OBD2 scanner. I tought that 0 would mean no advance, no retard; positive = advance and negative = retard...
In the program, it's called "Ignition timing advance for #1" (www.autoenginuity.com)
According to http://www.msu.edu/~guentche/guentchev/OBD-II/int-obdii.html, it means:
"The ECM-mandated advance of the ignition timing measured at cylinder #1 in degrees. This does not include any mechanical advance."

Maybe someone can explain me how to interpret those results!

I will scan another same car this week to compare.

Also, maybe my car is CAN. I tought no W202 were CAN, but maybe... if yes, that would explain why the values are off.

Etienne