Your MFD was probably not purchased with a mapping key. Use CHECK -> MAINT -> (ABOUT) to see if your KEYS: has MAPPING. If it does you need an SD card with map data installed. Otherwise contact sales with your serial numbers and they can get you the unlock code.
Its not in the manual but the [ENGAGE] button is the extension of the Trutrak [EFIS] button. Pressing the [ENGAGE] button will cause the autopilot to turn on and follow thecurrent AP/FD settings from the EFIS.