This is a list of GCODE commands the makerbot is using with v3 electronics.

G21
Set values to Metric
M104 S220 T0
Set temperature to 220 celcius
G90
Absolute positioning
G92 X0 Y0 Z0
Set current point to be the 0,0,0
G0 Z15
Move up 1.5 cm for test extrusion
M108 S255
Set extruder speed to 255 (max)
M6 T0
Wait for tool to heat up
G04 P5000
Wait 5 seconds
M101
Extruder on, forward
M103
Extruder off
G0 Z0
Go to Z=0
G28
???
M105
G1 X-15.77 Y15.47 Z0.36 F600.0
Move to point...
 

Resolving Glitches

One glitch i had was that my extruder would sometimes not extrude while it should be extruding. It looked like it missed a M101 command! I found the same error in this Makerbot Forum Thread

Plastic jamming up...

Start and end codes

Read this on the Makerbot Site