has all the Mode-6 (trouble codes) data about the Volt.
Its clear they have a lot of trouble codes, so if you get an MIL, and get the numbers from onstar or an OBDII device you can at least look them up. Maybe I'll convert the DTC into codes for the torque andriod app.
Also some interesting tidbits about battery and other elements at the very end.
(Note I realize this is a repost of material in another thread, but that was on software.. I realized it may be more helpful in this forum subtopic too).