H2 sat for about a week. Started up battery a little weak. Check Engine light came on. Drove and restarted twice. Returned home charged battery. Engine turns over no start. Disconnect battery cables and slow charge battery all night. Reconnect battery and vehicle started, no check engine light. Replaced battery. All starts fine drove about 30 minutes, park and will not start, turns over and check engine light back on. Wondering if this is pass lock or ignition switch

 

Go by Autozone and have them check the codes.
Or get the $10 OBDII BT reader and do it from your smartphone/tablet.
That code would help a lot right now.

 

Son ran code reader. Fuel pump control module disconnect.
Suggested fix replace data bus cable

 

Best I could find. Seems like the connector has problems.
http://engine-codes.com/uploads/gmc/08-07-30-021E.pdf

 

Made it to dealer today. Started fine after hooking battery up. Engine light came on approx 5 minutes after starting. And at dealer they started it several times. Unknown!

 

Fuel pump and fuel pump contro module.