I have a 2008 LTZ who is 192,000 miles young. Not really had too many problems with her except for normal wear and tear until recently. She started showing a suspension service dash lite then began shifting hard from lst-2nd with intermittent erratic speedometer. Hooked up the OBD and there were a number of codes that showed up: p1133, po69e, uo101, uo100, uo073, po700, uo109. Mechanic said it could be due to ground connection on body rail under driver's door could be corroded or gunked up. I disconnected the battery cables, disconnected the ground wire, cleaned connection, reconnected the connection and the battery cables then went for a 10-15 mile ride. About the same except instead of hard shift, harsh shift now. Parked the truck. Next day started up, sitting in the driveway and she started to run kinda ruff. Turned her off and 5 minutes or so later, she wouldn't start. She'd crank or turn over but wouldn't run. Another mechanic looked at the truck later, obd showed same codes that I got. He tried starting, she ran for a short time and quit. Wouldn't run when tried again, hooked up jumper cables and she would start. Beat on the gas tank, she ran for a little then quit. Said I needed a new fuel pump at about $450. I know some of the codes said that communication with ECM, PCM, FPCM, the oxygen sensor code, and the CAN BUS code would they have anything to do with the fuel pump itself? What about the shifting, any codes apply to that? Any and all help is appreciated.