So I was driving my 07 Chevy Avalanche LTZ 5.3. When the Service stability track came on. This would happen from time to time and it goes away as fast as it pops up. I park my truck and go into the store. When I start my truck back up it is running really bad. The service 4 wheel drive is flash, stability track as well. Gas and Tach gauges are going crazy. Speedometer doesn't work. The truck has like no power. I floored it and barely moved. I pulled over and turn the truck off. After that it would only start like every 15-20 key turns if at all. I replaced battery and limped it home. Connected OBD scanner. It does not communicate. I have replaced battery, starter and ECM. Same issues. It will start better now but I have to hold the key for like a minute sometimes before it cranks. I Replaced ribbon ground to back of engine block. I test for power and grounds at OBD port. When I do drive it it shifts really hard and limited power. I am lost at were to go next. Any ideas would be awesome.