Engine Mechanical problem
2003 Chevy Suburban V8 Two Wheel Drive Automatic 100000 miles

facts and evidence:
1. Happened to be very low on fuel and not driven for 6 days. (go figure!)
2. When started on the 6th day, it was as if the battery were DEAD, then it very slowly turned over and started.
3. The message "Reduced Engine Power" displayed and the vehicle would not go more than 5 mph. Parked it and retried several times with the same result.
4. Then it started hard but ran fine except for slow windows and reduced AC coldness and output.
5. Put gas in it but have had the same experience each day since.
6. After another episode today (day 8 since the initial problem presented) I was blessed that I wasn't stranded
7. Now the "Check Engine" light is displayed. (sounds like a good idea but funds prevent that right now and we have 5 children and our other vehicle is a Camry)
8. The battery has obviously been asent since the clock resets now every time it starts.

8. On the side - in case it could be relevant - the speedometer sometimes malfunctions and Chevy has let us know they are aware.
The driver's seat suddenly decided to reverse the direction of the controls.
A lighter power source quit.

take it to a local parts store like auto zone or stop by are 2 car pros store and pick up a scan tool. then get back to me with the code and i can help you