I have no lights working on my dashboard, my gauges aren't working when I drive, and I have a personal settings error messge which caused it, can anybody help??

SOURCE: 2003 Cadillac Deville stalls while driving

Check your pending trouble codes, could be your crankshaft sensor b...

SOURCE: Quits running and engine light is now on!

I am having the same problem... My solution was to check for pending trouble codes, which is a sensor about to go out... Mine was a crankshaft sensor b trouble code PO385 and PO356.. You might want to check it out...I have 80,000 mile today also 03 deville V8 4.6

SOURCE: gas gauge, temperature gauge don't work; TC light won't turn off;

there is usually a button on bottom of the steering column to push to take the key out of the ignition. it should allow you to turn the key to the lock position

SOURCE: digital heater countrol and fuel gauge not working

i had the same problem in my 91 deville but the fuel gauge was intermittent at first, working most of the time then eventually it quit working all together, i also replaced my ignition switch thinking that was the issue but what actually happened is the fuel gauge shorted out the 16 volt supply from the bcm (body control module) which also feeds the ac and in my case the digital speedometer. your speedo probably isnt digital, but if you unplug the fuel gauge from the harness your ac gauge should come back on or vise versus unplug your ac and the fuel gauge should come back on right now im trying to locate fuel gauge. i hope this info is helpful to you, all you need to remove the gauge is 1/4 inch drive rachet and 7mm socket and a phillips screwdriver (#1) for the trim

SOURCE: my car will not shift gears or go into reverse. HELP!

So I'm guessing that when you put it in reverse and it won't move. If you put it in 1st it moves but won't shift to 2nd? And it rattles. And since you have a 4.9 in it the transmission is a 4T60E. I am going to guess that you broke the reverse reaction shell in the transmission.