We have 2005 Grand Prix..... all of a sudden all the dash gauges go dead...the low fuel indicator lights AND I had my diagnostic scanner plugged in and all the data went blank...... turned off the car for 30 seconds and restarted it and all the things were back again.......................... Ground issue? I've heard there is a problem sometimes with the CAN-BUS ...... I've heard of a problem with an aftermarket radio...BUT the factory radio is in this? Any insight??

I'd look for a common relay, see if you can replicate symptoms by pulling it out, then replace it.

I would do the grounds.

It appears that I had my Actron Scanner plugged in at the time....... The issue has not re-occurred since it was unplugged..... I'm thinking the scanner being plugged in caused the issue.

Interesting!

Thanks for letting us know what fixed it!