I own a 2004 C5 Vette with 17,000 miles. The

I own a 2004 C5 Vette with 17,000 miles. The Headsup display freezes with a disfunctioning situation where the MPH doesn't show up in the 6 o'clock display. If I turn it off and on several times, the display will reboot and while stopped it will show O mph -then it will read the mph on my speedomter. When I restart the Vette, the Headsup display will not work. This just started to be a constant problem. Many thanks.
FJ