Thanks, Brian.

I followed your instructions, it looks like I am in trouble! Here is what was reported:

Sensor Check:
Wheel Sensor: 0
GPS Status: GPS Malfunction
GPS Satellites: 00

GPS Version:
Receiver SW Vers. 0.0
Receiver SW Date: 99.99.99

Actually, the battery was replaced two months ago, and I had not used the Nav since then until three days ago. I think the car had to be "jumped" to get it started when the battery died in 15 degrees F. weather. Have I fried the computer? Can the GPS SW be reloaded?

Thanks.