Technical Bulletin (Car-Net Unresponsive - Verizon Telematics Service Interruptions and Outages):
When beginning diagnosis for customer concerns related to functionality of the Car-Net system, it is important to understand that the symptom(s) may not be related to any problem with the vehicle itself. If there are any problems with the AT&T 3G service and/or a service interruption or outage with the Verizon Telematics system, one or more Car-Net functions may be inoperative.
This document discusses the diagnosis, and potential remedy of the issue.