Diagnostic Aids
WARNING: This page is about a different car, the 2008 Isuzu Ascender, 2008 GMC Envoy, and 2008 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The customer concern may have been due to a lack of cellular service in a given area. A failure in the National Cellular Network infrastructure that has since been corrected.