GM Service Manual Online
For 1990-2009 cars only

Inappropriate route guidance may occur under any of the following conditions:

    â€¢ You have not turned onto the road indicated by the system.
    â€¢ Route guidance is not available for the next turn.
    â€¢ The route is not changed during automatic rerouting.
    â€¢ Plural names of places are displayed.
    â€¢ You are driving at high speeds, which may cause the automatic rerouting to operate more slowly.
    â€¢ The route prohibits the entry of a vehicle due to a regulation by time or season or any other regulation which may be given.
    â€¢ A route cannot be found.
    â€¢ A road is new, was recently changed or is not listed on the DVD. The route to the destination may not be shown. See Ordering Map DVDs .