Pioneer AVIC-505 Owner's Manual page 146

When: if the GPS aerial fails to pick up signals from GPS satellites.
What to do: check that the GPS aerial is properly installed and move it to a suitable
position if required.
When: if the built-in gyrosensor does not receive vehicle speed pulse.
What to do: consult with your Pioneer dealer.
When: if the distance to the destination is too far and cannot be set.
What to do: change the destination to a location that is closer and divide up the route.
When: if there is no appropriate detour route using or avoiding motorways.
What to do: change the conditions and try setting the route again.
When: if you try to set more than two destinations.
What to do: add the next destination after arriving at your first destination.
When: if route setting cannot avoid a specified area to be avoided.
What to do: choose whether or not to try setting a route through the area.
When: when you choose to reroute.
What to do: wait until rerouting is completed.
When: when rerouting is complete.
What to do: begin driving when guidance begins.
When: if you enter a name of five characters or less for a registered location or a
listing in the Destination history.
What to do: use a name with more than five characters.