I'm having the exact same problem. About three weeks ago I had an AVIC-Z150BH unit professionally installed in my Porsche Cayman. I am very disappointed with the performance of the GPS unit which: (1) regularly takes improper routes that include local roads instead of highways: (2) goes longer distances to reach my destination, often requiring me to make "U" turns; and, (3) insists on returning to an improper route instead of performing a recalculation, despite the fact that I've ignored its guidance and continued on the correct route. I've verified that the unit has its preference on"faster" rather that "shorter", but the fact is that the route calculated by the GPS is neither "faster" nor "shorter"; it is simply incorrect. I've been back to the installer, who is unable to find anything wrong with the unit or the installation. Considering the expense of this unit I'm very disappointed in its poor performance.
Wrong route/directions
in Problems/Troubleshooting
Posted
I'm having the exact same problem. About three weeks ago I had an AVIC-Z150BH unit professionally installed in my Porsche Cayman. I am very disappointed with the performance of the GPS unit which: (1) regularly takes improper routes that include local roads instead of highways: (2) goes longer distances to reach my destination, often requiring me to make "U" turns; and, (3) insists on returning to an improper route instead of performing a recalculation, despite the fact that I've ignored its guidance and continued on the correct route. I've verified that the unit has its preference on"faster" rather that "shorter", but the fact is that the route calculated by the GPS is neither "faster" nor "shorter"; it is simply incorrect. I've been back to the installer, who is unable to find anything wrong with the unit or the installation. Considering the expense of this unit I'm very disappointed in its poor performance.