Global Positioning System (GPS) Limitations

Global Positioning System (GPS) Limitations 

The GPS cannot detect the vehicle's position or elevation during the following instances:

• For the first 5 to 10 minutes after reconnecting the battery (this process can take as long as 45 minutes).
• When the satellite signals are blocked by tall buildings, mountains, tunnels, large trees, inside parking structures or large trucks.
• When the GPS antenna is blocked by metallic window tinting or by an object placed above it in the vehicle. The GPS antenna requires a clear unobstructed view of the sky.
• When there is no satellite signal output (signal output is sometimes stopped for satellite servicing).
• When the satellite signals are blocked by the operation of some electronic aftermarket accessories including, but not limited to non-OEM in-dash entertainment units (amp, CD players/changers, radar detectors, theft recovery systems, etc.) and cell phones placed near the navigation system.

The accuracy of the GPS is reduced during these instances:

• Metallic window tinting above the GPS antenna.
• When only three or less satellite signals are received (Four satellite signals are required for accurate positioning).
• When driving near high tension power lines.
• When the satellite signals are blocked by the operation of some electronic aftermarket accessories including, but not limited to non-OEM in-dash entertainment units (amp, CD players/changers, radar detectors, theft recovery systems, etc.) and cell phones placed near the navigation system.
• When the satellite control centers are experiencing problems.