2011 Chevrolet Volt Owner's Manual - Page 265

Infotainment System When the vehicle is not receiving signals from the satellites, a symbol appears on the map screen. See Navigation Symbols on page 7‑47. This system might not be available or interferences can occur if any of the following is true: . 7-75 Vehicle Positioning At times, the position of the vehicle on the map could be inaccurate due to one or more of the following reasons: . . . The vehicle changes directions more than once, or the vehicle is turning on a turn table in a parking lot. The vehicle is entering and/or exiting a parking lot, garage, or a lot with a roof. The GPS signal is not received. A roof carrier is installed on the vehicle. Tire chains have been installed. The tires are replaced or worn. The tire pressure for the tires is incorrect. This is the first navigation use after the map data is updated. The 12-volt battery is disconnected for several days. The vehicle is driving in heavy traffic where driving is at low speeds, and the vehicle is stopped and started repeatedly. . The road system has changed. The vehicle is driving on slippery road surfaces such as in sand, gravel, and/or snow. The vehicle is traveling on winding roads or long straight roads. Approaching a tall building or a large vehicle. The surface streets run parallel to a freeway. The vehicle has been transferred by a vehicle carrier or a ferry. The current position calibration is set incorrectly. The vehicle is traveling at high speed... Signals are obstructed by tall buildings, trees, large trucks, or a tunnel. Satellites are being repaired or improved. . . ... For more information if the GPS is not functioning properly, see "If the System Needs Service" and "Problems with Route Guidance." . . . . . . . .