If you are traveling in or to Canada and you cross theregional border, the only map scale views availableare 4 mi, 8 mi, 31 mi, and 128 mi (8 km, 16 km, 64 kmand 256 km). Change the selected search arearegion when you get closer to the area you are travelingto. See “Setting the Search Area” underMaps onpage 2-30 for more information.Remote Keyless Entry SystemWhen you insert the key in the ignition, Driver 1 orDriver 2 will be displayed on the screen. A message willnot appear on the screen if the driver is unknown.The number on the back of the RKE transmittercorresponds to driver 1 or driver 2. The navigationsystem can store memory points for drivers 1 and 2individually. See “Remote Keyless Entry Transmitter” inSection 2 of your vehicle’s owner manual for moreinformation.OnStar ® SystemWhen using the OnStar® system, the audio system willbe muted and the navigation voice prompts will bedisabled during the call. The volume of the OnStar® callcan be adjusted by using the steering wheel volumecontrols. See “Audio Steering Wheel Controls” and“OnStar® System” in your vehicle’s owner manual formore information.Global Positioning System (GPS)The navigation system determines the position of yourvehicle by using satellite signals, various vehicle signals,and map data.The Global Positioning System (GPS) locates thecurrent position of your vehicle using signals sent by theUnited States Department of Defense GPS satellites.While your vehicle is receiving signals from thesesatellites, the GPS symbol will not appear on the mapscreen. SeeSymbols on page 2-33 for more informationon the GPS symbol.However, at times, other interferences such as thesatellite condition, road configuration, the condition ofthe vehicle, and/or other circumstances can interferewith the system’s ability to determine the accurateposition of the vehicle. This is when the GPS symbolwill appear on the map screen.This system may not be available/or interferences mayoccur if any of the following are true:• Signal are obstructed by tall buildings, large trucks,or a tunnels.• Satellites are being repaired or improved.• Objects are located on the rear shelf.• After-market glass tinting has been applied to thevehicle’s windows.2-39