2009 Chevrolet Silverado 2500 HD Extended Cab Owner's Manual - Page 328

XM™ Satellite Radio Service XM Satellite Radio Service gives digital radio reception from coast-to-coast in the 48 contiguous United States, and in Canada. Just as with FM, tall buildings or hills can interfere with satellite radio signals, causing the sound to fade in and out. In addition, traveling or standing under heavy foliage, bridges, garages, or tunnels may cause loss of the XM signal for a period of time. Fixed Mast Antenna The fixed mast antenna can withstand most car washes without being damaged as long as it is securely attached to the base. If the mast becomes slightly bent, straighten it out by hand. If the mast is badly bent, replace it. Occasionally check to make sure the antenna is tightened to its base. If tightening is required, tighten by hand until fully seated plus one quarter turn. Cellular Phone Usage Cellular phone usage may cause interference with the vehicle's radio. This interference may occur when making or receiving phone calls, charging the phone's battery, or simply having the phone on. This interference causes an increased level of static while listening to the radio. If static is received while listening to the radio, unplug the cellular phone and turn it off. XM™ Satellite Radio Antenna System The XM Satellite Radio antenna is located on the roof of the vehicle. Keep the antenna clear of obstructions for clear radio reception. If the vehicle has a sunroof, the performance of the XM system may be affected if the sunroof is open. 3-142