| Subject: | Information on Navigation Radios that Have a Weak or No GPS Signal |
| Models: | 2007-2009 Cadillac Escalade Models |
| 2007-2009 Chevrolet Avalanche, Silverado, Suburban, Tahoe |
| 2007-2009 GMC Sierra, Yukon Models |
Some customers may comment on intermittent or no Global Positioning System (GPS) signal reception on the Navigation radio. The GPS signal reception icon on the map screen may have a red line through it.
This condition may be caused by aftermarket electronic devices such as radar detectors, cell phones, and MP3 players that may interfere with the GPS signal reception. Aftermarket window tinting or clear UV film applied to the windshield may also reduce
the GPS signal reception and cause the Navigation radio to function incorrectly.
Recommendations
Educate the customer on the GPS antenna location and the need to keep electronic devices away from it. The GPS antenna is located in the upper center of the Instrument Panel. Instruct the customer to move electronic devices away from the GPS antenna. It
may also be necessary to remove aftermarket films and tinting from the windshield.
Do not replace a Navigation radio that seems to have poor GPS signal reception without considering these possible causes of the concern. Refer to the No Global Positioning System (GPS) Reception diagnostic procedure in SI for more information.
