Navigation Radio GPS Is Inoperative Or Inaccurate - keywords antenna coax inaccurate inop inoperative nav navigation nogps onstar radio vcim
| Subject: | Navigation Radio GPS is inoperative or inaccurate |
| Models: | 2007 - 2008 full size trucks and utilities with navigation radio |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
The navigation radio will have no or inaccurate GPS. Dealers may have replaced or re-routed the GPS antenna for the navigation radio with no change. Some dealers have found that by disconnecting the VCIM the concern is eliminated.
Recommendation/Instructions:
DO NOT REPLACE the OnStar® VCIM for this condition.
The GPS antenna for the navigation radio is located in the center area of the dashboard just forward and above the navigation radio, VCIM and HVAC control head. The location of the antenna and the potential electromagnetic interference from the modules in the dash area may cause this concern. TAC and engineering have found that by placing a small metal plate below the GPS antenna assembly in the dash for the Navigation Radio the condition will be eliminated. (see photos below)
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
