Damaged GPS Antenna Jumper During OnStar Digital Upgrade - keywords antenna coax connector damage DTC fit GPS jumper OnStar VCIM

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

When replacing the Vehicle Communications Interface Module (VCIM), it is important to follow the service procedure found in the Service Manual. The GPS antenna coax jumper cable can be broken if the procedure is not followed. The GPS antenna coax jumper cable connector is clipped to the cross car brace. The short length of the jumper from the connector to the VCIM does not allow the VCIM mounting bracket to be pulled back very far before breaking the terminal where it connects to the VCIM. The VCIM must be serviced by removing the rear seat and not from the trunk.

The VCIM is attached to the mounting bracket by a single large retaining tab. It slides out of the bracket after the tab is released. The GPS antenna coax jumper cable can be disconnected after the VCIM is removed from the bracket. In the event that the GPS connector on the on the GEN 4 VCIM is broken off during removal it will become lodged in the GPS jumper connector and cannot be removed. It is not necessary to replace the stock GPS jumper in order to complete the installation of the GEN 6 VCIM.

Note: The following process is only to be used in the event that the short GPS jumper from the digital upgrade kit cannot be connected to the stock GPS jumper.

The GPS antenna itself is located in the trunk on the rear package shelf. In order to access the antenna the rear seat should already have been removed as part of the VCIM replacement. The package shelf cover should also be removed. The GPS antenna cable has extra length coiled on the package shelf. Gently remove the retainer clips holding the cable in place and remove just enough length to reach the VCIM. Remove the white retainer cover from the GPS cable and discard. The GPS cable end will then connect directly to the GEN 6 VCIM.

Note: There is enough tension on the connector to hold the cable to the VCIM without a need for the blue colored lock connector found on the digital upgrade connector.

Reconnect the cable retainer clips where needed and reinstall the package shelf cover. Finally complete the VCIM installation as per instructions in service information.

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.