Removal Procedure
Important: The vehicle interface unit (VIU) has a specific set of unique numbers that tie the module to each vehicle. These numbers, the 10-digit station identification and the 11-digit electronic serial number, are used by the
National Cellular Network and OnStar® to identify the specific vehicle. Because these numbers are tied to the vehicle identification number of the vehicle, you must never exchange these parts with those of another vehicle.
- Remove the top cover of the body side trim panel on the right side of the vehicle to expose the VCU/VIU assembly.
- Remove the 2 nuts (1) and lift the VCU/VIU assembly up and out of the vehicle.
- Disconnect the cellular antenna coaxial cable (2) and electrical connector (6) from the VCU (7).
- Disconnect the global position sensor (GPS) cable connector (4) and electrical connector (3) from the VCU/VIU assembly
- Remove the 4 screws that attach the VIU to the assembly bracket.
- Remove the VIU (1) from the vehicle.
- The old VIU must be returned for core credit.
Installation Procedure
- Record the 10-digit STID number from the label on the VIU module.
- Install the VIU (4) to the VCU/VIU assembly mounting bracket.
Notice: Refer to Fastener Notice in the Preface section.
- Install the 4 screws that attach the VIU to the assembly bracket.
Tighten
Tighten the screws to 2 N·m (18 lb in).
- Reconnect the cellular antenna coaxial cable (2) and electrical connector (6) to the VCU.
- Reconnect the GPS cable connector (4) and the electrical connector (3) to the VCU/VIU assembly.
- Install the VCU/VIU assembly to the vehicle. Ensure that the lower arm (3) of the mounting bracket
is inserted into the slot (2) provided in the body sheet metal.
- Install the VCU/VIU assembly to the vehicle using the 2 nuts (1).
Tighten
Tighten the nuts to 10 N·m (89 lb in).
- Install the top cover of the body side trim panel to cover the VCU/VIU assembly.
Important: After replacing the VIU, you must reconfigure the OnStar® system. Failure to reconfigure the system will result in an additional customer visit for repair.
- Reconfigure the OnStar® system. Refer to
OnStar Reconfiguration
.