Onstar Block Diagram
WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
| Callout | Component Name |
|---|---|
| DB | Serial Data - GMLAN Low Speed |
| DD | Serial Data - GMLAN High Speed |
| B24 | B24 Cellular Phone Microphone |
| C3 | C3 Telematics Communication Interface Control Module Battery |
| S51 | S51 Telematics Button Assembly |
| T4G | T4G Cellular Phone, Navigation, and Digital Radio Antenna |
| T4S | T4S Wireless Communication Antenna - Bluetooth |
| K73 | K73 Telematics Communication Interface Control Module |
| A11 | A11 Radio |
| X84 | X84 Data Link Connector |