OnStar uses a Telematics Control Module manufactured by LG, model TTA20ANEBN . it controls the signals for 4gLTE as well as GPS. Source: https://imgur.com/gallery/n00QKnH From Amazon order the following: 1x Z Female to SMA Female antenna cable 1x SMA male 50 ohm terminator Assemble and use a small zip tie to package it nicely. The terminator is necessary to completely block out the cellular signal, with the antenna unplugged OnStar did not connect at home, but while at work the OnStar light was sometimes green. With the terminator connected it is always red and disabled. Note: disabling OnStar is in response to the write up from Mozilla here: https://foundation.mozilla.org/en/privacynotincluded/articles/its-official-cars-are-the-worst-product-category-we-have-ever-reviewed-for-privacy/ Open the glove box all the way, in order to do this the damper needs to be removed. Simply slide it to the right to disconnect it from the glove box. Note: this is the right side of the glove box, when the glove box is opened. The OnStar module is behind the infotainment display, with a flashlight and cellphone camera you can see what it looks like. The purple and brown plugs are what we’re interested in. The purple plug is for the cellular antenna, and the brown plug is for the GPS antenna. We only need to unplug the closer purple plug. Note: it is easier to access this connector with your hand between the rear of the dash and in front of the aluminum bar pictured in the left of this image (see next picture) this angle is best for pictures. To unplug this connector you need a small screwdriver to slide the red lock backward. It only moves about 3MM or 1/8†(see in the picture after the next one to see what it look like), but one the lock is moved back the plug can be removed by pressing the top rear of the purple housing down and pulling back. Side view of OnStar module. This is where it is easier to reach into and access the connector. View with antenna terminator installed. I just let the cellular antenna connector hang out where I left it. Note: the red locking tab is pulled back to allow the unlocking button to be pressed in. To reverse the modification simple remove the terminator and reinstall the purple antenna connector. After turning on the car and driving around a bit OnStar is no longer connecting to its network (also be sure to disable the WiFi connection to your home too if you set that up). The GPS and compass work fine, so does the location feature for charging. Making and receiving calls over Bluetooth works perfectly too. No OnStar, just a red light. I may disconnect the cable to the OnStar buttons in the future so I don't have to look at the red light, or I may not, it doesn't bother me. Compass etc still working, no warning lights or error lights. ================= ALTERNATIVE: https://www.chevybolt.org/threads/remove-mobile-data-chip.33237/ I pulled the fuse on my 2023 EUV and did not lose bluetooth microphone functionality. They appear to have done the wiring differently, as its on a different header (F02) than previous model years. I have not noticed any adverse effects yet (other than losing mobile data dependent features), but I'll give it a week and report back. Instrument Panel Fuse Box Fuse Box Location The instrument panel fuse block is on the left side of the instrument panel. left below steering wheel. To access the fuses, open the fuse panel door by pulling out. Assignment of the fuses in the instrument panel № Usage F01 Video Processing Module F02 2022: Indicator Light Solar Sensor 2023: Telematics Control Platform (OnStar) F03 Side Blind Zone Alert F04 Passive Entry, Passive Start F05 Central Gateway Module F06 Body Control Module 4 F07 Body Control Module 3 F08 Body Control Module 2 F09 Body Control Module 1 F10 Sunroof F11 Amplifier F12 Body Control Module 8 F13 Data Link Connector F14 Parking Assist F15 Headlamp (left) F16 Single Power Inverter Module 1 F17 Body Control Module 6 F18 Body Control Module 5 F19 External Object Calculation Module 2A F20 Advanced Driver Assist Map Module F21 Driver Monitoring System F22 - F23 USB F24 Wireless Charging Module F25 Reflected LED Alert Display F26 Heated Steering Wheel F27 Central Gateway Module 2 F28 Instrument Cluster 2 F29 POLICE_SSV F30 - F31 2022: Telemetics Control Platform (OnStar) F32 - F33 Heating, Ventilation, and Air Conditioning Module F34 HVAC Display/lntegrated Center Stack Display F35 Instrument Cluster 1 F36 Center Stack Module F37 - F38 - F39 - F40 2023: Indicator Light Solar Sensor F41 - F42 - F43 Body Control Module 7 F44 Sensing and Diagnostic Module F45 Front Camera Module F46 Vehicle Integration Control Module F47 Single Power Inverter Module 2 F48 Headlamp (right) F49 Auxiliary Jack F50 Steering Wheel Controls F51 - F52 - F5B Auxiliary Power Outlet F54 - F55 Logistic F56 POLICE_SSV Relays F57 POLICE_SSV F58 Logistics Relay F59 - F60 Accessory / Retained Accessory Power Relay