OnStar Corporation is a subsidiary of General Motors that provides subscription-based communications, in-vehicle security, emergency services, hands-free calling, turn-by-turn navigation, and remote diagnostics systems throughout the United States, Canada, China, Mexico, Europe, Brazil, and Argentina.
A similar service is known as "Vauxhall/Opel OnStar" in western Europe and "ChevyStar" in Latin American markets (except in Mexico, Brazil and Argentina). In September 2011 the president of OnStar stated that the service had more than six million customers. On May 9, 2018, Vauxhall Motors announced that Vauxhall OnStar, alongside Opel OnStar services, would cease to operate after December 31, 2020, following Groupe PSA's purchase of Vauxhall Motors and Opel from General Motors.
A new aftermarket interior rear-view mirror with a built-in OnStar module, branded as OnStar FMV, became publicly available on July 24, 2011. It provides some of the features an OEM system has, such as Automatic Crash Response, Stolen Vehicle Tracking, Turn-by-Turn Navigation, and Roadside Assistance.
Ford had "a similar system" named RESCU and it was introduced with Ford's 1996 Lincoln Continental. Ford's service is now SYNC.
OnStar was formed in 1996 as a collaboration between GM, Electronic Data Systems and Hughes Electronics Corporation. Each of the founding companies brought a specific area of expertise to the enterprise: GM brought vehicle design and integration and a distribution system of millions of vehicles, EDS brought much of the systems development and information management and customer service technologies, while Hughes (creators of DirecTV) contributed communications and satellite technology and automotive electronics.
In 1996, GM North America Operations President Rick Wagoner officially launched OnStar at the Chicago Auto Show. OnStar delivered its first product and service to the market in 11 months, in the fall of 1996 for model-year 1997 Cadillac DeVille, Cadillac Seville, and Cadillac Eldorado models. From 2002 to 2006, OnStar service was available on vehicles produced by Acura, Audi, Isuzu, Subaru, and Volkswagen through a licensing agreement.
In April 2006, GM notified approximately 500,000 of their OnStar customers who had analog service that their service would be terminated effective December 31, 2007, because starting February 18, 2008 the Federal Communications Commission (FCC) would no longer require US cell phone systems to operate in analog mode. Customers who purchased a prepaid, non-refundable, non-transferable 1-year OnStar Safe & Sound subscription were scheduled to receive an equipment upgrade. If the vehicle is from the 2003, 2004, or 2005 model year, an adapter costing approximately US$200 (includes a one-year subscription) can be installed at the customer's expense. If it is older, it will simply no longer be usable. A law firm in Pennsylvania representing some of the affected customers sought to have a class certified for a class-action lawsuit for damages claimed in the cancellation of OnStar service.
On December 19, 2011, GM said OnStar would join with Verizon Wireless to offer video chat and streaming content to automobile passengers.
Since 2014 OnStar offers LTE Wi-Fi service on select GM cars.
Starting June 14, 2021, the OnStar Guardian app was made available to any driver in the United States or Canada. The Guardian app uses sensors in the phone, such as the accelerometer and the GPS receiver, to provide some traditional OnStar services (e.g., automatic crash notification), regardless of the vehicle in which the user is riding.
The Guardian app also serves as the user interface, via Bluetooth, to the OnStar Link plug-in device, if it is installed. OnStar Link is a miniature GPS receiver and 4G LTE IoT interface that plugs into the vehicle's OBD-II connector. It can provide most traditional OnStar services, including a WiFi hotspot (additional data plan required), though not Stolen Vehicle Slowdown, Hands-Free Calling, Turn-by-Turn Navigation, or Send-to-Navigation. Voice communication with an OnStar Advisor requires a Bluetooth-paired cell phone.
In September 2021, GM notified owners of certain pre-2015 model-year vehicles in the United States that their factory-installed OnStar equipment will become obsolete and non-functional after December 2022. These vehicles use Verizon Wireless's 2G/3G CDMA network for communication, and Verizon has announced plans to sunset this network. Unlike GM's remedy under similar circumstances for Canadian customers, where the vehicle hardware was updated, customers in the United States will be provided an OnStar Link plug-in at no additional charge.