Your GM Account is where you can see, manage and change your OnStar plan, and you’ll find plans and pricing info tailored to you. You can do things like add to your OnStar plan, switch to a different plan, find your vehicle mobile app information, see diagnostic information* and get customer support. You can even schedule and manage maintenance and service for your car. And if you’ve misplaced your Owner’s Manual, no worries, you’ll find an online version, plus some extra how-to info. To log in, you can use your GM Account, your OnStar account, your vehicle mobile app or your My GM Rewards.