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With the available In-Vehicle Trailering App1 and the myGMC® app,2 you can activate the Trailer Light Sequence Test, which runs a lighting sequence of essential lights used in trailering. It only takes one person to conveniently activate this sequence and simply walk around the vehicle to inspect the lights.

1. App functionality and features vary with vehicle equipment and trim level. Data connection may be required. Some features require active service plan and working electrical system. Terms and limitations apply.
2. Available on select Apple and Android devices. Service availability, features and functionality are subject to limitations and vary by vehicle, device and the plan in which you are enrolled. Device data connection required. Visit for more details.