GMC Sierra 2021 Getting To Know Your Manual
![GMC Sierra 2021 manual cover](/images/NLoDMpKOPUxZwZaqGDQJxNUe/thumbs/thumb175x175.webp)
To reset the oil life monitor, turn the ignition to the "On" position without starting the engine. Use the DIC controls on the steering wheel to navigate to the "Oil Life" menu. Press the "Check" button and hold it until the oil life percentage resets to 100%.
The recommended engine oil for the 2021 GMC Sierra is SAE 0W-20 for the 5.3L and 6.2L engines and SAE 5W-30 for the 4.3L engine. Always use oil that meets the GM dexos1® specification.
To improve fuel efficiency, keep tires properly inflated, reduce excess weight from the vehicle, maintain a steady speed, and perform regular maintenance such as air filter and spark plug replacements.
The towing capacity of the 2021 GMC Sierra varies by configuration. The maximum towing capacity is 11,800 pounds for the 5.3L V8 engine with the Max Trailering Package. Refer to your owner's manual for specific configurations.
To connect your phone via Bluetooth, go to the "Settings" menu on the infotainment system, select "Bluetooth," and ensure it's turned on. Then, on your phone, enable Bluetooth and select "GMC Sierra" from the list of available devices. Confirm the pairing code when prompted.
If the check engine light comes on, ensure the gas cap is tight as a loose cap can trigger the light. If the light remains on, consider using an OBD-II scanner to diagnose the issue or take the vehicle to a qualified mechanic for evaluation.
It is recommended to inspect the air filter every 15,000 miles and replace it if it appears dirty. Under normal driving conditions, replace the air filter every 30,000 miles.
To update the navigation system, visit the GMC Navigation website and download available updates to a USB drive. Insert the USB drive into the vehicle's USB port and follow the on-screen instructions to install the update.
Common causes of battery drain include leaving lights on, faulty alternator, parasitic drain from electronic devices, and old or failing battery. It's important to check these factors if you experience battery issues.
To enable trailering assist features, access the trailering app on the infotainment system. Configure your trailer profile, and activate features like Trailer Light Test and Trailer Brake Gain Adjustment through the app.