How to Reset the Engine Oil Life System

WARNING: This page is about a different car, the 2017 GMC Acadia. However, it is still accessible from the selected car via links, so may be relevant.

Using the DIC controls on the right side of the steering wheel, display REMAINING OIL LIFE on the DIC. When remaining oil life is low, the CHANGE ENGINE OIL SOON message will appear on the display.
Press SEL on the DIC controls and hold SEL down for a few seconds to clear the CHANGE ENGINE OIL SOON message and reset the oil life at 100%. Be careful not to reset the oil life display accidentally at any time other than after the oil is changed. It cannot be reset accurately until the next oil change.

The oil life system can also be reset as follows:

Turn the ignition on with the engine off.
Fully press and release the accelerator pedal three times within five seconds. If the CHANGE ENGINE OIL SOON message is not on, the system is reset.