The document discusses reasons why a Volvo XC60's check engine light may come on and how to reset it. Common causes for the check engine light include a faulty gas cap, problematic catalytic converter, failing ignition system, disproportionate air-fuel ratio, and faulty sensors. To reset the check engine light, one can use an OBD-II scanner to retrieve error codes and diagnose issues, or disconnect the car battery for a moment to erase error codes and turn off the light.