Mazda 3 Owners Manual: Fuel-Filler Lid and Cap
CAUTION If the check fuel cap warning light illuminates, the fuel-fi ller cap may not be properly installed. If the warning light illuminates, park your vehicle safely off the right-of-way, remove the fuel-fi ller cap and reinstall it correctly.
After the cap has been correctly installed, the fuel cap warning light may continue to illuminate until a number of driving cycles have been completed. A drive cycle consists of starting the engine (after four or more hours with the engine off ) and driving the vehicle on city and highway roads.
Continuing to drive with the check fuel cap warning light illuminated could cause the check engine light to illuminate as well.