Vielleicht hast Du ja noch andere Warnmeldungen. Eine Möglichkeit wäre z.B diese:
Diesel Exhaust Fluid (DEF) Warning Messages
Your vehicle will begin displaying warning messages when the DEF level reaches a driving range of approximately 500 miles (800 km). If the following warning message sequence is ignored, your vehicle may not restart unless DEF is added with in the displayed mileage
shown in the EVIC message.