Exhaust System Emission Control Urea Injection System (def) problems of the 2016 Land Rover Range Rover Sport

The contact owns a 2016 Land Rover Range Rover Sport. The contact stated while driving at an undisclosed speed, the message "def quality error no engine restarts in 250 miles" displayed, and the vehicle shut off. The vehicle was towed to the dealer, who flushed and refilled the diesel exhaust fluid (def) system, but the failure persisted. The vehicle was then taken to an independent mechanic, who replaced the injectors, updated the pcm, cleaned the filter, and flushed and refilled the def system. The failure recurred, and the vehicle was taken back to the independent mechanic, who removed suds from the intake manifold, replaced the valve covers, and flushed and refilled the def system for the third time. The contact stated that the failure persisted. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was 115,735.