US Patent RE39845 Maintenance alert system for heavy-duty trucks

A real-time maintenance alert system and method for use in a heavy-duty truck having an engine controller with memory are provided. The system includes a sensor operative to indicate an engine condition from the group consisting of: oil filter restriction, air filter restriction, fuel filter restriction, oil level, and coolant reserve tank fluid level. Control logic at the engine controller processes the sensor signal to determine a real-time fault condition, when appropriate.