System and method for detecting and counteracting diesel engine runaway

Method for detecting and counteracting a runaway condition in an operator controlled diesel engine system, said diesel engine system comprising:

• a diesel engine, an inlet for supplying combustion air to the diesel engine, an exhaust for relieving the diesel engine from exhaust gas, an exhaust gas recirculation system for selectively allowing exhaust gas from the exhaust to enter the inlet, and a first gas flow path actuator in the exhaust gas recirculation system;
• wherein the method comprises:
• detecting, with an engine control unit (ECU), an actual or potential engine runaway condition in the diesel engine system;
• and
• allowing an operator to effect stalling of the diesel engine in response to a detected actual or potential runaway condition by depriving the diesel engine of oxygen by opening the first gas flow path actuator for causing stalling of the diesel engine, said diesel engine system further comprising:
• a second gas flow path actuator in the exhaust, and enabling closing of the second gas flow path actuator in conjunction with opening of the first gas flow path actuator for contributing to stalling of the diesel engine,
• wherein depriving the diesel engine of oxygen is accomplished through:
• maximizing recirculation of exhaust gasses to the engine;
• and
• increasing pressure drop over the exhaust for a first predetermined period of time, and
• wherein the method comprises monitoring the diesel engine during, and after the first predetermined period of time for confirming if stalling of the engine has been accomplished, and further wherein the causing of stalling of the diesel engine is accomplished with the inlet substantially fully open.