In air intake systems with cooled exhaust gas recirculation, when leaks occur in the exhaust gas cooler, cooling liquid can enter the intake air. This can damage the engine even before the leak is detected via an indication of coolant loss. Detection of such a leak may prevent the potential damage.
Previously, a leak in the cooling system has been detected exclusively by the fall in level of coolant in the expansion tank. For this, systems are used which monitor the level in the expansion tank or in the radiator via electrodes.