Patent attributes
A method for operating a liquid coolant circuit of an internal combustion engine is described in which the coolant circuit contains an integrated EGR cooler such that the cooling system has a single circuit with two operational modes. The method includes a controller that can switch between operational modes to enable delivery of coolant to the EGR cooler when the flow of coolant through the block cooling circuit is blocked. In the second operational mode, the method also includes using an auxiliary pump to pass coolant to the EGR cooler while bypassing the main coolant pump, which can occur by adjusting the flow of coolant through the circuit so the flow through a bypass line is reversed relative to the inherent forward direction of flow in the bypass line during the first operational mode.