Method of operating an internal combustion engine in an engine warm-up phase

A method of operating an internal combustion engine during engine warm-up, said engine including a cylinder with a piston defining a combustion chamber and a fuel injection device for a direct injection of fuel into the combustion chamber, and further a coolant circuit and an exhaust gas recirculation device for re-circulating exhaust gas to the combustion chamber, said method comprising the steps of:

• injecting fuel into the combustion chamber of the internal combustion engine in a pilot injection, main injection and, selectively, a post-injection,
• operating the internal combustion engine in a heat-up phase as a function of a coolant temperature of the engine, wherein
• a center position of the combustion is moved in a heating mode in a late direction relative to a center position of the combustion in a normal engine operating mode, and
• in order to increase a generation and transfer of heat to the coolant during the heat-up phase, the fuel is injected during the pilot injection in the form of at least two distinct partial quantities.