Patent ID: 7905219

Claim:
A method of heating at least one injector of an engine comprising the steps: providing an engine control unit and an additional control device coupled between the engine control unit and the at least one injector and configured to control the operation of the at least one injector; the additional control device receiving an input pulse profile from the engine control unit; the additional control device adapting the received input pulse profile to generate output signals for activating the at least one injector in such a way that the at least one injector is heated, including: generating a first output pulse profile for activating the at least one injector during a first phase to empty a gas rail, which is connected to the at least one injector, the first output pulse profile defining a number of first electrical pulses, each first electrical pulse having a first pulse time period configured to activate the at least one injector to open the at least one injector a first amount, such that the first output pulse profile provides a metered emptying of the gas rail, and generating a second output pulse profile for activating the at least one injector, after the gas rail is emptied by application of the first output pulse profile, to heat the at least one injector during a second phase, the second output pulse profile defining a number of second electrical pulses, each second electrical pulse having a second pulse time period longer than the first pulse time period, to open the at least one injector a second amount greater than the first amount.