Abstract: Heating, ventilation and air conditioning systems having modular components are described.

Abstract: A method for determining an opening behavior of a combustion engine fuel injector having a coil drive includes: applying to a coil of the coil drive an electrical test excitation that is weaker than an electrical standard excitation applied to the coil during normal operation of the engine, such that an opening position of the fuel injector is achieved at a point at which the coil drive is not in magnetic saturation; measuring the chronological progression of an electrical variable of the coil; determining a first point in time at which the fuel injector reaches its opening position under the influence of the electrical test excitation, based on the measured chronological progression of the electrical variable, and determining a second point in time at which the fuel injector would reach its opening position under the influence of the electrical standard excitation, based on the determined first point in time.

Abstract: A method for determining an opening behavior of a combustion engine fuel injector having a coil drive includes: applying to a coil of the coil drive an electrical test excitation that is weaker than an electrical standard excitation applied to the coil during normal operation of the engine, such that an opening position of the fuel injector is achieved at a point at which the coil drive is not in magnetic saturation; measuring the chronological progression of an electrical variable of the coil; determining a first point in time at which the fuel injector reaches its opening position under the influence of the electrical test excitation, based on the measured chronological progression of the electrical variable, and determining a second point in time at which the fuel injector would reach its opening position under the influence of the electrical standard excitation, based on the determined first point in time.

Abstract: The activation of a swirl control valve which is seated downstream of a throttle valve in the intake tract of an internal combustion engine is diagnosed. The swirl control valve is activated by a specific adjustment travel within a supercritical operating range of the intake pipe pressure in the intake tract downstream of the throttle valve. If a specific jump in pressure that is dependent on the adjustment travel does not take place in the intake tract downstream of the throttle valve, a defect in the actuation of the swirl control valve is diagnosed.

Abstract: The activation of a swirl control valve which is seated downstream of a throttle valve in the intake tract of an internal combustion engine is diagnosed. The swirl control valve is activated by a specific adjustment travel within a supercritical operating range of the intake pipe pressure in the intake tract downstream of the throttle valve. If a specific jump in pressure that is dependent on the adjustment travel does not take place in the intake tract downstream of the throttle valve, a defect in the actuation of the swirl control valve is diagnosed.