Electronic Engine Control System for Gasoline Engines for LEV and ULEV Standards

The center of the Siemens LEV/ULEV-solution is an electronic control unit with a high potential processor, which fulfills all requirements for high calculation accuracy and OBDII-diagnostics. Several new functions were designed on this platform to make sure that the vehicle emissions are low in every operating condition and over the vehicle lifetime. The paper describes the emission benefits of selected new functions and components.

• Improved fuel preparation with air assisted injectors decreases the engine out emissions and allows a higher spark retardation and a leaner engine mixture without driveability degradation in the catalyst heat up phase.
• A transient function includes a physical intake manifold model for the calculation of the air amount which enters the cylinder and also a 2nd order wall wetting compensation model.
• An electrical heated catalyst (EHC) combined with secondary air injection and a multi brick cascade catalyst system.
• Alternatively, a burner heated catalyst (BHC), which has a higher heating power and better efficiency than the EHC.