Many Engine management systems follow an all-in-one approach. All engine functions (spark, fuel, emissions) are monitored and controlled by a single central control unit. Unlike these systems, the Bosch LH 2.4/3.1 system features separate ignition and fuel control units. Rather than working entirely separately, these two systems are actually interconnected. Shared inputs and outputs are passed between both units. What follows is a brief description of some of the LH system’s key components and functions.