Engine Control Module: Description and Operation

This system is used on 911 (exc. turbo), 924 and 944 models. The system is controlled by the Digital Motor Electronics (DME) system, which also controls ignition timing.
This system is electronically controlled and operated by the incoming air flow. This system maintains the air/fuel ratio as close as possible to ideal. The heart of this system is the (DME) Electronic Control Unit (ECU). The ECU (DME) receives signals from various sensors, such as the oxygen sensor, and is programmed to interpret these signals and constantly adjust the air/fuel ratio and keep exhaust emissions to a minimum. The ECU (DME) also controls ignition timing.