System Overview

Digital Motor Electronics (DME M3.1, 6-cylinder M 50):

System Diagram:

System Diagram:

NOTES: The following description refers to the digital motor electronics system DME M3.1 for the 6-cylinder, 4-valve engine M 50 (2.5 L).

New Features:

New features compared to the digital motor electronics DME M1.3 for the 6-cylinder engines M 20 and M 30.

PURPOSE
The Digital Motor Electronic system (DME) 3.1, provides precise control of fuel injection and ignition systems to ensure optimum performance and strict emissions compliance.

OPERATION
Various engine sensors and other systems (i.e.. air conditioning, auto transmission etc.) supply the DME control unit with operating information. The DME control unit processes this information and sends control signals to adjust injector pulse width, ignition timing and influence other important systems and components.

The DME system assumes functions listed below:
^ Injection control
^ Ignition timing (angle) control
^ Ignition control with static high tension distribution
^ Dwell angle control
^ Cold start control
^ Maximum speed control
^ Idle speed control
^ Acceleration enrichment
^ Dynamic torque deceleration fuel cut-out
^ Adaptive emission (lambda) control
^ Adaptive fuel evaporation control
^ Adaptive idle speed control
^ Characteristic map switchover for EH transmission
^ Limited (emergency) operation control
^ Relay controls
^ A/C compressor cut-out
^ Protection functions for catalytic converter and engine
^ Self-diagnosis with defect code storage
^ Drive-away protection

The system can also operate in conjunction with other systems such as:
^ Electronic transmission control (EGS)
^ Instrument cluster (K)
^ Antitheft system (DWA)
^ On-board computer (BC)

Input Signals:

Input Signals:

Input Signals:

Output Signals:

Output Signals: