Function Diagram of M 70 Engine Management

1 Control unit - Electronic Motor Load regulation (EML) 2 Accelerator pedal 3 Control unit - Digital Motor Electronics (DME) 4 Hot wire air flow meter 5 Intake air temperature sensor 6 Fuel Injectors 7 Electric throttle assembly 8 Coolant temperature sensor 9 High tension distributor 10 Cylinder identification 11 Oxygen sensor 12 Reference/RPM sensor 13 Ignition coil 14 Relays (main, fuel pump, oxygen sensor heater) 15 Ignition switch 16 Battery 17 Diagnosis socket 18 AEGS control unit - automatic transmission 19 Instrument cluster 20 Evaporative purge valve
21 Carbon canister 22 Fuel pressure regulator 23 Fuel filter 24 Fuel pump 25 Fuel Tank
Electronic Motor Load regulation (EML) is employed for the first time. EML provides exact cylinder bank synchronization, idle speed control and cruise control operation. EML operation is achieved with the use of responsive electric throttle valves. For complete EML information see TRI 12 02 87 (2087).


Dual hot wire air flow meters assure rapid and precise load determination. Heated wire air mass meaasurement incorporates altitude and moisture compensation, thus a more exact air/fuel ratio can be maintained under all driving conditions. Since there are no moving parts, the new air flow meters are impervious to unfavorable mechanical tolerances or jamming.

NOTE:
The new airflow meter is flowbench calibrated at the factory and is maintenance-free. Attempted adjustments will render the unit unusable and, in such cases, warranty claims will not be accepted.
The major components which make up the M1.2 Motronic system are:

one (1) EML control unit* two (2) DME M1.2 control units two (2) Hot wire air flow meters two (2) Electric throttle valve assemblies* two (2) Heated oxygen sensors two (2) Evaporative venting valves two (2) Air inlet temperature sensors two (2) Engine coolant temperature sensors

As illustrated, there are two independent M1.2 systems which operate their respective cylinder banks and are precisely balanced by EML.

*Note: While Electronic Motor Load Regulation (EML) is a separate and distinct system, the inter-relationship of EML and M1.2 require that certain EML components also be considered as constituents of the M1.2 system.