Operation CHARM: Car repair manuals for everyone.

Introduction




The Electronic Throttle Control System (EML) regulates the operation of the throttle valve(s). The scope of EML design on BMW engines provides:

- Throttle valve positioning for optimum starting
- Precise idle speed regulation without the use of an external idle control valve/circuit
- Progressive throttle opening curves matched to the driving program (with EGS/AGS interface)
- Cruise control operation without additional control modules and linkages
- Automatic synchronization of the throttles (airflow balancing) for two independent banks, throughout the entire engine speed range (M701 S70, M73 engines only)
- Intake air volume control for ASC/DSC (Automatic Slip Control/Directional Stability Control) systems
- Maximum road speed limiting
- Emergency "Failsafe" operation in the event of component failures

The EML control module is a link in the total scope of Engine Management
Control. The EML is interfaced with other control modules to complete the
management system, which includes:

- ECM(s) - Except E46 (EML integrated in MS42.0 ECM)
- EGS/AGS
- ABS/ASC

The main components of the EML system are:

- Accelerator pedal position sensor (PWG)
- Accelerator pedal position sensor (driver's wish sensor - integrated in throttle housing, E46 MS42.0)
- Throttle valve assembly/assemblies with electronic control motor(s) - DK/MDK
- EML control module (MS42.0 ECM - E46)