The EML is the electronic throttle control. The throttle body is controlled by the engine computer (DME in BMWspeak). The gas pedal assembly has 2 very closely matched potentiometers. A potentiometer is a variable resistor. The DME is constantly checking the resistance of both potentiometers to see if there’s a change. The DME uses the resistance of the potentiometers and all of the sensor data (MAF voltage, engine temperature, etc.) to determine the change in the throttle body flap’s opening. I believe the throttle body has an electronic part that tell the DME the position of the flap. When there’s a mismatch in this system such as an error in the throttle body the EML light is enabled.
The first step in diagnosing a problem is to scan the DME for codes.
The first step in diagnosing a problem is to scan the DME for codes.
