Electronic throttle control is an engine technology that uses electric signals as opposed to a direct cable to
control the throttle of the engine. Electronic throttle control is also known as drive by wire as it forms an integral
part of an entire drive by wire system.
There are several reasons for an electronic throttle control system in an engine.
- It cancels the need for a direct cable and any other mechanical parts that would be needed with the cable thereby
reducing the amount of moving parts needed for the engine to function.
- It makes it easier for external electrical systems which will be discussed to be integrated into the engine.
The engine management system then sends an electronic signal to a motor which is used to adjust the position of the
throttle. This electronic signal is an instruction of how far to open the throttle.
How it works is by using a sensor to determine the pedal position.
As your foot presses on the accelerator
pedal the sensor continuously measures for far the pedal has moved from its original position and sends an electrical signal
to the engine management system.
Older versions of electronic throttle control may have another ECU
dedicated to it.
If the pedal is pressed halfway down the signal would indicate to the engine management system that it is pressed
halfway down in a similar manner to if there was the conventional cable and it would only be pulled half of the distance
to open the throttle.
There is also a throttle position sensor to send information to the engine management system to let it know that the
throttle is in the correct position in relation the data sent by the engine management system.
The information from the pedal position sensor is used together with information from other sensors but the pedal
position sensor usually remains as the main source of information unless some system like these listed below is controlling
Electronic throttle control operates with lightening speed and precision and many drivers may not be able to tell that
their vehicle uses drive by wire technologies instead of cables for throttle control.
- Features like cruise control and crawl control can
be easily facilitated. These systems operate the engine with no input from the driver once they are switched on.
- Safety systems such as traction control and stability
control. These are systems that temporarily take control of the engine while the driver may or may not be pressing the
- Features like terrain response and selec terrain
that operate the engine together with input from the driver once they are switched on.
There are also fail safe measures built into these systems to prevent issues such as external waves interfering with the
electrical signal, the system unnecessarily controlling the engine irrespective of the driver's input or items being stuck in the
The vehicles are tested to ensure these issues never take place but should any issues occur it will provide the safest
alternative which may be to turn off the engine in some cases.