Accelerator pedal position sensors indicates the position of the accelerator on vehicle models with electronic throttle control. Accelerator pedal sensor is basically a throttle position sensor (TPS) with a pedal attached. The accelerator pedal sensor is part of the accelerator pedal. The accelerator pedal sensors are mostly used in “drive by wire” systems. The accelerator pedal module converts the driver’s accelerator pedal effort to an electric signal, and sends the signal to the engine ECU, which controls engine power and acceleration. Accelerator pedal sensors are used in electronic throttle control (ETC), an automobile technology which severs the mechanical link between the accelerator pedal and the throttle. The same accelerator pedal sensors also used as brake pedal sensors.

Electronic Throttle Control (ETC) System

In electronic throttle control (ETC) equipped vehicles, electronic control unit (ECU) determines the required throttle position by calculations from data measured by accelerator pedal position sensors, engine speed sensors, vehicle speed sensors etc. The electric motor within the ETC is then driven to the required position via a closed-loop control algorithm within the ECU.

Electronic Throttle Control (ETC) System facilitates the integration of features such as cruise control, traction control, stability control, and precrash systems and others that require torque management, since the throttle can be moved irrespective of the position of the driver’s accelerator pedal. And ETC provides only a very limited benefit in areas such as air-fuel ratio control, exhaust emissions and fuel consumption reduction, working in concert with other technologies such as gasoline direct injection.

Failure Analysis of Acceleration Pedal Position Sensors

A failing acceleration pedal position sensor can illuminate the Malfunction Indicator Light (MIL), and may cause the vehicle to have drive-ability problems such as poor acceleration or limited vehicle speed. Typically acceleration pedal position sensors fail due to the constant contact of the movable wiper arm over the sensor element. A quick way to check the sensor is to look for smooth voltage changes on the signal wire as the Accelerator Pedal sensor is being depressed and released. (Note: most Accelerator Pedal sensors have multiple sensors in the same housing.)