A growing number of electronic components are being installed in modern vehicles. This is due, in part, to mandates from on high, such as those requiring less fuel and fewer pollutants. Electronic components are increasingly being utilized to enhance both active and passive safety, making driving more comfortable. An essential element of a modern car is the Accelerator Pedal Position sensor. The movement of the accelerator pedal is transformed into electrical impulses, which play a sensing role in the APP’s engine control.

Overview of the Pedal Position Sensor

There are no mechanical links between the accelerator button and the throttle body in the same car. Instead, there are electronic systems. Electronic technologies are used to figure out where the accelerator button is instead of mechanical parts. The most likely place for the APP sensor to be is where the accelerator button is. 

There are many types of sensors, such as phase shifters and Hall effect sensors. No matter what kind of sensor it is, its job is the same: it lets the ECM (engine control module) know exactly how the driver moves the pedals. These sensors send information to the ECM that helps it figure out the right amount of fuel and air to feed the engine. This makes sure that the acceleration process goes smoothly and efficiently.

Workings Of The Accelerator Pedal Position Sensor

The static motion of the accelerator pedal position sensor is one of the main features.

An ECU (engine control unit) receives an APP signal (acceleration pedal position sensor) connected to the acceleration pedal. Most acceleration-sensing devices for pedals are set up with two potentiometers to provide added reliability. 

Each potentiometer is supplied with power from the ECU to increase the cables to 6. The potentiometer with a carbon track contacting the power supply on one side and the ground on the other is the component use for this purpose. A carbon track picks a sensor voltage, which is mechanically attached to the accelerator pedal.

The sensor should be equipped with two potentiometers, one of which has a regular power supply connected to it. As a result, both signals are equal except for a different offset.

Faulty Accelerator Pedal Position Sensor Symptoms

There are various symptoms when your car’s engine is not working properly. Here are some significant symptoms that will let you solve the problem of a faulty APP.

Rough Idling:

Inconsistent idling, which affects fuel supply and engine stability, might be caused by a defective APP sensor.

Limited Acceleration:

If the car struggles to reach more incredible speeds, it’s a symptom that the APP sensor isn’t giving the engine the signals it needs to work correctly.

Inefficient Engine:

If the APP sensor isn’t working properly, it will not keep the throttle control and fuel pressure steady, reducing fuel economy.

Inconsistent Acceleration:

A slow response from the accelerator pedal can risk the driver’s control and safety if the APP sensor malfunctions.

Problems with Transmission:

If the APP sensor isn’t working properly, the automatic gearbox shifting can be affected. It leads to shaky movements and signal delays of the gearbox control module.

Malfunction Indicator Light (MIL):

Typically, a P2135 Diagnostic Trouble Code (DTC) shows when the APP sensor fails, and the Malfunction Indicator Lamp (MIL) goes off. Only a qualified mechanic should be able to identify and fix the problem.

How To Reset Accelerator Pedal Position Sensor

There are a few universal methods for resetting the accelerator pedal position sensor. However, the specifics could change based on your vehicle’s model and manufacturer. For more help, check your car’s owner’s manual or talk to a professional mechanic. But here’s a general guide that works for a lot of cars:

Switch Off the Engine:

First, ensure the engine is off and remove the keys from the ignition.

Take the battery unit out:

Resetting the vehicle’s electrical system is as simple as disconnecting the negative battery wire. Fixing any mistakes stored in the car’s computer, particularly those associated with the accelerator pedal position sensor, can achieve. For around 5 to 10 minutes, keep the battery unplugged.

Reconnect the Battery:

Once the time has passed, attach the negative battery line back to the battery. Doing so may assist in resetting the sensor’s settings and the vehicle’s electronic systems.

Switch the Ignition to the “On” Position: 

Switch the ignition key to the “On” position to activate the electronics but not start the engine. You’ll see the number “II” on many ignition keys, indicating this position.

Use the Pedal Release Technique:

Gently depress the accelerator pedal while turning the key to the on position.

Wait a few seconds with the pedal down. Return the pedal to its resting position by slowly releasing it.

Wait and Start the Engine:

After you’ve released the pedal, please turn off the key, wait a few seconds, and then turn it back on. By going through this procedure, the computer in the car may reset itself and identify where the accelerator is located.

Test Drive:

Test the vehicle to check if the accelerator pedal is working correctly. Keep an eye on how the pedal responds and any dashboard warning lights.

Important Notes

Check the Manual:

It is vital to consult your car’s manual for the exact process, as it may differ from vehicle to vehicle.

Error Codes:

If your car’s check engine light is on, the problem could be the accelerator pedal position sensor. To fix it, you may need a diagnostic tool to erase the error codes after resetting your car.

Assistance from Experts:

If you’re unsure how to reset it or if the problem remains after trying that, it’s best to talk to a professional mechanic. Using their training and equipment, they can determine what the problem is.


What is Accelerator Pedal Position Sensor Location?

The mechanism of the accelerator pedal connects to it, so the pedal’s position directly relates to the results from the sensor.

How Do I Calibrate My Accelerator Pedal Position Sensor?

It’s essential to ensure the ignition switch is ON and slowly and thoroughly lower the accelerator pedal from idle to full throttle. This will reset the ECM and the pedal. Do what you need to do three times. The process is finished.

What is the App Sensor Replacement Cost?

A professional repair should be the one to take out and put back in the APP sensor.

It can cost anywhere from $100 to $300 to replace an APP sensor, which includes the tools and the work. The price may change, though, based on the make and model of the car, where the sensor is located, and how much the labor costs.


The Accelerator Pedal Position sensor is a small, straightforward part, but its job is essential to how well a car runs. If you don’t fix problems with the monitor, it could affect your speed and cause safety problems on the road. If there are signs that the APP sensor broke, you should have a professional repair look at the car and fix it. Keeping the APP sensor in good shape will keep the engine running smoothly and make driving safer and more enjoyable.


Nancy is a dedicated writer with years of experience. She is focused on the latest vehicle technology and high-end cars of various brands. She combines her passion for automotive advancements with a clear, engaging writing style, making complex topics accessible and enjoyable for her readers.

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