6 Symptoms of a bad Accelerator Pedal Position Sensor & Replacement Cost

Accelerator Pedal Sensor

Modern vehicles are equipped with many sensors and computers to automatically and precisely manage basic car controls.

They help to achieve better gas mileage and a smoother, comfortable, and safe drive.

Almost every modern car now has a sensor called the TPS and an accelerator pedal position sensor. As the name implies, these sensors are precision devices that determine the position of the accelerator pedal.

In this article, you will find the most common symptoms of a bad accelerator pedal position sensor.

6 Symptoms of a Bad Accelerator Pedal Position Sensor

  1. Your Car hesitates to move when the gas pedal is pressed
  2. The engine doesn’t idle smoothly
  3. Your car doesn’t accelerate over a specific limit
  4. Your car won’t shift up or jerks upon depressing the pedal
  5. Bad Fuel Consumption
  6. Check engine light

A failing accelerator pedal sensor’s impact is pretty much obvious as it directly affects how the car drives and responds to the pedal and gas mileage.

If any of these symptoms occur or your car isn’t responding accurately when you press the gas pedal, you should pull over immediately and call a mechanic.

Here is a more detailed list of the most common symptoms of a bad accelerator pedal position sensor.

Your car hesitates to move when the gas pedal is pressed

Slow Acceleration

This symptom is easy to detect as every owner eventually gets familiar with how their car responds to pressing the gas pedal. If you feel that your car is hesitating to move, your accelerator pedal sensor could be failing.

In such a case, it is advised to pull over immediately and call a mechanic since bad pedal timing can prove to be fatal.

Rough Idle

Car Engine Rough Idle E1609793094987

The optimal RPM of a car engine is around 600 to 700 rotations per minute. At these RPMs, the engine idles smoothly without shaking and consumes little fuel. If your car is unable to idle smoothly, a bad accelerator pedal sensor could be the reason besides the fuel mixture.

Your car doesn’t accelerate over a specific limit

Slow Acceleration Car

If your car is only able to accelerate up to a point and won’t go faster beyond that speed, your accelerator pedal sensor is not able to send positioning signals accurately, which causes your car not to speed up beyond a point of pressing the gas pedal.

Your car won’t shift up or jerks upon depressing the pedal

Automatic Shifting

If the accelerator pedal sensor isn’t working as it should, it will give out incorrect reading to the car’s automatic transmission computer. In such cases, because the sensor is bad.

Depressing it would sometimes give out delayed signals or a burst of varying signals, which your car’s computer tries to accumulate and use to adjust the mixture.

You experience low gas mileage

Refuel Car

Your car’s throttle position sensor is often at its failing stage, but the effects aren’t obvious to you. You may not be noticing a delayed response from the pedal, but if you see low gas mileage, it could mean that the car’s throttle position sensor is working but not as accurate as it should be.

Check Engine Light

Check Engine Light On Dashboard E1609869927250

Modern cars have a monitoring system over all the sensors in the car engine. If the engine control unit suspects that one of these sensors is broken and sending out a wrong signal – it will light up the check engine light.

If your check engine light is on, you should definitely check the trouble codes with an automotive scan tool.

What is an Accelerator Pedal Position Sensor?

Accelerator Pedal

Modern cars do not have a wire between the accelerator and throttle body; instead, they use an electronic system.

A driver continually depresses the accelerator pedal giving it a varying amount of pressure, which determines how the car moves forward.

The TPS sensor and the accelerator pedal sensor tracks the gas pedal’s movement, which sends signals to the car’s computer. The computer then uses that information to adjust the air-fuel mixture and the throttle body valve according to the gas pedal position, current speed, the air temperature, MAF reading, and RPM. The result is a smooth and responsive drive.

Some cars use both an accelerator pedal position sensor on the pedal and one TPS sensor on the throttle body, while some cars only have a TPS sensor on the throttle body. 

A TPS sensor’s importance can be emphasized as it can affect the gas mileage and engine response.

Accelerator Pedal Position Sensor Location

Accelerator Pedal Position Sensor Location

The accelerator pedal position sensor is located inside of the accelerator pedal. In some cases, it is possible to replace just the sensor – but on other car models, you have to replace the whole accelerator pedal.

Removing the accelerator pedal can sometimes be challenging, but it is pretty straightforward on most car models.

Accelerator Pedal Position Sensor Replacement Cost

The average accelerator pedal sensor replacement cost is between $100 and $300, depending on the car model and labor costs. The accelerator pedal sensor usually costs between $50 and $200. The labor cost can range from $50 to $100 at a workshop.

The cost differs a lot depending on if you can replace just the position sensor or, like in some car models – you have to replace the whole accelerator pedal, which makes it much more expensive.

Remember that you sometimes have to calibrate the new accelerator pedal position sensor, which can only be done with a diagnostic tool.

Written by: Magnus Sellén

Founder, owner & main author of Mechanic Base. I have been repairing cars for more than 10 years, specialized in advanced diagnostics & troubleshooting. I have also been a drifting driver and mechanic for over 7 years.