Accelerator Pedal Position Sensor Symptoms and Solutions

Accelerator pedal position sensor symptoms are some things you should consider if you suspect that your car is having trouble. The engine control unit or ECU receives signals from the APP sensor, letting your car know how much power to produce.

Accelerator Pedal Position Sensor

An accelerated pedal position sensor failing will cause different problems in your car, including the engine warning light, rough idling, reduced fuel economy, and more. In this guide, we look at the symptoms of a bad APP and how you can fix it.

A List Of Faulty Accelerator Pedal Position Sensor Symptoms 

If there are problems with your accelerator pedal sensor, you will notice some common symptoms that cause issues with your vehicle. Below, we look at the accelerator throttle position sensor symptoms and solutions to it.

1. Check Engine Light Is On

Warning Light of Car

Main Sign  Check Engine Light on the dashboard is on
What To Do Immediately After Park your car and test it or visit a mechanic.
How to Test It Use an OBD-2 scanner to check the code and the meaning.
How to Fix It Clear the trouble codes


If you notice the engine warning light of your car is on, this would be a sign that your accelerator pedal position sensor is faulty. This sensor is an electrical element, and so it sends signals to the Powertrain Control Module. If it is bad, the warning light will come on because it triggers an error code. 

For the PCM to work properly, the electric sensors must also work properly. With the check engine light on your dashboard, it’s important to check your car as soon as possible. The code you will get for a faulty APP is the P2135 diagnostic trouble code. If you don’t get this code, you might have to contact a mechanic to check for the true case of the engine indicator. 

It is easy to use an OBD-2 scanner to check the fault code that your vehicle is giving. Firstly, check under your dashboard for the OBD port and connect it. Then, insert your key in the ignition without starting the engine. Type in your VIN to the scatter, locate the code, and check for the meaning. 

2. Shifting Issues

Throttle Position Sensor

Main Sign  Shifting or Parking Problems
What To Do Immediately After Pull over and contact a mechanic
How to Test It Press the pedal and check how the gear shifts.
How to Fix It
  • Clean the sensor 
  • Repair the damaged wiring harness 
  • Replace the sensor 
  • Contact a mechanic. 


Another clear symptom of a bad accelerator throttle position sensor is shifting problems or gear problems. If your APP is faulty, it will send the wrong signals to the powertrain control module or PCM. This would make it difficult for you to use your gear when shifting or parking. 

With the wrong signals going to the main computer in your vehicle, it will result in poor automatic transmission shifting. You might asl notice that your gear jerks when you press the throttle pedal. Pressing the pedal when you have a bad sensor will cause slow, delayed, or quick varying signals, which leads to shifting issues.

The faulty APP will also give out delayed signals or different signals to the gear. Your car will try to understand this and adjust to it, making it harder for you to shift gears or park. If you notice that your car is not shifting gears as it used to, you can check the accelerator pedal position sensor location or contact a mechanic. 

3. Car Hesitates to Move When Pressing the Gas Pedal

Gas Pedal Problems in Car

Main Sign  The car hesitates; it feels like dragging, and it does not drive as fast as usual.
What To Do Immediately After Pull over and wait for a mechanic to prevent accidents.
How to Test It Check how your car responds to pressing the pedal when driving.
How to Fix It
  • Consider cleaning the pedal sensor 
  • Checking for damaged wires 
  • Getting a position sensor replacement 
  • Contacting a mechanic.


If you notice that your car hesitates when you drive, this could be a sign that the accelerator throttle position sensor works wrong. You will most likely notice if your car is no longer driving as it used to because you will be used to it. Thus, it would be easy to identify if your car is hesitating.

In cases like this, the best thing to do is pull over immediately. If not, you can get into an accident while trying to drag your car along the road. Then, contact a mechanic since a faulty pedal symptom can be dangerous

Your car’s hesitation might be because there is debris on the pedal sensor, making it hard to drive faster than it is supposed to. You can clean your sensor and try driving again. Also, there might be a faulty connection between the APP and the engine control unit. 

4. Acceleration Problems

Fixing Acceleration Problems

Main Sign  The car suddenly stops moving, and uneven acceleration and inconsistent acceleration. 
What To Do Immediately After Stop driving, park in a safe location, and contact a mechanic.  
How to Test It You might notice this when driving; press your pedal and check the response.
How to Fix It It’s advisable to repair or replace the APP. 


When you press the gas pedal of your car, your engine is meant to respond at once and speed up the car. But if your accelerator throttle position sensor is faulty, you will notice that your car will be unable to properly accelerate or decelerate as you depress the pedal. This reduces the control you have over your car and can be a road hazard.

Acceleration problems can be in the form of uneven or inconsistent acceleration. Your car might also suddenly stop moving when you’re driving. Also, your car might not be able to speed up to a certain point if there are accelerator issues. Even when you press the pedal, you might notice your car going at the same speed.

If you notice your car’s ability to accelerate is limited, pull over and contact a mechanic to check the APP and repair the problem. You can also check the APP and repair or replace it, depending on how much damage there is. 

5. Rough Idling

Checking the Fuel Mixture 

Main Sign  It is not idling smoothly
What To Do Immediately After Check the fuel mixture, and if it’s right, repair the APP.
How to Test It Leave your car idle and observe it.
How to Fix It Repair or replace the APP sensor 


Another sign that the accelerator pedal sensor is faulty or damaged is if your car is idling roughly. Rough idling is obvious because your engine will be shaking or might make a rattling noise when idling. It will also consume a lot of fuel. 

The ideal RPM of a car engine is between 600 and 700 rotations per minute, and this is when your car is idling smoothly and consuming little fuel. If you notice rough idling, the go-to culprit is usually the fuel mixture. Check your fuel mixture, and if the problem persists, it could be the APP.

If your pedal sensor is causing a rough idle, it would be best to drive your car to the mechanic or asses the sensor yourself. It might be affected by debris which you can clean up. If your car is still idling roughly, you can consider repairing or replacing the sensor.

6. Lower Engine Power

Maintain Engine Performance 

Main Sign  Reduction in engine performance, poor fuel economy
What To Do Immediately After Pull over and contact a mechanic. 
How to Test It Check for sounds in the engine, and check your fuel economy
How to Fix It Repair damaged wires in the APP, and repair or replace the sensor.


A bad accelerator pedal sensor can reduce your engine performance and also your fuel economy. You might notice a rattling engine, sounds in your engine, or your car using more fuel than usual. The sensor is in charge of monitoring throttle pressure and also applies it to the throttle body and stabilizes electronic throttle control. If it is faulty, it will not be able to do this. 

The sensor also delivers data to the throttle body in your car from the PCM and stabilizes your fuel pressure. If you notice a reduction in engine performance, it would be because the bad throttle position sensor has damaged, corroded or frayed wiring that you need to repair.

The damaged wiring will cause the sensor to send inaccurate readings to the PCM. If you notice these signs, you should contact a professional to check your APP. You might have to replace the entire sensor if it is damaged beyond repair. 

7. Increased or Decreased Fuel Economy 

Bad Accelerator Pedal

Main Sign  Gas lasting longer or less than before reduced engine performance
What To Do Immediately After Assess your APP, and contact a mechanic. 
How to Test It Check how much gas you have used so far.
How to Fix It Repair or replace the sensor


Another bad accelerator pedal sensor symptom is a change in your fuel efficiency. With the faulty sensor, you will deal with an increase or decrease in fuel efficiency. If the APP is damaged, it will send a wrong signal to the engine control module. This causes the engine to either use too much or too little fuel.

The faulty APP sensor will eventually lead to higher or lower fuel economy. Although it sounds like having better fuel consumption is a good thing, it will eventually damage your engine, which will be more expensive to fix than just a gas pedal sensor. It’s best to fix it as soon as possible.

Can Temporary Fixes for a Crankshaft Position Sensor Also Work for an Accelerator Pedal Position Sensor?

If you are considering a temporary fix for a crankshaft position sensor, it is crucial to note that such fixes may not apply to an accelerator pedal position sensor. These sensors serve different purposes and are responsible for different functions in a vehicle’s engine management system. Therefore, a temporary fix for crankshaft position is unlikely to work for an accelerator pedal position sensor.


With our guide on the important accelerator pedal position sensor symptoms, you can identify problems with your car and repair them immediately. Here is a rundown of this article:

  • A faulty accelerator pedal position sensor sends wrong signals to the car’s PCM and can cause different issues.
  • The engine warning light being on is the main symptom of a bad APP.
  • Other symptoms of a faulty APP include shifting, acceleration, and fuel economy issues, reduced engine performance, and your car hesitating.

If you notice a problem with your accelerator pedal position sensor or identify any of the symptoms in this guide, you should contact a professional mechanic. If you have mechanical knowledge, you can repair it yourself. 


5/5 - (17 votes)
Ran When Parked