Skip the auto shop - Our mechanics make house calls

Symptoms of a Bad or Failing Throttle/Accelerator Pedal Position Sensor

pedal position sensor

Bad or Failing Throttle/Accelerator Pedal Position Sensor Inspection

by a top-rated mechanic at your home or office

The days of having to constantly adjust the throttle cable due to a loose nut on the carburetor are long gone. Today's modern cars, trucks, and SUVs are all equipped with an electronic throttle control system that contains an accelerator pedal position (APP) sensor. This sensor's primary job is to monitor the position of the throttle pedal and send an electronic signal to open the throttle body as you depress the gas pedal. Although this device often lasts the entire lifespan of your vehicle, there are occasions when it will fail, wear out or need to be replaced.

The APP sensor essentially tells your engine how fast or slow to drive as you press the gas pedal. When you press down or lift off the throttle, it sends an electrical signal to the vehicle’s ECU or ECM as it's also referred to, and then transmits that signal to the fuel system. The primary reason why this part would fail is due to exposure to high heat as it's typically located on the floorboard and next to the firewall of the vehicle. Unfortunately, this part can't be repaired, so when a certified mechanic diagnoses that there is a problem with this device, you'll have to replace the accelerator pedal position sensor.

Like most components on the vehicle, a bad or failing APP sensor will display a few warning symptoms including triggering error codes, warning lights and a few physical symptoms that should alert the driver that a problem exists. Listed below are a few of these warning signs.

HAVE SYMPTOMS OF CAR TROUBLE?
Get an $80 diagnostic
by a top-rated mechanic at your home or office.

Get a quote · Book an Appointment · Our expert mechanics come to you.

1. Engine throttle is inconsistent

When you press down on the gas pedal, your engine should respond directly and instantly. However, when a problem with the APP sensor exists, the vehicle's ability to consistently accelerate or decelerate as directed by the driver will be reduced. This could cause a serious safety situation as essentially the driver is not in control of the vehicle. When this occurs, you should pull your vehicle to a safe place off the road and contact a mechanic as soon as possible to inspect the reason why throttle control is not consistent.

2. Engine does not run efficiently

When the APP sensor is not functioning properly, it will also have problems with fuel efficiency. Besides monitoring and applying throttle pressure to the throttle body, it also helps to stabilize the throttle control. It's designed to take input from the driver, but steady the application of fuel pressure as it relays the information from the ECU to the throttle body of the vehicle. If the sensor is not able to transmit this information to the ECU correctly due to a loose wire, being worn out or have broken entirely, you'll notice a huge difference in fuel economy.

HAVE SYMPTOMS OF CAR TROUBLE?
Get your car fixed at your home or office.

Get a quote · Book an Appointment · Our expert mechanics come to you.

3. Check Engine Light comes on

Since the APP sensor is monitored by the ECU, it is one of those components that will trigger an error code in the ECU when an issue is discovered. This will signal the Check Engine Light to illuminate on the dashboard. Anytime this light is on, you should take it seriously as there are multiple components that will trigger this warning light. Contact a local ASE certified mechanic if the Check Engine Light comes on so they can properly diagnose the problem and correct it quickly. In order to work properly, all of the sensors inside your car must function at 100 percent efficiency.

When one fails, it can impact the operation of the entire vehicle. Anytime you notice any of the above symptoms or warning signs, you should contact a local ASE certified mechanic through YourMechanic. Our professional and experienced automotive technicians can travel to your home or workplace to complete diagnostic inspections and repairs of virtually any mechanical or electrical problem with your vehicle – including replacing the APP sensor.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Still not sure about your car's issue?
Diagnose your car
What kind of issue are you experiencing?
Brakes are squeaking
Car is not starting
Car is overheating
Car is shaking (vibrating)
Fluids are leaking
Heating and A/C
Smoke or steam is coming out of the car
Warning light is on
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

How to Find the Keyless Code on a Ford Explorer or Mercury Mountaineer
Many Ford Explorers and Mercury Mountaineers were manufactured with an option known as the Ford keyless entry keypad. Some models refer to it as SecuriCode as well. It...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...


Related questions

Q: Front end shudder, CEL and 4LO lights on

Hey there. You need to have the AWD system checked to see why the light is 4LO. This can be an internal problem in the transmission transfer case lock up. This transfer case uses an electronic clutch that can shutter...

Q: Car hesitates when accelerating

Hi there. It is very likely that a faulty throttle position sensor (TPS) is causing your problem. The TPS receives signals from your computer telling it where to position the throttle at any given time. A faulty TPS will also...

Q: Check engine light on, temperature goes to hot, noisy engine, car shuddring and turns off.

Fault codes need to be read out from the engine computer. There is a technical service bulletin (TSB) out by Lexus that points to a faulty thermostat causing a Check Engine Light, and that the thermostat should be replaced based...