Skip the auto shop - Our mechanics make house calls

Symptoms of a Bad or Failing Throttle Position Sensor

throttle position sesnsor

Bad or Failing Throttle Position Sensor Inspection

by a top-rated mechanic at your home or office

The throttle position sensor is part of your vehicle fuel management system that helps ensure your engine is getting the right mixture of fuel and air at every moment. The throttle position sensor provides the most direct signal to the fuel injection system of what power demands are being made of the engine. The TPS signal is measured and combined many times per second with other data such as air temperature, engine RPM, (actual) air mass flow, and how quickly the throttle position may be changing. These data determine precisely how much fuel to inject into the engine for the next few milliseconds. This is done repeatedly, many times per second. If the throttle position sensor and its other sensor partners do their job correctly, your car accelerates, cruises, or coasts down smoothly and efficiently, as you expect.

The throttle position sensor can fail in several ways, all of which result in poor fuel performance at best, and performance limitations that may create safety hazard for you and other motorists at worst. This sensor can fail gradually, or all at once. In most cases, the Check Engine Light is illuminated if a TPS failure is detected. Also, most manufacturers provide a “limp home” mode of operation with reduced power if a failure is detected. This would at least allow getting off a busy highway in a safer manner. Once the TPS begins to fail, even partially, you’ll need to replace it right away. Replacing the TPS will include clearing relevant fault codes, and may require software re-programming of the new TPS module to match other engine management software. This is all best left to a professional mechanic who can provide you with a diagnosis, and then install the correct replacement part.

Here are some common symptoms of a bad or failing throttle position sensor to watch for:

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. Car won’t accelerate or lacks power when accelerating

It may feel as though the car just doesn't accelerate as it should. It may accelerate smoothly, but lack power. On the flip side, it may be that your car suddenly speeds up while you’re driving, even if you haven’t pressed the accelerator. If these symptoms occur, there's a good chance you've got a problem with the throttle position sensor.

2. Engine won’t idle smoothly, idles too slow, or stalls

If you start to experience engine misfires, stalling, rough idling, or poor running at a stop light, these can also be warning signs of a failing throttle position sensor. You don't want to wait to get this checked out!

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. Car accelerates, but won’t exceed a relatively low speed (20-30 mph) or shift up

This is another failure mode of the TPS, which indicates that it is falsely limiting the power being requested with your accelerator pedal foot. This symptom often goes hand in hand with lack-of-power behavior.

4. Check Engine Light comes on, accompanied by any of the above behaviors

The Check Engine Light may come on if you’re having issues with your throttle position sensor. This isn’t always the case though, so don’t wait for this to happen before you get it checked out. If you have any of the above symptoms, have your vehicle checked for trouble codes to make sure that is the problem.

The throttle position sensor is key to getting the desired power and fuel efficiency from your vehicle in any driving situation. As the symptoms listed above make clear, failure of this component has serious safety implications, and must be checked out immediately by a qualified mechanic.

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

P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222 code means The manufacturer specifies a range of acceptable voltage to be produced from the throttle position...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance Related Trouble Codes: P2158: Vehicle Speed Sensor B P2160: Vehicle Speed Sensor B Circuit Low P2161:...


Related questions

Q: Accelerator not as responsive at times.

Hello. This may be a sign of a failing throttle position sensor. The throttle position sensor (TPS) is a sensor used to monitor the throttle position of the throttle plate inside the throttle body in relation to your foot position...

Q: Electronic throttle control not working

This may be a sign of a failing throttle position sensor. This sensor is usually located on the butterfly spindle or shaft so that it can directly monitor the position of the throttle. It relays the position of the throttle...

Q: Problem with replacing the TPS

Your throttle position sensor says it is on the throttle body assembly. Look at the gas pedal position sensor, above the gas pedal, to see if this is the sensor the parts store gave you. This sensor is called the...