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Symptoms of a Bad Throttle Position Sensor

8 Key Symptoms of a Bad Throttle Position Sensor

Similar to the motor cortex in the human brain, a throttle position sensor controls a throttle body, one of the most crucial parts of your car that keeps your engine running. Imagine a tiny car module that displays how far you have depressed the gas pedal. It collects this data and compares it to the mass airflow sensor and engine RPM to make sure that the right amount of air or fuel is going into your engine.

In modern vehicles, the throttle position sensor can malfunction occasionally. This could lead to stalling, more fuel system damage, poor fuel economy, and a variety of other problems.

In order to control engine output, the air and fuel mixture must be adjusted, and without a throttle position sensor (TPS), the engine is unable to determine how much fuel or air to deliver.

How can we determine if the TPS has malfunctioned? Here are eight symptoms of a bad throttle position sensor.

8 Common Symptoms of Throttle Position Sensor Failure

Common Symptoms of Throttle Position Sensor Failure
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Below are the eight most common symptoms of a bad throttle position sensor:

  1. Car Won’t Accelerate, No Power

Another sign of a malfunctioning TPS is that no matter how hard you press the accelerator, your car won’t move forward. In rarer cases, the car suddenly gains speed by itself.

This is particularly frightening, especially for novice drivers. The car will typically not accelerate past 30 or 50 kilometers per hour. 

Keep your cool and shift to neutral to deal with this. Try to shut off the engine if you’re unable to do that.  Use your hazard lights if this happens in the middle of a busy road. Also, taking the keys out of the ignition could stop the steering wheel from turning.

It is important to keep in mind that incorrect input from a driver can also cause this symptom.

  1. Bad fuel economy

In the event that the TPS is faulty, the engine may consume an abnormally high amount of both air and fuel. This will have a significant impact on your car’s fuel economy.

  1. Engine Won’t Idle Smoothly, or Stalls

Driving with an uneven idle or hearing your engine misfire can be a sign that the TPS is failing. Engines that are starved of air or fuel as a result of a poor TPS typically stall as well. 

  1. Gear Shifting Difficulties

When it comes to modern cars with automatic transmissions, the transmission will take into account a number of different factors before deciding when and what gear to shift into. The information that was gleaned from the TPS is included among these variables. Your automatic transmission might have problems if the mentioned component malfunctions.

  1. Car Goes Into Limp Mode

In some models of cars, the car can tell when one of its most important parts isn’t working right. This includes the TPS.

The vehicle will enter “limp mode” in order to prevent any further damage from occurring. It is slower than what a car is normally capable of doing, but it is just enough for the owner to take it back home or to a mechanic.

  1. Starting Problems

When starting a car with an internal combustion engine, typically more fuel and air are required than when the engine is idling or even when it is at cruising speed. Because of this, one of the possible symptoms of a faulty throttle position sensor is that you might have trouble starting your car because the engine isn’t getting the appropriate amount of fuel. If the situation is particularly dire, your car might not start at all.

  1. Weird Buckling and Jerking of the Car

One of the most common signs of a faulty throttle position sensor is a feeling that the whole car is shaking or buckling. There are a number of factors that could be at play here, but one of them is that the ECU is receiving consistently inaccurate readings from the TPS. Inconsistent power is a direct consequence of this issue.

  1. The Check Engine Light Illuminates

The engine warning light coming on is one of the most obvious signs that a car’s TPS is faulty. Be aware that a number of other problems can cause the check engine light to come on, and there’s even a chance that it’s a false reading.

Borrow an OBD-II reader and run a system check to make sure.

TPS Solution

The solution is simple after the issue has been identified; all that needs to be done is to change the throttle position sensor. You are in luck, since this is a task that you can do on your own.

Once you’ve found the TPS, you’ll need to disconnect the negative battery terminal before you can remove the sensor’s electrical connection. After that, remove the sensor mounting screws with a screwdriver, and then pull up on the sensor itself. After replacing the old sensor with a new one and doing the previous procedures in reverse order, the throttle position sensor problem should be fixed.

Is it a costly endeavor to repair a throttle position sensor?

Even though it is not a complete motor replacement, installing a throttle sensor can still be challenging. This job’s cost might end up being quite high for you, depending on the kind of vehicle you have. If the throttle is located in an area that is both open and easily accessible on your vehicle, then the repair work shouldn’t be too difficult, and the total cost of the parts and labor combined could be less than $500.

Now, things can get tricky with some cars because the throttle pedal is hard to reach at first. To get to it, you have to take apart a lot of parts, like the intake manifold and the air filter box. It is entirely possible that the price will increase by a factor of two to go up to one thousand dollars just for one sensor.

Is it worth repairing the throttle position sensor?

There are some problems that should be fixed, while others should not. In the event that your car has a faulty TPS but is still relatively new and has a low number of miles on the odometer, then it still has a long road ahead of it, and repairing it might be worthwhile. Now, if your vehicle already has damage, has a high mileage, and now has mechanical issues, there is no need to go for repairs.


If there is a problem with your TPS, the Check Engine Light may illuminate on your dashboard.  However, since this is not always the case, you shouldn’t wait for the check engine light to come on before having any of the symptoms listed above evaluated by a professional. In order to identify the cause of the issue with your vehicle, you should have the trouble codes checked.

No matter how you drive, the throttle position sensor is the most important part if you want your car to have the power and fuel efficiency you want. Failure of this component has serious implications for the safety of the vehicle and should be checked out right away by a qualified mechanic. The symptoms that have been listed above might be of great help to you.

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