Your One-Stop Guide to Throttle Position Sensors

Whenever you press your foot on the accelerator while driving, your fuel management system releases gas into the engine, where the gas burns, allowing your car to propel itself forward. However, to do so successfully, several components within the fuel management system work together to measure and distribute the right amount of gas—and one of those parts is the throttle position sensor (TPS).

So what is a throttle position sensor, and what role does it play in helping your car run smoothly? We have the complete guide to this component below.

What Is a Throttle Position Sensor?

For car engines to operate correctly, one of the many things they need is the right ratio of gas to air delivered continuously while the vehicle is in operation. Without the right balance of the two, the engine won't run as effectively as it could, meaning you can lose fuel efficiency if all the components of the fuel management system don't work together.

The role of the throttle position sensor is as the name suggests: it senses and measures various factors that impact the efficiency of the engine, such as the:

●  Air temperature

●  Air mass flow

●  Changes in throttle position

●  Engine RPM

A fully functioning throttle position sensor will measure these factors several times per second to get an accurate read on the demands of the vehicle and engine. Using that information, it then signals to the fuel injection system how much gas and air use while monitoring the valve's position, helping the vehicle run at the most effective levels of fuel consumption and maintain other areas of operation.

Aside from miles per gallon ratings, the throttle position can also impact how your vehicle operates while cruising, coasting, and accelerating—which means that if the TPS starts to fail, you can expect more than a higher cost at the pump.

What Can Happen if Your TPS Goes Bad?

We've already mentioned fuel efficiency and how the throttle position sensor can help in this area, but if the TPS malfunctions and misreads how much gas your engine needs, you may burn through more than you need, making you empty your tank faster than you would otherwise.

Additionally, the TPS misreading signals from the other parts of your engine can mean that you won't get an accurate response from your vehicle when you press down on the accelerator, potentially going faster or slower than you intended. If this issue happens in heavy traffic, it can become a safety hazard for both you and other vehicles.

Other issues that can come from a malfunctioning throttle position sensor can include problems if you need to set base ignition timing or make troubles when you try to change gears.

The problems that you encounter will depend on which areas of the TPS are no longer working, as it's possible for some areas to stop functioning while others remain on or for the whole system to fail at once. For safety purposes, many manufacturers have a mode where the TPS will stay working at lower power levels to give drivers time to stop and get repairs before a more significant issue or damage occurs.

What Signs Indicate a Failing Throttle Position Sensor?

Since a malfunctioning throttle position sensor can cause serious issues, it's best to replace the part with a new one as soon as possible. Recognizing the signs can make the difference between nipping the problem in the bud or needing to visit a mechanic because your car has sustained more extensive damage.

Here are some signs that may indicate that your throttle position sensor is malfunctioning or failing.

Issues with Acceleration

When the TPS provides incorrect readings to the fuel management system, you can run into problems with your car accelerating, such as:

●   The vehicle not accelerating enough when you press on the gas pedal

●   When you accelerate, the car jerks

●   The car may accelerate on its own, even when you don't touch the gas pedal

●  The vehicle accelerates but caps out at a relatively low speed, such as thirty miles per hour

Issues with Idling or Stalling

Depending on what area of the TPS is malfunctioning, your vehicle may idle roughly when you've stopped, rather than smoothly. This issue can occur because the throttle position sensor isn't reading the fully shut valve correctly, or it can send inaccurate input. This latter problem can also cause your engine to misfire or stall out at any time.

Sudden Changes in Fuel Consumption

While plenty of smaller factors like how we drive can impact a vehicles' MPG rate, sudden changes in how much gas cars, SUVs, and small trucks use can indicate that the sensor has malfunctioned, especially if you need to refuel more often.

You Have a Check Engine or Warning Light Lit

Sometimes your check engine light may turn on when your vehicle detects an issue with the throttle position sensor. While this warning indicator can mean other things, if you notice one of the other signs on this list and the light turns on, the issue will likely involve the throttle position sensor.

If you suspect the TPS may be the issue, you want to have it repaired as soon as possible before the system fails and causes problems while driving.

Can My Car Start Without a Functioning Throttle Position Sensor?

Engines require the right mix of air and fuel not only to run but also to start up. Depending on what malfunction is going on with your throttle position sensor, it could potentially prevent your vehicle from starting up in the first place, let alone driving correctly. If the issue has gotten bad enough that the fuel management system can't give the right ratios to turn over the engine, you likely don't want to drive in it, either.

Even if a vehicle starts while the TPS is having issues, more severe problems can make the car stall out at any time, which also poses a risk. While some manufacturers have included a low power mode on their throttle position sensors to keep them operating, the best option is to stay cautious and take the vehicle to a mechanic as soon as possible—especially if you own an older car that may not have this protection.

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You don't want to skip on getting a new TPS when needed; otherwise, you may end up in an accident and have to worry about fitting a total car value into your budget, instead of a single repair cost. Wrecks can result in medical bills, repair costs, and increased auto insurance premiums.

Can I Replace a Throttle Position Sensor on My Own?

For many people, they would rather handle automotive repairs on their own instead of relying on a mechanic, and it is technically possible to perform a DIY throttle position sensor replacement if you want to, but this job is one where it's better to have a professional handle the process.

While the swapping of parts isn't as complicated as some other procedures, the issue for inexperienced DIYers with this procedure is in the programming of the TPS. Remember that these sensors do their job by processing information about the fuel management system and determining the correct amount of gas to use—and how it calculates that info is essential to a smoothly operating vehicle.

Incorrect programming when replacing a throttle position sensor can cause similar issues to have a malfunctioning one, especially if the TPS settings much up with a vehicle vastly different from your own. While you can reduce the risk of this issue by being careful when researching settings, a professional mechanic will ensure everything is suitable for the make and model of your vehicle.

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