Throttle Position Sensor – TPS Sensor

This sensor is also known as Throttle Position Sensor or Throttle Gate Position. It is responsible for verifying the position of the butterfly that is right at the inlet of your vehicle’s engine. So, learn all about this sensor that is activated when you step on the pedal of your vehicle to accelerate.

What is the TPS Sensor?

Throttle Position Sensor

The TPS Sensor is a small transmitter that controls fuel injection through a signal that is sent to the computer. As the throttle opens, the air is allowed to enter the engine. This action is possible thanks to a guide operated by the accelerator or pedal.

In other words, the TPS is a power sensor, powered by 5 volts. To work, it uses a resistor and a movable brush. The voltage varies depending on the shaft position and resistance.

What is it for? TPS Sensor Function

The Throttle Position Sensor is responsible for letting the electronic central unit or ECU know what state the throttle is in. If this is not activated, you will not be able to respond to the driver’s orders.

Depending on the acceleration of the vehicle the throttle position sensor can move up to 100 degrees. Obviously, if the vehicle is not running, the throttle is closed and the sensor is at zero degrees.

The tips Sensor influences the following functions:

  • Doses the amount of fuel.
  • It controls the march in minimum.
  • Turn off the air conditioning when there is sudden acceleration.
  • Control the operation of the Canister.

How does the TPS Sensor work?

The acceleration sensor indicates the position and opening of the throttle. This information is sent to the switchboard or main computer. Here, the information is validated to make the engine work properly.

Throttle Position Sensor Location

To find out what the TPS Sensor is, look at the throttle body of the vehicle. It is located on the throttle frame and connects to the throttle shaft. In the definition, we have explained that through the throttle body the airflow enters the engine in appropriate amounts. In general, if you have an automatic vehicle such as Toyota, the TPS also responds to the control of the gears.

TPS Sensor Types

There are basically two types of Throttle Position Sensors with little difference from each other. One of them has 3 terminals that include a 5-volt current, a ground, and a third signal to the computer. The second TPS Sensor has an additional term that is for the idle function.

OBD2 codes related to the TPS Sensor

The TPS Sensor can present faults that are diagnosed with the OBD2 protocol, using a scanner. In this case, the most common codes are:

  • P0122: It means that the sensor circuit A output voltage is below the limit.
  • P0123: This code is the opposite of the previous one. That is, the ECM or engine control module exceeds the voltage expected by the sensor.

Common Throttle Position Sensor Faults

When the TPS Sensor is not working properly, the computer does not send the correct signals to the engine for combustion. In these cases, there are some fault symptoms such as:

  • Unstable idle speed or over-accelerated engine.
  • Lack of power which may indicate a damaged TPS Sensor.
  • Motor jerks, which are common when one of the sensor pins is broken.
  • Check engine light on on engine dash.
  • Mismatch with temperature that can change abruptly.

Any of these faults may suggest a damaged, broken, or misplaced TPS Sensor.

How to test if the TPS Sensor works?

To check if the Throttle Position Sensor is in good working order, a multimeter or oscilloscope is required for the check. The ideal is to check the TPS Sensor every 20 thousand kilometers. In addition, the points to check are the cables that are not broken and that the harness is free of rust.

Now measure at the TPS Sensor connector according to the following steps:

  1. Measure the current from the potentiometer to see if it sends the signal back.
  2. With an oscilloscope on the TPS Sensor, move the throttle and verify that the signal goes up or down. If it does, it means that the sensor is working properly.
  3. Sensor signals should equal 5 volts at any point.

How to clean the TPS Sensor?

It must be said, that the Throttle Position Sensor does not clean itself. What you need to clean is the throttle body to ensure optimal operation of the TPS Sensor. For this, you need a clean cloth and carburetor fluid. Now, remove all the excess dust and dirt around it.

In other cases, the throttle body may be very dirty. So it is best to disassemble it and apply a special solvent to clean it. It is important to remove the TPS Sensor during cleaning. In this way, you avoid contaminating the cables or damaging the sensor.

In short, you already know how the TPS Sensor works in the engine of your vehicle. Basically, it is responsible for sending signals so that the engine runs at a correct revolution. Also, you will be able to identify the most common faults and solutions that this piece presents.

Throttle Position Sensor – TPS Sensor

Hi, this is Viney Bhatia, a blogger, an engineer, and your virtual mechanic. You'll get all the latest information about cars, reviews, tips, service methods, and various other things related to automobiles on our blog.

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