What Happens When You Unplug Throttle Position Sensor?

The throttle position sensor (TPS) is an important component of a vehicle’s fuel injection system that measures the position of the throttle valve and sends a signal to the engine control module (ECM) to adjust the air-fuel mixture accordingly.

When you unplug your TPS, the ECM will not receive any signal from it and will not be able to adjust the air-fuel mixture correctly. Driving on a highway and your check engine light suddenly comes on could be an indication that your throttle position sensor has been disconnected. 

Aside from that, we will be revealing several other things that might occur when you unplug your throttle in this post. But before then, let’s understand what the throttle position sensor means and the role it plays in your car. 

Throttle Position Sensor

What is a Throttle Position Sensor?

The throttle position sensor also referred to as a TPS, is an electrical device used to track the location of the vehicle’s throttle valve. It is a crucial component of the vehicle’s engine control system, and it is either inside or on the throttle body assembly. 

The throttle position sensor allows the engine control unit (ECU) of the vehicle to determine precisely the angle and rotational speed of the vehicle throttle valve. 

The ECU determines the throttle position necessary for fuel and air delivery, ignition timing, and other crucial operations using the output data from the throttle position sensor.  

What Happens When Throttle Position Sensor is Unplugged?

1. Check Engine Light Gets Illuminated

When you unplug the throttle position sensor, the dashboard’s check engine light turns on as a first response. A check engine light is a way for your car to communicate with you as the driver and alert you to internal issues.

The check engine light can occasionally come on as a result of minor issues, but it can also signify serious problems that require urgent attention.

But the more time that passes after a check engine light comes on, the more difficult the situation becomes and the more expensive the repairs become. Therefore, it’s wise to investigate and work out the root of the problem. 

2. Poor Acceleration

Your engine’s air and fuel supply can fluctuate if you disconnect the throttle position sensor. Your car’s engine will not function properly and there will be numerous unburned gases and inefficient fuel combustion in the engine. As a result, when you press the gas, your car may not accelerate smoothly.

3. Stalling and Idling

When you disconnect the throttle position sensor, your car won’t idle correctly. The ECM won’t be able to keep a constant idle speed because your engine is not getting the proper amount of fuel and air mixture it requires. When you come to a halt, this may result in the engine stalling out or causing it to idle roughly.

4. Poor Fuel Economy

Your car may use more gasoline than necessary if the TPS is disconnected. This is due to the possibility that the ECM may be unable to regulate the air and fuel mixture successfully. 

This could lead to a rich fuel mixture. When this occurs, your car’s fuel efficiency may suffer, and you might find yourself filling up the tank more frequently than normal.

How to Reconnect Throttle Position Sensor

  • Disconnect the negative battery terminal. By doing this, you’ll avoid any electrical mishaps while you’re repairing the monitor.
  • Located the throttle, unplug the connection and take the sensor out. 
  • Remove any dirt or detritus that may be in the connector or on the sensor.
  • Reconnect the connection and reattach the sensor to the throttle body after cleaning the throttle position sensor.


Do I Need to Reset My ECM if I Reconnect my TPS?

You don’t need to reset the computer if you only reconnected your throttle position sensor. However, you might probably need to reset the ECM if you’re installing a new throttle position sensor.

How Much Time Does a TPS Sensor Need to Reset?

Resetting your throttle position sensors doesn’t take very long. Since you don’t need any equipment other than your car to perform the reprogram, you can do it whenever you want and wherever you are, which means you should be able to do it quickly and effectively.

Does a Throttle Position Sensor Need to be Calibrated?

Yes, it does. If your vehicle has a throttle cable, you have to calibrate the throttle sensor manually. However, if your vehicle has an electronic throttle, turning on the ignition can automatically calibrate the sensor.

How Often Should I Change My Throttle Position Sensor?

It is only necessary to replace your accelerator position sensor if it fails a test. It is best to take your car to a mechanic to be looked at, though, if you observe any problems with how it is performing.

What Happens if my Throttle Position Sensor Malfunctions While Driving? 

Your engine will run poorly if your TPS isn’t functioning properly. In most cases, the engine will idle fine but will have trouble accelerating. This happens because, even though airflow is increasing, the computer isn’t instructing the engine to inject as much fuel as is necessary.

Read: Transmission Fault in Ford Focus


The TPS is a critical component that provides information to the engine control module (ECM). Therefore, unplugging the TPS can cause the ECM to receive inaccurate data. This can cause several issues, such as rough idling and slow acceleration. In addition, it can also activate the check engine light. 

If you suspect that your TPS is faulty, it’s important to have it diagnosed and repaired by a qualified mechanic. This will help ensure that your vehicle runs smoothly and efficiently and that you avoid any potential safety hazards on the road.