The Throttle Position Sensor (TPS) is an integral part of the vehicle’s fuel management system as it determines the correct amount of air-fuel mixture to ensure optimum performance.
The throttle position sensor transmits throttle position data to the engine control module (ECM), and this information helps determine how much fuel should be injected into the engine at the right time.
The throttle position sensor can fail for a number of reasons and, as a result, affect the performance and the fuel consumption of the car, it can drop significantly. In this article we will discuss some of the most common symptoms that occur when the throttle position sensor is damaged or faulty.
Signs of a Bad TPS
1. Poor Acceleration
One of the most common signs of a defective throttle position sensor is delayed or poor acceleration. Delayed acceleration means that there is a considerable time difference between stepping on the accelerator and the actual acceleration of the vehicle.
If you also notice that the car judders when accelerating, this is most likely due to a damaged throttle position sensor.
2. Idle Surging
The term idling refers to the operation of the engine when the vehicle is not actually moving. If you notice that your engine fluctuates when idling, this may be due to an irregular air-fuel mixture, which is related to a faulty throttle position sensor. If the ECM does not receive correct information from the throttle position sensor, the throttle will not function correctly, resulting in idle surging.
3. Check Engine Light
There are several sensors in a vehicle, and if one sensor is not working, the check engine light comes on. Although the check engine light will illuminate for various other reasons, it is advisable to check the throttle sensor, especially if your car has poor acceleration and idle surging.
4. Sudden Surge while Driving at a High Speed
One of the most dangerous effects of a defective throttle position sensor is a sudden increase in speed while driving at high speed on a highway. What happens is that the throttle in the throttle valve may close automatically, and if the driver presses the accelerator pedal too hard, the valve suddenly opens and gives the car a small speed boost.
This happens if the throttle position sensor is damaged and sends an incorrect signal to the throttle valve, causing it to open and close suddenly.
5. Problem with Switching Gears
A poor throttle position sensor causes a problem with acceleration, which in turn causes a problem with the transmission. If you find acceleration problems related to a transmission problem, it is time to check the throttle position sensor.
Cleaning the Throttle Position Sensor
The throttle position sensor works actively while driving, so there is a high probability that it will wear out over time. It is advisable to have the sensor cleaned and serviced before going to a car specialist to have the component replaced, as a dirty sensor will also cause the incorrect information to be transmitted to the ECM.
Cleaning the throttle position sensor is a fairly easy task and requires the following tools:
• Socket Wrench
• Cleaning Solvent
• Additional clean cloth
Step 1: Turn on the Ignition
Turn on the ignition and let the engine run for a few minutes. This will automatically remove some of the dust or particles due to the engine heat.
Step 2: Locate the Throttle Position Sensor
Open the hood of the vehicle and attach the hood stand to ensure that it does not fall down. Remove the engine cover and locate the throttle position sensor. It is located directly inside the throttle body, but if you cannot find it, refer to your vehicle’s manual.
Step Three: Disconnect the Connecting Wires
Once the throttle position sensor is found, you will notice that it is connected by cable. Disconnect all wires to ensure that no current flows through the sensor during the cleaning process. Once the wires are disconnected, remove all nuts and screws and remove the sensor from its place.
Step 4: Clean the Sensor with Solvent
Thoroughly clean the throttle position sensor with the cloth and cleaning solution. Make sure that all dust particles are removed by cleaning the sensor properly. We recommend that you do not use excessive liquid cleaning product to clean the actual sensor as this may cause damage. You can use an electric cleaner such as Amazon’s WD40: WD-40 Specialist Electrical Contact Cleaner with SMART STRAW SPRAYS 2 WAYS 11 OZ
Step 5: Clean with a Dry Towel
When you have cleaned the sensor with the solvent, use a clean, dry towel and gently wipe the sensor to ensure that no liquid is present.
Step 6: Install the Sensor Back
As soon as the cleaning process is completed, reinstall the sensor in its place. Use the socket wrench to tighten all bolts and nuts and close the hood. If you still experience the above symptoms after cleaning the sensor, it is time to replace the sensor.
Throttle Position Sensor Replacement Cost
If you still notice a power interruption, it is time to see a car specialist and have the sensor checked manually. Your mechanic will check the TPS output voltage with the ignition on, with the throttle closed and open. At idle, the output voltage should be 1 volt and will increase as the throttle opens.
When the throttle is wide open, the TPS output should show about 4.5 volts. If the displayed voltage is not within this limit, your TPS is defective and must be replaced.
The average cost of replacing the throttle position sensor is about $100 to $200, the sensor itself costs between $75 and $110, and the labor cost is about $30 to $90. The price varies depending on the vehicle and auto repair shop.