Throttle position sensors are an important part of modern vehicles’ engine management systems. This is used for measuring the position of the throttle valve and provides details to the ECU, or the engine control unit, that uses these values for measuring the accurate fuel injection and ignition time of the engine. Here we will cover details, features, and related factors for the throttle position sensor. Let’s get started with an introduction to the throttle position sensor.
What is a throttle position sensor?
- The throttle position sensor is a sensor type that is used for monitoring the throttle body valve position as a component of the engine ECU system.
- The butterfly spindle connects to this sensor, which aids in accurate throttle position monitoring.
- It also comes in some of the latest versions of sensors, like the closed throttle position sensor, which is used for showing that the throttle is closed.
- Some engine control units also control throttle position with the use of electronic throttle control.
- The TPS is an accelerator pedal sensor that comes with a wide-open throttle, or WOT, sensor.
- The accelerator pedal sensor is part of the electronic throttle control system and is commonly used for the kickdown function of the automatic transmission.
- Currently used sensors are non-contact type; the common non-contact TPS are Hall effect sensors, magnetoresistive sensors, and inductive sensors.
- Potentiometric sensors, multi-finger metallic brushes have contact with the resistive strip, and the butterfly valve is controlled with the use of a mechanical stop to WOT. Resistance chances, and those chances provide input to the ECU.
- The working of the non-contact type TPS based on Hall effect or inductive sensors and magnetic or inductive loops is a dynamic component that is configured on the butterfly valve throttle spindle, and the sensor board is configured in the ETC gearbox that is static.
- If a magnet or inductive loop is configured on a spindle that is rotating from a low mechanical stop to WOT, the magnetic field of the sensors varies. The sensor and voltage are provided to the input at the ECU.
- The two-pole rare earth magnet is employed for TPS since high temperatures are needed for under-hood vehicles.
Throttle Position Sensors Working
- Throttle position sensors operated by measuring the angle of the throttle plate or lever and transmitting data to the ECU. There are two main types of TPS potentiometers: Hall effect-based.
Potentiometer-based TPS:
- This type of TPS comes with a variable resistor that is configured with the throttle shaft. When the throttle opened, the resistance of the potentiometer varied, which gave a voltage signal to the ECU. The ECU uses that signal for finding the position of the throttle and setting fuel injection.
Hall effect-based TPS:
- This TPS uses a magnetic field for the detention of the position of the throttle. The small magnet is configured on the throttle shaft, and when the shaft rotates, it moves over the Hall effect sensor that produces a voltage signal. The ECU employs that signal for finding the position of the throttle and setting fuel injection according to that.
Issues with Throttle Position Sensors
Erratic idle:
- If TPS is not working well, it can be the reason that the engine is faulty or can stall.
Jerk during acceleration:
- The faulty TPS can result in a jerk at the time of acceleration.
Bad fuel economy:
- Improper signals from TPS cause poor fuel economy if there is not an accurate injection.
Check Engine Light:
- The faulty TPS also causes the check engine light to come on.
How to Troubleshoot Throttle Position Sensors
Follow these steps for troubleshooting the throttle position sensors.
- Ensure that there is an accurate connection between TPS and ECU and there is no corrosion on the connections of wires.
- Check the voltage output of TPS through the use of a multimeter, and voltage increases must be uniform when the throttle is opened.
- Do a proper inspection of sensors for finding any damage; if there is any damage, replace it.
- If the throttle has dust particles on its surface, it can affect the reading of the TPS. So clean the surface properly for getting good signals.
- If performing all steps, your TPS is not working well; needed to replace it or use high-quality modules.
Where to install the throttle position sensor
- The throttle position sensor is connected to the throttle body, and through a change of the throttle opening and the throttle shaft rotation, the sensor moves, and the angle signal of the throttle opening is transformed into an electrical signal and provided to the ECU.
- Vehicles that have an automatic transmission normally come with a linear output throttle position sensor.
Throttle Position Sensor Adjustment Techniques
Follow these steps.
- Loosen the two fixed screws of the throttle position sensors.
- Use the thickness gauge of 0.35 mm between the throttle limit screw and the limit rod, and use a multimeter to measure the idle switch continuity.
- Move the throttle position towards anticlockwise for disconnection of the idle switch contact and turn the throttle position sensor clockwise till the idle switch is closed.
- Strongly tighten the two fixing screws of throttle position sensors.
- With the use of 0.30 mm and 0.40 mm thickness gauges for throttle limit screws and limit rods, respectively, and measures the condition of the idle switch.
- For the 0.30 mm thickness gauge, the idle speed switch is turned on, and for the 0.40 mm thickness gauge, the file speed switch is off.
Reset Process for Throttle Position Sensor
- Some years ago, TPS used a multimeter for measuring the value of the sensor output when the sensor was losing itself and turned it on the mounting pad for getting a certain output value.
- The simple method for resetting the sensor is to unhook the negative cable at the battery for 5 minutes, or you can remove the fuse for the engine control module.
- Resetting the mean restoring of the sensor. Code errors can affect the throttle position sensor for faulty results. You can get the services of a professional for reprogramming the sensor.
- Modern techniques are that off the ignition key and ON when pushing the gas pedal to the floor in the proper sequence. Some needed diagnostic devices for interfacing with the onboard computer.
- Throttle recalibration techniques are also used for sensor resetting.
Application of throttle position sensors
Gasoline vehicles:
- Gasoline engines use throttle position sensors for controlling field injection and ignition timing. It helps to provide good working features for the engine in different conditions.
Diesel vehicles:
- There is not direct use of throttle control in diesel engines, but throttle position sensors are used for monitoring intake volume and help to control fuel injection as ignition timing.
Motorcycles:
- In motorcycles, throttle position sensors are also used for controlling and increasing engine work and also provide good fuel efficiency.
Racing cars:
- Racing cars also use this sensor for providing high accuracy and good response for getting good output power and good performance.
Hybrid vehicles:
- There is no control of the internal combustion engine component in hybrid vehicles; also, work with the control system for getting smooth switching for motors and internal combustion engines.
FAQs.
What is the result when the throttle position sensor gets faulty?
- IF TPS is getting bad, then the throttle body of the car does not work well. It can be either off or not accurately close, which can cause the main problem. If it is shut, the engine is not getting air and will not start.
Can we drive vehicles with a bad throttle body sensor?
- No, it is not safe to drive a car with a bad throttle. If you note that it is going to be bad then instantly solve its issue. If not solved, vehicles can stall or not move.
How to find out if TPS is bad?
- At the time of normal driving, check the sensor if there are facing issues like hesitation at the time of acceleration or bad power that can cause a delay in gear shifting.
Can a car move without a throttle position sensor?
- Yes, the car can move without throttle position, but its working performance will not be as with the sensor. In case of absence of TPS, ECU will operate in default mode with the use of predefined settings for fuel injection and ignition timing.
What is a function of the throttle position sensor?
- The main function of the throttle position sensor is to give details about the position of the gas pedal to the ECU, like the throttle opening.
How to make sure if the throttle pedal position sensor is bad?
- The vehicle is not responding well or not accelerating properly at the time of acceleration.
- Output power is not stable.
- The fault indicator will be on.
- For finding fault, use diagnostic tools.
Can the throttle sensor be cleaned?
- In some conditions, the throttle position sensors are cleaned, but based on the design and location of the sensor. Cleaning of sensor solver issues of poor contact resulting from dust or grease and restoring to normal working.
- Make sure that not all sensors are best for cleaning, and faulty cleaning techniques cause damage to the sensor.
What causes a throttle control sensor to go bad?
- Dust particles, dirt, and oil accumulated on the sensor, that affects its accuracy and working features. If wearing connections are not made accurately, corrosion on connections also affects signal flow between TPS and the ECU.
How can I test my throttle position sensor?
- First of all, set the multimeter at the resistance value in the kilohm range.
- Then choose any 2 TPS pins for resetting and place probes so they are properly connected with pins.
- Set TPS to full range and measure the resistance value.
- Check that the resistance does not change throughout TPS movement.
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