There can be several symptoms of a bad throttle position sensor in a vehicle. In modern vehicles, various types of sensors are used for better performance of engine parts, which send data signals about the working condition of various parts of the vehicle to the engine control module of the vehicle.
Similarly, the throttle position sensor is an important sensor that sends a signal to the ECM about the position of the throttle butterfly in the vehicle’s engine, from which the ECM determines the fuel mixture and proper ignition for better engine operation. But sometimes the throttle position sensor fails to work properly or stops working altogether.
In this article, we will learn about the throttle position sensor in detail. Such as what is a throttle position sensor, symptoms of a bad throttle position sensor, and how much does the replacement cost?
What Is A Throttle Position Sensor?
The throttle position sensor is the component that sends a signal to the ECM about the opening and closing position of the throttle butterfly used in the engine, and based on this data, the ECM determines the proper fuel mixture and ignition for better operation of the engine. Whether the engine is idling or accelerating,
When the accelerator pedal is pressed. Then the actuator on the throttle body of the engine opens, due to which the engine accelerates. The throttle position sensor informs the ECM about the position of the actuator on the throttle body, after which the ECM determines the correct ratio of air and fuel in the fuel mixture for the engine based on this signal.
Symptoms Of A Bad Throttle Position Sensor
Common symptoms of a faulty throttle position sensor may include erratic engine performance, engine stalling, acceleration problems, poor fuel efficiency, rough idle, or sudden changes in speed. In some cases, hesitation, loss of power, or jerking may be experienced during acceleration.
A bad TPS can disrupt communication between the throttle and the engine control unit, causing these performance problems. Let us learn about these symptoms in detail.
1. Check Engine Light On
In modern technology vehicles, the main symptom of any sensor or electrical fault is the illumination of the check engine light in the cluster meter.
A bad or damaged throttle position sensor is unable to report valve position to the throttle body or gives incorrect readings. Due to which the ECM of the vehicle first indicates as a warning the check engine light.
2. Engine Jerks During Acceleration
A bad or damaged throttle position sensor can result in engine jerking during acceleration. Because the throttle position sensor is unable to inform the ECM of the valve position of the throttle body during acceleration, the ECM is unable to determine the correct ratio of air and fuel in the fuel mixture of the engine, due to which the engine starts jerking during acceleration.
3. Rough Idle Issue
A bad or damaged throttle position sensor will often cause the engine to start in a rough idle position, due to which the engine RPM suddenly starts decreasing or increasing when the engine is running at idle or the engine starts over-accelerating many times.
4. Hesitation Acceleration
Often, the engine starts to hesitate during acceleration if the throttle position sensor is bad. Because a bad throttle position sensor does not inform the ECM of the actual position of the valves in the throttle body.
As a result, the ECM is unable to determine the correct ratio of air and fuel in the fuel mixture for the engine. The fuel is not supplied to the engine as per the requirement for acceleration, and the engine hesitates during acceleration.
5. Loss Of Engine Power
A poor throttle position sensor may result in a reduction in engine power performance. A bad position sensor is unable to inform the ECM of the actual position of the valves on the throttle body. Due to this, the ECM is not able to supply fuel according to engine acceleration.
Due to this, a reduction in the power performance of the engine can be felt. Because of the poor fuel-air ratio and low volume, the fuel combustion action in the internal combustion chamber of the engine is disrupted.
Causes Of A Throttle Position Sensor Failure
- Bad or damaged throttle position sensor
- Damaged throttle position sensor wiring
- Incorrect adjustment of throttle position sensor
- Throttle body leaks or wear
- Faulty Engine Control Module
- Bad Timing Chain Adjustment
How To Fix Throttle Position Sensor
In order to fix the fault of the throttle position sensor, you must investigate its cause. such as
First of all you have to scan the system of the vehicle with OBD scanner. so that you can know about the actual fault of the vehicle.
- Then try changing the position of the throttle position sensor.
- Check the reading of the throttle position sensor.
- Check the wiring to the throttle position sensor.
- Also check for air leaks from the throttle body.
- Replace the bad or failing throttle position sensor with a new one.
- Lastly, you can also check the engine control module.
How Does Throttle Position Sensor Work?
The throttle position sensor sends information about throttle valve opening to the vehicle’s engine control module, and based on the signal from this sensor, the ECM controls the firing sequence of the fuel mixture into the engine through the fuel injectors.
When the engine is accelerated. Then the valve in the throttle body of the engine opens according to the acceleration, and air enters the engine according to the opening of the valve in the throttle body. This sensor sends information about the opening and closing positions of the throttle butterfly to the ECM.
Based on this information, the vehicle’s ECM determines the ratio and amount of air and fuel in the fuel mixture to be sent to the engine and accelerates or decelerates the ignition timing according to the required acceleration.
Throttle position sensors are often three-wire or pin. The one-wire sensor comes with a 5-volt mains supply. One wire is a ground connection, and the third wire carries the output signal from the sensor to the ECM.
Throttle Position Sensor Location
Often, the throttle position sensor is located on the throttle body of a vehicle’s engine. where in the throttle position sensor monitors the position of the valves on the throttle body.
Mechanic’s Mistake In Throttle Position Sensor Diagnosis
Mechanics often mistake the symptoms of a failing throttle position sensor for other faults. Instead of checking the throttle position sensor or making position adjustments, the first thing the mechanic does is replace the fuel injector or spark plug.
Because the symptoms of all these reasons can be similar, Therefore, when this happens, the air leak from the throttle body should be checked.
Throttle Position Sensor Replacement Cost
Throttle position sensor replacement cost depends on the type of sensor and the mechanic’s labor costs.
On average, throttle position sensor replacement costs in typical cars can range from $175 to $240, including mechanic labor costs. This estimated cost does not include taxes and fees.
A throttle position sensor can cost between $120 and $160, and mechanic labor costs can range from $55 to $80.
However, if you replace the throttle position sensor yourself, you can save on paying a mechanic’s labor costs.
Q. What does the throttle position sensor do?
The throttle position sensor sends information to the ECM about the actual valve opening position of the engine’s throttle body. The throttle body controls the air and sends it to the engine’s intake manifold.
Q. How do you reset the throttle position sensor?
You can use an OBD digital scanner to reset your throttle position sensor. Or you remove the main wire from one terminal of the battery for some time or the ECM fuse may be blown. But in some expensive and very modern vehicles, removing the battery supply may reset the entire system memory data from the ECM.
Banty is the owner of Autorepairszone.com & is also a vehicle mechanic by profession. We have almost 12 years of experience in the field of automotive repair, and we strive to provide you with accurate information about vehicle malfunctions and repairs based on our experience.