What Does a Output Speed Sensor Do

A vehicle’s output speed sensor is an electronic device that measures and monitors the rotational speed of the transmission. This part is typically found on vehicles with automatic transmissions, and it helps the car’s computer determine when to shift gears for optimal performance. The sensor works by measuring a gear or wheel rotation within the transmission and sending a signal back to the Electronic Control Unit (ECU).

Based on this data, as well as other inputs from sensors around the engine, such as throttle position and RPMs, it will tell the computer when it should upshift or downshift based on whether you are accelerating or decelerating. By doing so, it helps ensure your vehicle runs smoothly with maximum fuel efficiency in any given driving condition.

A output speed sensor is a crucial component in any vehicle’s transmission system. It monitors the rotational speed of the transmission output shaft and sends feedback data to an on-board computer, which then adjusts the shifting pattern of the transmission based on that information. This helps ensure your vehicle runs smoothly and efficiently while also helping to protect it from potential damage due to over-revving or under-revving the engine.

Difference Between Vehicle Speed Sensor and Transmission Speed Sensor

What Happens When Output Speed Sensor Goes Bad?

An output speed sensor, also known as an OSS or a vehicle speed sensor (VSS), is an important component of any vehicle’s transmission system that ensures the proper functioning of the engine. If your output speed sensor goes bad, it can cause all sorts of problems with your car’s performance and handling. When the output speed sensor fails, it will send incorrect information about the rotation rate of your wheels to the transmission control unit.

This can result in jerking or lurching when you accelerate from a stop due to erratic shift points; this may also manifest itself as poor fuel economy and poor acceleration even at higher speeds. In addition, if there is no output signal from the OSS then cruise control will not be able to maintain constant speeds accurately either because without input data on wheel RPMs cruise control cannot act accordingly. Ultimately, a faulty output speed sensor means that your car won’t run properly and you need to get it fixed as soon as possible so that you don’t have these issues down the line.

Can You Drive With a Bad Output Speed Sensor?

No, it is not wise to drive with a bad output speed sensor. This component helps the transmission control module (TCM) determine how fast your vehicle’s engine and transmission are operating. The TCM uses this information to regulate shift points, fuel economy, and other performance-related functions.

If your output speed sensor fails or begins to malfunction, you may experience erratic shifting patterns along with symptoms such as reduced acceleration, increased fuel consumption and hard starts. In some cases, these issues can be resolved without replacing the output speed sensor but most of the time it needs replacement in order for your car’s performance to return back to normal levels.

What is the Difference between Input And Output Speed Sensors?

Input speed sensors detect the rotational speed of an engine or other part, usually by measuring changes in voltage created as a result of the rotation. Output speed sensors measure the rotational speed at which power is delivered from one component to another, such as from a motor to a drive shaft or between two gears. Input and output speeds are related but distinct measurements and understanding both can help engineers design better working machines or optimize existing ones for improved performance.

Input speed sensors tend to be more precise than output ones because they measure at relatively low frequencies (RPMs) which allows for more granular readings. Output sensor readings on the other hand are typically higher frequency and therefore less accurate, making them most useful when monitoring overall system performance rather than individual components.

How Do I Know If My Transmission Speed Sensor is Bad?

If you suspect that your transmission speed sensor is bad, there are a few signs to look out for. One of the most common symptoms is erratic shifting or slipping into neutral when accelerating. This can be caused by inaccurate readings from the sensor which trick the transmission into thinking it needs to shift gears at an earlier time than necessary.

Another symptom is inconsistent engine speeds while driving and/or difficulty maintaining even acceleration in certain gears. If either of these situations occur, then it may be time to check your transmission speed sensor as there could be a problem with its wiring or connections. Additionally, if you find that your vehicle won’t move forward when put in drive, this could also be a sign of a faulty speed sensor since it sends information about wheel rotation to other components in order for them to work correctly.

Finally, some vehicles have dashboard warning lights that will alert drivers if their sensors need attention; so keep an eye out for any illuminated symbols on your dash!

What Does a Output Speed Sensor Do

Credit: www.amazon.com

Output Speed Sensor Symptoms

A faulty output speed sensor can cause a variety of symptoms in your vehicle, such as transmission slipping and a noticeable decrease in power. Your check engine light may also become illuminated, indicating an issue with the output speed sensor. Other common signs include abnormal shifts or jerking during acceleration and deceleration, as well as erratic changes in engine RPMs.

If any of these symptoms have appeared, it is important to get your car checked out by a professional mechanic to diagnose the problem and make sure that you don’t damage other parts of the vehicle’s drivetrain.

Difference between Input And Output Speed Sensor

Input and output speed sensors are two types of sensors used to measure the speed of an engine or motor. The input speed sensor is typically located on the crankshaft or camshaft, while the output speed sensor is usually located on one or both wheel hubs. The input speed sensor measures the rotational speed of a rotating device such as a shaft, while the output speed sensor measures how fast power is being transferred from one side to another.

Both of these sensors provide important information for controlling various functions like fuel injection and transmission operation.

How to Test Transmission Speed Sensor

To test a transmission speed sensor, you’ll need to use an oscilloscope and multimeter. First, connect the oscilloscope to the vehicle’s data bus. Next, start the engine and let it run until it reaches operating temperature.

Once this is done, set your multi-meter to measure voltage and place one of its probes on each side of the transmission speed sensor connector while having your other probe connected to ground. If there is no voltage present or if the reading doesn’t match what was expected based on factory specifications then you know that your transmission speed sensor needs replacing.


In conclusion, it is clear that the output speed sensor plays an important role in a vehicle’s transmission system. It helps to regulate the flow of power from the engine to ensure smooth and safe operation of a car or truck. Without it, many safety features would be compromised and long-term reliability would be at risk.

Therefore, if you ever experience problems with your vehicle related to shifting gears or acceleration, then make sure to have your output speed sensor checked out as soon as possible.


  • Alex Gearhart

    Alex Gearhart, an automotive expert specializing in transmissions, has over a decade of hands-on industry experience. With extensive knowledge in manual and automatic systems, Alex is passionate about educating car enthusiasts on vehicle maintenance. As the chief author at TransmissionCar.com, Alex simplifies complex concepts for readers, helping them make informed decisions about their vehicles. Outside of work, Alex enjoys road trips, restoring classic cars, and exploring new automotive technologies.

Leave a Comment