engine speed sensor

After purchasing or leasing your new Lexus from Earnhardt Lexus, it makes sense that you would want to know what keeps your beautiful automobile in top condition.  Part of the answer relies on the engine control unit (ECU) and the sensors it monitors throughout your engine. One of the most important is the engine speed sensor.

It is important to pay attention to how your car works and be ready if you notice something is wrong.  Regardless of the make or model, you can schedule a certified auto repair with us.  Our mechanics have the tools and equipment needed to make exacting repairs on any type of car or SUV.

What is the Engine Control Unit

You can think of the ECU as the brain of your car.   There are a number of sensors in your new Lexus that communicate with the engine control unit (ECU) or engine control module (ECM) to keep your auto working at optimal capacity. The ECU regulates four main parts of your Lexus systems: air-fuel ratio, idle speed, variable valve timing, and ignition timing. Some of the sensors in your Lexus include mass airflow sensors, oxygen sensors and air-fuel sensors. 

What is the Engine Speed Sensor?

The engine speed sensor, also known as the transmission speed sensor, is one of the sensors that communicates with the ECU to keep your Lexus in great running condition. The engine speed sensor’s job is to calculate the speed at which the wheels are rotating, ultimately determining the speed you are traveling. 

Where is the Engine Speed Sensor and what engine light corresponds to it?

The sensor is located on the car's transmission and this is why it is sometimes called the transmission speed sensor. It sends information to your speedometer and your engine’s computer to tell the transmission when to shift. If the speedometer in your Lexus isn’t working, or there’s a check engine light that accompanies shifting problems, be sure to let a Earnhardt Lexus technician examine your vehicle.

Lexus vehicles get good safety ratings, but if they aren’t functioning properly, travel may become dangerous.  It is important to your car safety that you don’t ignore check engine lights.  By the time these lights are on, the problem has become significant and may be harming other components of your vehicle.

How does the Engine Speed Sensor Work?

Engine speed sensors calculate the gear ratio of the transmission while the car is being driven. Usually there are two speed sensors working together to provide accurate data to the ECU. One is the input shaft speed sensor and the other is the output shaft speed sensor. 

The function of the input shaft speed sensor is to keep track of the transmission’s input shaft speed. The gears of the transmission allow you to reduce the speed of the wheels so that they are not always going as fast as the engine’s speed. Then the output shaft goes to work because it is linked to the drive wheels and changes speed based on the gear you select.

The output shaft speed sensor detects the speed of the drive wheels and sends this information to the ECU. Together they allow the wheels to rotate at a speed that is manageable while the engine continues to run at a speed that makes it perform efficiently. This would not be possible without your engine speed sensors.  

If you have any questions regarding the engine speed sensor in your Lexus, please contact Earnhardt Lexus or our service department to learn more. We have experts on hand to help with all of your Lexus needs! 



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