If your vehicle is showing code P0720, this indicates a problem with your output speed sensor circuit. This means your vehicle’s computer has detected a problem with the sensor that helps it control the way the vehicle shifts gears. Since there are usually performance problems related to this error, you will want to fix it as soon as possible.

An OBD-II trouble code reader checks your car’s computer and can tell you about certain problems by giving you a diagnostic trouble code (DTC).
Error code P0720 indicates an issue with your output speed sensor circuit.
You may want to seek out the help of an expert to identify the specific cause(s) of a P0720 engine code.

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What does the engine code P0720 mean?

A P0720 code—defined as Output Shaft Speed Sensor Circuit Malfunction—indicates an issue with your output speed sensor circuit.

This sensor measures how fast the vehicle is moving and sends messages to the transmission to tell it when to shift gears.

How much will it cost to fix the problem?

Costs vary depending on the cause of the P0720 code.

For example: Draining and

replacing transmission fluid

professionally generally costs between $240–$290. On the other hand, replacing an output speed sensor will likely cost somewhere between $330–$380.

The cost of replacing an outspeed speed sensor will depend on the make/model of your vehicle. Parts for high-end vehicles, for instance, can run around $265.

What can cause the P0720 engine code?

There are a variety of causes for a P0720 output speed sensor circuit malfunction, some of which are easier to address than others:

Low or dirty transmission fluid

Faulty output speed sensor or input speed sensor

Wiring problems

Defective PCM (powertrain control module) (rare)

Common symptoms of the P0720 engine code

Your first sign that you could have a problem related to a P0720 fault code is an illuminated check engine light.

In addition, drivers will likely notice one or more of these symptoms:

Car is hard to shift

Bad fuel economy

General drivability problems

Performance issues such as

stalling out

or engine misfires

Malfunctioning speedometer

How serious is the P0720 code?

Because problems related to a P0720 code directly affect the operation of your vehicle, you will want to fix any underlying problems as soon as possible. If you ignore these issues, you can damage your transmission.

Can I fix the P0720 engine code myself?

Depending on the cause of the error message, you may be able to clear a P0720 yourself. What follows are two common DIY projects you might want to undertake. Always refer to manuals for your specific vehicle’s

make and model

Changing transmission fluid

Warm the engine

If the engine is cold, let it warm up so that the fluid will drain better. Be sure to park your vehicle on a level surface. Then, be sure to turn the engine off.

It is easier to drain your transmission fluid if the vehicle is up on a lift and level. However, if you do not have access to a lift, you will have to use jack stands to raise the vehicle so that you can get underneath it. Be sure to use wheel chocks to secure the back wheels.

Lay down a protective tarp or cardboard and a drain pan underneath the transmission to catch the old transmission fluid.

Drain the old transmission fluid

Remove the bolts from one side of the transmission pan, making sure that the old fluid is draining into the drain pan. Remove the bolts from the other side and break the gasket seal.

After removing the transmission pan, clean the surfaces on both the pan and the transmission housing.

Inspect the fluid that has drained into the drain pan to make sure there are no metal shavings. If there are, this may indicate internal damage to the transmission.

Install the new gasket, filter, and O-ring

Carefully remove the old transmission filter and O-ring. Then, install the new filter and O-ring.

Using oil-soluble grease, attach a new gasket to the transmission pan.

Attach the transmission pan back onto the transmission, being careful to follow the direction in your manual about maximum torque recommendations.

Add new transmission fluid and check for leaks

Lower the vehicle and then fill your transmission with the recommended amount of transmission fluid.

Re-start your vehicle and check for leaks.

Replacing a faulty output speed sensor

Park your vehicle on a level surface and use jack stands to raise the car high enough in the front to get underneath it. Use wheel chocks to secure the back wheels.

Locate the output speed sensor, which should be located on the bottom of the transmission. This sensor—which looks like a plug—is connected to an electrical connector.

Disconnect the electrical connector to get at the speed sensor. Then, use a wrench to loosen the sensor and remove it. Replace with a new sensor.

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