How to Fix P0722 Code: A Guide to Fixing the Output Speed Sensor

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man testing the speed sensor

If you're getting the P0722 code on your car, don't worry because this is a common code that pops up on the OBD scanner. This guide will walk you through the steps to fix it. We'll discuss what might be causing the code and prevent it from happening again. Read on!

What is Code P0722?

The P0722 code is a generic powertrain Diagnostic Trouble Code (DTC) and applies to OBD-II vehicles. This is defined as "Output Speed Sensor No Signal." The role of the Transmission Output Speed Sensor is to provide the Powertrain Control Module (PCM) with readings that indicate the speed of the transmission output shaft rotation. 

The PCM uses these readings to calculate engine load and affect fuel delivery. When the PCM detects a malfunction within the Output Speed Sensor Circuit, a different P0722 can be triggered.

Symptoms of Code P0722

As the Output Speed sensor malfunction, the PCM will not correctly calculate engine load, which will affect fuel delivery. In that case, you will start to experience some of the symptoms below:

  • Check engine light illuminated.
  • Vehicle exhibiting signs of a slipping transmission such as jerking, hesitation, or lack of power
  • Transmission fluid levels dropping rapidly
  • Engine stalling
  • Engine misfiring
  • Stalling when idle
  • Stalling when driving at a high speed

Causes of Code P0722

Because the code P0722 is associated with many symptoms, many different causes can trigger it. Here are some of the most common:

  • A faulty output speed sensor
  • Input speed sensor / TSS sensor could not be working properly.
  • Failed transmission temperature sensor
  • Broken or loose connectors
  • Frayed or shorted wiring
  • Damaged PCM or TCM

How to Diagnose Error Code P0722

When diagnosing the P0722 code, it is crucial to do it step-by-step and systematically. It could be challenging, but you can try a few easy methods to diagnose this code yourself. Here are some easy steps you can follow:

Scan for Other Codes

Before anything else, you need to scan the system for other codes stored in the PCM. This will give you a better idea of what might happen and help rule out other potential issues.

A Quick Visual Inspection

Begin by visually inspecting the wiring. Ensure all connectors are correctly attached and no visible damage to the wiring. Check loose or damaged connectors.

Check Output Speed Sensor Signal

The next step is to check if the output speed sensor signal is average. Disconnect the output speed sensor connector and test the voltage between the two terminals using a digital voltmeter. It should produce a steady voltage of around 0.45 to 0.55 volts.

How to Fix Code P0722

If you're getting no signal, you might need to perform components replacement. Here are the possible fixes that you may try:

  • Replacing the output speed sensor
  • Replace the transmission fluid and the filter.
  • Repair leaks in the transmission fluid.
  • Flashing the PCM

Step-by-step Guide to Replacing the Output Speed Sensor

  1. The first thing you need to do is park your car and raise its front until enough space is beneath it to crawl.
  2. Locate the speed sensor. It's located on the bottom of the transmission and has a tiny plug sticking out with an electrical connection attached.
  3. Remove the electrical connector from the sensor. While pulling out the connector, continue to squeeze it.
  4. Grasp and twist the sensor counterclockwise until it comes free. Remove the sensor from the gearbox.
  5. Remove the old sensor from its mounting location.
  6. Twist the sensor clockwise until it is secure and does not turn further.
  7. Connect the electrical connector to the appropriate plug on the sensor, and you're done!

Step-by-Step Guide to Replacing the Transmission Fluid and the Filter

  1. Let your car idle for a few minutes because the transmission fluid drains better at operating temperature. 
  2. Turn off your ignition.
  3. Locate the transmission fluid drain plug on the underside of your car, near the front of the engine. 
  4. Place a pan beneath it to catch the draining fluid – most pans will come with an adapter to fit this drain plug specifically. 
  5. Slowly loosen the other bolts to allow the pan to tilt and begin to drain. After removing the bolts, lower the pan and pour any remaining liquid into the catch pan. If required, use a screwdriver to break the gasket seal gently.
  6. Clean the pan and transmission housing gasket surfaces. Examine the pan for metal shavings or other indications of internal damage, then clean it with solvent.
  7. Remove the old transmission filter and O-ring. You would need to drain the fluid in the filter into a pan beneath it.
  8. Install the new transmission filter, ensuring that its O-ring seats are in the right place.
  9. Apply a light coat of transmission fluid to the new O-ring, then install the pan and bolts. Tighten the bolts evenly in a crisscross pattern.
  10. Refill the transmission fluid according to your vehicle's owner's manual. Start the engine and check for leaks.

Step-by-Step Guide to Repairing Transmission Fluid Leak

  1. Locate the source of the leak. The location of a transmission leak is sometimes difficult to spot. One of the most effective methods to find out where a leak originates is to start with a clean slate. Clean the vehicle's entire underside using a degreaser or brake cleaner.
  2. Once the transmission fluid leaks have been identified, it's time to drain the fluid. Place a pan beneath the transmission and remove the drain plug using a socket wrench. Be sure to have a replacement gasket before reinstalling the drain plug.
  3. If the fuel lines are old, brittle, or damaged, it's best to replace them.
  4. Replace the complete line rather than attempt to repair it. You may splice in a new section of hose (on a low-pressure return line), but hose clamps and a little tubing will not endure long.
  5. If your leak is originating from a pressurized cooler line (the ones with the metal ends), you'll have to replace the whole line. However, properly seat the small rubber o-rings before tightening the fittings. Otherwise, you'll have another leak.
  6. Clean off any old gasket remains and replace them with a new one if you've already removed the pan and drained the fluid. It's also good to change your transmission filter while you're at it.
  7. If your transmission pan has been damaged, you'll need to replace it. Simply remove the old one and replace it with the new one.
  8. Install the new seal. Remove the remains of the old seal and replace it with the new one. Make sure the new seal is seated correctly. Otherwise, you'll have to disassemble everything again.
  9. The transmission leak can also be worn-out/loose pan bolts or drain plugs. If you discover a loose fastener or plug, the bolt might have worn threads, and a bumpy road jarred it loose. Install a new bolt and be cautious not to harm or crush the gasket.

Common Mistakes When Diagnosing the Code P0722

When diagnosing this error code, it's important not to jump to a conclusion, so you can correctly identify the issue. However, some people can't avoid making mistakes, especially when the issue is serious. Here are a few of the most common mistakes:

  • Assuming the problem is with the transmission when it might be an issue with another component such as the engine or wiring
  • Not being able to identify the source of the problem properly
  • Replacing the transmission sensor without proper tools.

Code P0722 FAQs

1. Is the P0722 code serious?

The P0722 diagnostic trouble code is serious. If you have this DTC, there's an issue with the output speed sensor of your transmission. This can cause shifting problems and eventually lead to failure if left unchecked.

2. Can I drive with this code?

If your vehicle displays the P0722 code, you should not drive it. Driving with this code can cause further damage to your transmission and lead to complete failure.

3. What can I do to prevent this code from coming back?

You can prevent the P0722 code from returning. Ensure that your transmission fluid is clean and at the correct level, and have your vehicle's speed sensor checked for proper function. If there is an issue with the sensor, it will need to be replaced.

4. How much does it cost to fix the P0722 code?

If you take your vehicle to a mechanic, they will charge you for the cost of diagnosis and repair. The average price for this service is between $100 and $200.

5. Do I need to use a unique tool to diagnose this code?

No, you do not need a special tool to diagnose this code. However, if you are going to be doing the repairs yourself, you will need a few basic tools and an OBD scanner.

Conclusion

If you're experiencing the P0722 code on your vehicle, it is vital to address it as soon as possible. The code is associated with many causes and manifests various symptoms that will worsen over time if left untreated. 

The good news is that there are many ways to diagnose and repair this problem independently. We hope this guide has given you the information and confidence to fix the P0722 yourself! If you have any questions about diagnosing and repairing other error codes, just leave your comment below!