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Prius Check Engine Light Reset – How To? [Step By Step Guide]

You may want to reset the check engine light on your Prius but wonder how to go about it. Luckily, we have done some research for you, and here is what we found.

Do any of the following to reset the check engine light on your Prius:

  • Turn the ignition on and off
  • Employ the odometer approach
  • Use a scan tool
  • Remove the battery

Resetting the check engine light on your Prius is not as difficult as it seems. Keep reading to get detailed information on how to reset a check engine light.

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Toyota Prius C 2015 Test Drive on Jan 28 2015 in Hong Kong, Prius Check Engine Light Reset - How To [Step By Step Guide]

How To Reset Prius Check Engine Light

Follow this guide to reset the check engine light on your Prius:

Check engine light illuminated on dashboard.

Turn The Ignition On And Off

You can reset your Prius check engine light by turning the ignition on and off. To do this, insert the key into the ignition and try turning it on and off. Repeat this two more times. It is recommended to wait for one second after each round. Next, check if this method worked by driving the car for a while.

When driving, the computer system tries to examine the issue and offer a solution. If your engine check light goes off, know the reset is successful. But if you notice that it is still active, proceed to the next step.

Employ The Odometer Approach

This is another way of resetting your Prius check engine light. All you have to do is turn your car off and then insert the key in the ignition. After that, try holding down your brake pedal before pressing the power button. This will turn on your Prius. Locate the odometer trip button and press it while still pressing the brake pedal.

Next, turn your vehicle off and then on, but make sure you still have a hold of the brake and odometer button simultaneously. Check to see if the odometer on the digital display changes to dashed lines. If yes, you are on the right track. It should also begin a countdown.

The odometer is likely to flash "000000" when you notice that the dashes are on the right. Check to see if the light has reset as soon as it comes on again. If the check engine light fails to reset, consider the next step.

Use A Scan Tool

It is possible to reset your Prius check engine light using a scan tool. Get a scanner, locate the OBD connector and connect it. The OBD connector is usually found underneath the steering area.

Next, turn on your car and make sure it has a connection with the computer. Check the scanner for the read button and click on it. The main purpose of this is to get to all trouble codes present.

When you have finished with the scanning process, don't forget to save all error codes so you can determine the major issues with the help of your manual. If you can decode the code, then you are a few steps to solving the issue.

After determining the problem, try fixing it as soon as you can. If there is a need to replace any component, consider doing so. You can also consult a professional if you cannot do the replacement alone. 

The next step is to make the scanner error-free. Simply click on the "Erase/Clear" button to do so. After fixing the issue, consider turning the ignition off and on. This is to be sure that the engine check light is inactive. You can also examine the scanner to see if it has a similar or different fault.

Click here to view this OBD2 scanner on Amazon.

Remove The Battery

This is also an option when it comes to resetting your Prius check engine light. You have to take out the battery terminal for just a few seconds. With this, the engine control unit gets reset.

Take out the negative car battery terminal and press the horn for some time - 20 to 30 seconds should be fine. Alternatively, turn on your car's lights. Doing this will get rid of any electricity in your capacitor. When you are sure there is no electricity present, wait for about 10-15 min before attaching the battery terminal. 

Always double-check to ensure that they are connected properly; you don't want to entertain any spark. After that, you can turn on your vehicle. This should reset your check engine light.

In some cases, the check engine light could show up again after a few days or weeks. If you are experiencing such, it is recommended to consult a professional to help you with the problem.

Will Prius Check Engine Light Reset Itself?

Toyota Prius C 2015 Test Drive on Jan 28 2015 in Hong Kong.

It is possible that the check engine light won't reset itself until you solve the issue. Even after solving the issue, you may need to wait for a while before it resets itself. For a car to reset the check engine light, about 10-20 cycles are required.

A cycle refers to the period when a car is initially started and driven for a while till it warms up. This extends to when the car is parked and turned off. 

If you want your Prius check engine light to reset itself after several circles, make sure to solve the problem first. However, so much time may be needed to achieve 10-20 successful cycles.

Why Is My Prius Check Engine Light On?

Here are possible reasons why your Prius check engine light is on:

Bad Spark Plugs

Spark plugs work by igniting both fuel and air. With this, combustion is produced so the engine’s cylinders can function. If you have a bad spark plug, it can result in an engine misfire.

When this happens, the amount of hydrocarbon released will rise, and the engine may fail to work as it should due to this problem. This will cause your Prius check engine light to come on.

Defective Gas Cap

Exterior of car with fuel filler door open.

The gas tank system has lines and valves that help in distributing gas vapor so they won't get outside. A defective or loose gas cap can cause your Prius check engine light to come on. It can also make you spend a lot buying fuel because there is a chance for the fuel to evaporate. This may even affect the circulation of your fuel system.

Faulty Oxygen Sensor

The work of an oxygen sensor is to measure the oxygen in your exhaust. When the oxygen present is in excess or limited, other portions of the engine could be affected. However, a malfunctioning oxygen sensor will trigger the check engine light. This problem is usually the reason why the light becomes active, especially while the car is in motion.

Malfunctioning Catalytic Converter 

The catalytic converter helps in converting carbon monoxide into carbon dioxide. But when it starts to malfunction, chances are that your car will use up a lot of fuel. Also, your emission will rise, and passing the emission test becomes impossible. 

Getting a replacement may not solve the problem since the component usually goes bad as a result of head gasket-related issues. This can cause burnt coolant vapor to get into your exhaust. As a result, your check engine light becomes active.

What Happens if I Ignore the Check Engine Light?

Check engine light

It is not advisable to ignore the check engine light. When you notice that yours is active, the first thing to do is to determine if it comes on and off or is actually illuminated. If yours is flashing, chances are there is an internal issue with your car that should be dealt with as soon as possible.

Driving with illuminated check engine light causes your car to use a lot of fuel. Also, you may end up spending a lot on repairs. Most components in a car function together and when one goes bad, others get affected.

As a result, your vehicle will not work as it should. Whenever you see the check engine light, try your best to know why it is on.

To Wrap Up

To reset your Prius check engine light, you have to turn the ignition on and off, employ the odometer approach, use a scan tool, or remove the battery. Don't hesitate to contact a professional if the reset doesn't work.

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