Prius Inverter Pump Failure Symptoms: Identify and Address

As a Prius owner, it can be frustrating when your vehicle suddenly starts to experience issues. One common problem that can occur is inverter pump failure, which can cause a wide range of symptoms and affect the overall performance of the car. 

However, identifying and resolving this issue can help prevent further damage and ensure your Prius continues to run smoothly. In this article, we will discuss the common symptoms of Prius inverter pump failure, how to check for it, and provide tips on how to prevent it from happening in the future. 

We will also answer some common FAQs about inverter failure and replacement cost to help you better understand this important component of your hybrid vehicle.

What Is The Purpose Of The Inverter Pump in a Prius? 

In a Prius, the inverter pump serves an essential purpose in the hybrid inverter cooling system. This cooling system is responsible for regulating the temperature of the power module, a critical component that converts the direct current (DC) generated by the hybrid battery into alternating current (AC) to power the electric motor.

The inverter pump circulates coolant through the hybrid inverter cooling system, specifically the boost converter and the DC converter. 

The boost converter increases the voltage output of the hybrid battery to power the electric motor, while the DC converter regulates the flow of electricity from the hybrid battery to the electric motor.

The inverter pump works in tandem with the radiator and the electric fan to maintain the appropriate temperature for the power module. 

In doing so, it helps to prevent the inverter converter from overheating, which can cause significant damage to the hybrid battery and other critical components.

Prius Inverter Pump Failure Symptoms

The inverter pump in a Prius is a critical component of the hybrid inverter cooling system. If it fails, it can lead to significant problems with the vehicle’s performance and potentially cause damage to other important systems.

Here are some of the most common symptoms of inverter pump failure in a Prius:

  1. Overheating

The inverter pump is responsible for regulating the temperature of the power module. When it fails, the power module may overheat, which can cause the vehicle to enter a “safe mode” and limit its performance.

  1. Check Engine Light

A malfunctioning inverter pump can trigger the check engine light to come on. If you notice this warning light on your dashboard, it’s essential to take your vehicle to a qualified mechanic to diagnose the issue.

  1. Triangle Warning Light

Another warning sign of inverter pump failure is the triangle warning light. This light indicates a problem with the hybrid system, and it’s crucial to get the vehicle checked immediately.

  1. Loss of Power

If the inverter pump is not functioning correctly, it can cause a loss of power to the electric motor. This loss of power can make it challenging to accelerate and maintain speed while driving.

  1. Strange Noises

If you hear unusual sounds coming from your vehicle, such as whining, buzzing, or clicking, it could be a sign of a failing inverter pump.

How To Check A Prius Inverter Pump

Here’s a brief step-by-step process to check the inverter pump in a Prius:

  1. Turn off the engine and allow the vehicle to cool down for at least an hour.
  1. Open the hood of your Prius and locate the inverter pump. It is typically located on the passenger side of the engine compartment and is identified by a blue cap.
  1. Carefully remove the blue cap, and check the coolant level inside the inverter pump. If the coolant level is low, it may be a sign of a leak or a failing inverter pump.
  1. Inspect the inverter pump for any signs of damage or wear, such as cracks or leaks. If you notice any damage, it’s best to have the pump replaced as soon as possible.
  1. If you have access to a diagnostic tool, you can also check the inverter pump’s performance by monitoring the coolant temperature and flow rate. This will give you a better idea of whether the pump is functioning correctly.
  1. If you are not confident in your ability to check the inverter pump yourself, it’s best to have a qualified mechanic inspect the vehicle.

What Happens When Inverter Pump Stops Working?

When the inverter pump in a Prius stops working, it can cause several issues that can affect the vehicle’s performance and safety. 

The inverter pump is responsible for cooling the hybrid inverter and converter, which are critical components of the vehicle’s hybrid system. Without proper cooling, these components can overheat and fail, which can result in reduced power, poor fuel efficiency, and even engine damage. 

Additionally, a failed inverter pump can trigger warning lights on the dashboard, such as the check engine light, and may even cause the vehicle to enter into “limp mode,” where it is unable to accelerate or operate at full power. 

If you suspect that your inverter pump is not working correctly, it’s important to have it inspected and repaired as soon as possible to prevent further damage.

What Is The Cause Of Inverter Failure?

Here are some possible causes of inverter failure in a Prius:

  • Overheating

One of the most common causes of inverter failure is overheating. If the inverter and converter are not adequately cooled, they can overheat and fail, which can cause serious damage to the hybrid system.

  • Leaks

If the inverter pump or any other component of the hybrid cooling system develops a leak, it can cause a loss of coolant, which can lead to overheating and component failure.

  • Wear and tear

Over time, the inverter and other components of the hybrid system can become worn and damaged, which can cause them to fail.

  • Electrical issues:

The high-voltage electrical components of the hybrid system, including the inverter, are vulnerable to electrical surges and other issues that can cause damage.

  • Corrosion

Corrosion or other forms of damage to the metal components of the inverter or other parts of the hybrid system can cause failure.

  • Improper maintenance

Failure to perform regular maintenance on the hybrid system, such as changing the coolant and inspecting the inverter pump, can lead to inverter failure and other issues.

  • Manufacturing defects

In some cases, inverter failure may be caused by defects or design flaws in the original equipment.

Tips to Prevent Inverter Pump Failure In a Prius

Here are some tips to prevent inverter pump failure in a Prius:

  1. Regular maintenance

Regular maintenance is essential to keeping your Prius running smoothly and preventing inverter pump failure. Be sure to follow the manufacturer’s recommended maintenance schedule and have your vehicle inspected regularly by a qualified mechanic.

  1. Keep the cooling system in good condition

The inverter pump is part of the hybrid inverter cooling system, so it’s essential to keep this system in good condition to prevent inverter failure. Keep an eye on your coolant levels and have your cooling system inspected regularly.

  1. Avoid overloading the vehicle

Overloading your vehicle can put extra strain on the hybrid system, including the inverter pump, which can cause it to fail more quickly.

  1. Avoid harsh driving

Harsh driving, such as rapid acceleration and sudden stops, can also put extra strain on the hybrid system and lead to inverter pump failure.

  1. Avoid extreme temperatures

Extreme temperatures, both hot and cold, can also cause inverter pump failure. Try to park your vehicle in a covered area and avoid driving in extreme weather conditions whenever possible.

Can An Inverter Be Repaired?

In some cases, an inverter can be repaired, depending on the extent of the damage. However, in most cases, it’s more cost-effective to replace the inverter rather than attempting to repair it. 

If you suspect that your inverter is malfunctioning, it’s essential to have it inspected by a qualified mechanic or a certified Toyota technician to determine the best course of action. 

They can diagnose the issue and provide you with recommendations for repair or replacement.

Prius Inverter Replacement Cost

The cost of a Prius inverter replacement can vary depending on several factors, including the make and model of your vehicle and the extent of the damage. 

On average, the cost can range from $2,500 to $4,000, including parts and labor. It’s essential to have your inverter inspected by a qualified mechanic or certified Toyota technician to determine the extent of the damage and get an accurate estimate for the replacement cost. 

In some cases, it may be more cost-effective to replace the entire hybrid system rather than just the inverter.


What is the average lifespan of an inverter?

The average lifespan of a Prius inverter is around 150,000 miles. However, it can vary depending on several factors, such as the vehicle’s usage and maintenance.

Can a faulty inverter drain battery?

Yes, a faulty inverter can drain the Prius battery. When the inverter malfunctions, it can cause the battery to drain faster, which can lead to other issues such as reduced performance and frequent check engine lights.

How long can inverter run continuously?

Most inverters are designed to run continuously for up to eight hours. However, it’s important to check the manufacturer’s instructions to determine the specific run time for your inverter.

Can overcharging damage inverter battery?

Yes, overcharging can damage the inverter battery, causing it to lose its capacity and ability to hold a charge. 
It’s important to follow the manufacturer’s guidelines for charging and to avoid leaving the battery connected to the charger for an extended period.

How much electricity does an inverter use per hour?

The amount of electricity used by an inverter per hour can vary depending on the size and type of inverter. 
However, on average, a small inverter can use between 1-2 amps per hour, while a larger inverter can use between 5-10 amps per hour.

Final Thoughts

The inverter pump is a crucial component of a Toyota Prius that ensures the smooth functioning of the hybrid system. Any issues with the inverter pump can result in a range of symptoms that can affect the overall performance of the vehicle. 

By being aware of the common signs of inverter pump failure and taking steps to prevent it from happening, you can help ensure that your Prius runs smoothly for years to come. 

If you do experience issues with your inverter pump, it is important to seek professional help to diagnose and repair the problem. 

By doing so, you can save money in the long run and avoid further damage to your vehicle.

Ricardo Vaughn
Ricardo Vaughn

Vaughn is a seasoned off-roading expert and professional winch specialist. When he's not out on the trails, he shares his knowledge and experiences through his writing as a blog author in the off-roading and outdoor lifestyle space.

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