Prius Wont Start Causes Fixes: A Comprehensive Guide

“Prius wont start causes fixes?” is a pressing query for most Prius owners once their car refuses to start. This can be alarming, especially if you’re not an automobile expert.

Prius Wont Start


In this article, our automobile team will explain the causes of this frustrating issue and how to fix it.

Why Is Your Toyota Prius Not Starting?

Your Toyota Prius is not starting because of issues such as a faulty fuse, rodent damage, engine failure, a defective spark plug, a clogged petrol filter, gas pump failure, faulty camshaft, insufficient battery charge, faulty alternator, missing engine coil, or a loose battery contact.

– Gas Pump Malfunction

If your Prius refuses to start, there’s a high chance you are dealing with a fuel pump failure. The pump is responsible for allowing the right amount of fuel to pass from the tank to the engine with sufficient pressure.
Reasons for a pump failure include a worn or contaminated pump, a broken pump lever, or a leaky pump. A pump failure will cause your car’s engine to turn over slowly or not start at all. When this is the case, your car won’t start.

– Spoilt Fuse

If you have a blown fuse, your Prius won’t start. The fuse box acts as a safeguard against voltage spikes. However, if too much voltage passes through the fuse, it can blow. This can destroy ignition circuits and prevent your car from starting.

– Worn-out Spark Plugs

Worn-out spark plugs are one of the common reasons why your car won’t start. These plugs play an essential role in your car ignition. If they are worn, they might not properly ignite the fuel. This will cause your Prius not to start.

One of the most prevalent problems associated with a defective spark plug is a misfiring engine. If your engine begins to misfire and refuses to start, you can be sure it’s from your spark plug.

– Damage by Animals

Rat and rodent damage can be another reason why your Prius won’t start. These animals crawl under the vehicle and bite through wires and connections. These bites can disconnect wires and affect all vehicle systems, including the power, oil, and fuel supply. Damage to any of these systems will prevent your car from starting.

– Engine Malfunction

Although it’s rare, engine malfunction or outright failure can prevent your car from starting. A failure of the engine leads to a failure of all car systems. The main causes of engine failure include incorrect fueling, overheating engine, and insufficient oil.

– Blocked Fuel Filter

Sometimes, your car may not start because you have a clogged fuel filter. The filter works like any other accessory in a vehicle, but it gets clogged by dirt and other contaminants over time. As a result, the permeability and pressure of the fuel drop.

Toyota Prius Not Starting


If the filter is blocked by contaminants, your car will not start. The dirt will obstruct the flow of fuel to your car’s engine. When this happens, it interrupts fuel delivery and damages your engine. This can prevent your Prius from starting.

– Security System Problems

You should check your security system if your car won’t start. These systems are protective systems put in place to prevent a malicious third party from gaining access to your car. A security system can cause your car not to start due to some defective components, such as an electrical short or a faulty starter.

– Flooded Engine Oil

An overfilled engine oil is another reason why your Prius won’t start. When the oil is overfilled, excess amounts can go into the combustion chamber or crankshaft and might prevent the vehicle from starting. While the oil capacity might vary amongst different generations of Prius, most of them use less than four quarts.

– Drained Key Fob Battery

If your Prius’s key has a push stop/start button, it’s possible that your car may not start owing to a dead key battery. The key fob is an important part of the car as it locks and unlocks the vehicle. However, a key fob with a dead battery will no longer unlock or lock the car, as your Prius will not be able to detect it. This will prevent the car from starting.

– Bad Camshaft/Faulty Sensor

If your camshaft is faulty, your Prius won’t start. The camshaft has a sensor which is known as a speed sensor, and if even the sensor is faulty, the car will not be able to start.

In most cases, the car eventually starts. However, you’ll probably drain the battery if you keep starting a car with a faulty sensor all the time.

– Loose Battery Terminals

Apart from a damaged fuse, a loose battery contact can prevent your vehicle from starting. This is a common problem and isn’t very obvious in a Prius, considering that the 12V battery engine isn’t used in this engine.
You should look out for corroded batteries as well as loose terminals. Either of these can prevent your dashboard lights from coming on. You should also look out for the quality of the cables attached to the terminals.

– Faulty Starter

A bad starter is another likely reason why your Prius has refused to start. This happens because the metal arms of the solenoid and the starter motor have worn out due to constant use and contamination.

The solenoid transfers electricity from the battery to the car’s starter, which causes the metal system to become less rigid and more brittle.So if your car refuses to start and the battery is okay, then the starter or solenoid is bad and needs replacing.

– Ignition Failure

Ignition problems are a major reason why your car won’t start. The ignition switch is the part responsible for sending power out to the starter when you turn it. If no ignition is created, the car will fail to start. A damaged spark plug is a cause of bad ignition problems, as well as a loose connection among the plugs.

– Defective Alternator

Another reason for the starting problems of a Prius is a defective or bad alternator. It’s an important part of your Prius as it provides the energy to charge the car. It also draws electricity from the battery and uses this to charge. While it can be very rare for modern alternators to break down, they can still become faulty and wear out based on use.

– Insufficient Battery Power

If your battery doesn’t have enough charge or has other battery problems, your car won’t be able to start. All good Prius batteries should last somewhere around 100,000 to 150,000 miles. Once it is less than that, you should promptly check the battery and its charge.

The average lifespan of Prius batteries is about 100,000 miles to150,000 miles, but if you take care of your battery, it could last even longer. If you are having any trouble with your battery, it’s recommended that you take it to an experienced mechanic for servicing.

– Removal of the Engine Coil

Another reason why your car won’t start is that the engine coil was removed from the car. These coils are essential for the smooth running of the car. The removal of these coils will alter the car’s performance and prevent it from starting.

How To Fix Your Toyota Prius That Won’t Start?

To fix your Toyota Prius that won’t start, you can unclog the filter, replace the engine coil, and reset the battery. You can also check the voltage of the alternator and use an OBD2 scanner for diagnosis. We recommend consulting a professional before carrying out any replacements or repairs.

– Change Engine Coil

You can replace your engine coil when your Toyota Prius refuses to start. Although it’s rare, they have been known to prevent cars from starting. It is important to fix or replace them once as soon as their symptoms appear. This is because your car won’t run on a faulty engine coil.

– Unblock Filter

To fix your vehicle, you might need to unclog the filter first. You cannot start a car with a blocked filter as it restricts the flow of fuel to the engine. If the filter is completely blocked, then you might have to replace it instead of fixing it.

Troubleshooting a Non Starting Toyota Prius


The engine might be damaged due to the blockage, so you should check with a professional mechanic before attempting any repairs.

– Restart Battery

Like most cars, the Toyota Prius uses a remote system that prevents it from starting if the remote battery is dead or drained. If this is the case, resetting the battery is another way to help your Prius start. However, you might need to check with a mechanic for more severe cases.

– Check the Voltage of the Alternator

One way to fix a Prius that won’t start is to check its alternator. You can check the alternator’s voltage by connecting it to a voltmeter when the car is off. Once you notice that there’s a decreased voltage, it’s an indicator that something might be wrong with your alternator.

– Use OBD2 Scanner for Diagnosis

Every Toyota Prius is equipped with on-board diagnostics 2 (OBD2), which can be used to troubleshoot the location of the malfunction. The OBD2 connector is usually located under the dashboard, and after connection, it will ask for some information about the engine. Enter these details correctly, as they will allow for proper diagnosis.

Checking Car Alternator Voltage

What Are the Common Causes and Fixes for a Car Hesitating to Start Similar to a Prius?

Car starting problems can be frustrating, especially when it comes to a Prius. Several factors can cause hesitation, such as a weak battery or faulty spark plugs. To fix this, check the battery’s connections, ensuring they are clean and tight. If that’s not the issue, consider replacing the spark plugs or seek professional assistance to diagnose and fix the problem swiftly.

Are Some of the Causes of a Rich Running Car Similar to a Prius Not Starting?

When it comes to car troubles, both a rich running car and a non-starting Prius can have similar causes. Common car running rich causes and fixes include a faulty oxygen sensor, dirty fuel injectors, or a clogged air filter. Similarly, a Prius not starting might be due to a weak hybrid battery or a faulty ignition switch.


You don’t need to panic anymore if your Toyota Prius won’t start.

Here’s a recap of the main points discussed in the article:

  • The reasons why your Prius won’t start include a faulty alternator, a defective spark plug, or a bad fuse.
  • Other reasons include battery issues, rat damage, or engine failure.
  • You can fix this problem by checking the voltage of the alternator and repairing the worn-out spark plug.
  • You can also use an OBD2 scanner for diagnosis as well as reset the battery.
  • Make sure you consult a professional mechanic for proper diagnosis before repairs.

With the information in this article, once you notice that your car refuses to start, you should be able to diagnose the problem and fix it immediately!

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