"Brake Override Malfunction" Toyota Sienna - What's Wrong?

Toyota Sienna is a great minivan suitable for families. Economical and reliable, it seemed to be the car of your dreams. At least until you notice the Brake Override Malfunction message appear on the dashboard. Now, you're reluctant to drive your newly purchased car. Is this a serious issue or merely a nuisance?

Brake override malfunction message highlights

• Common reasons:brake switch dead, electronics issues
• How to fix:take it in for inspection
• Possible consequences:no serious consequences
• Priority level:Low
• Can you drive?Yes
• DIY repair:Impossible
• Repair price range:$150-$300

What is the Brake Override feature on your Toyota Sienna?

An important safety feature, the Brake Override system cuts off all engine power if you press the gas and brake pedals at the same time. This helps prevent accidents and might even save lives. The feature is also related to the function of your airbags.

Since safety should be every car's priority, a brake override malfunction can be a serious issue. Though you can drive your Toyota Sienna just fine for a while, we don't recommend it.

How to determine if your Toyota Sienna has a Brake Override Malfunction?

This issue has very few symptoms. However, they are all very easy to spot. You should first check your Toyota Sienna's dashboard. This is where the message will most likely appear. Keep in mind that older models might not display Brake Override Malfunction but might simply prompt the Check Engine Light.

Though you should be able to diagnose this issue based solely on this message, it never hurts to be thorough. Make sure you check for the symptoms we list in the later sections of this article.

Is the Brake Override Malfunction serious? Can you still drive your Toyota Sienna?

From a strictly technical standpoint, you can still drive your Toyota Sienna with the brake override malfunction. This feature isn't essential for the engine to run. However, we urge you not to drive your Toyota Sienna in this condition. Brakes are extremely important parts of every car. The ability to brake effectively practically defines a safe vehicle. A faulty braking system could lead to serious accidents.

Don't put this issue aside. In some cases, you might even be able to fix it yourself. Some causes are quite benign and easy to address. We'll discuss them in the later sections.

Will turning the brake override feature fix the malfunction on your Toyota Sienna?

Some Toyota models and years allow you to turn the brake override feature off. If you're unsure if yours is one of them, consult the factory manual.

But keep in mind that isn't a solution. Turning the feature off may fix the symptoms but it won't solve the cause. To ensure your Toyota Sienna is safe for the road, you should address the root of the issue.

5 common reasons that might be causing the brake override malfunction on your Toyota Sienna

Though you can drive your Toyota despite this issue, it's a serious safety hazard. Address the issue at your earliest convenience. To do so, you need to understand what can cause the problem in the first place. Some of the causes are easy to fix even without professional aid.

Here are the X common causes behind the brake override malfunction:

1) You have pressed the gas and brake pedals at once

Though the brake override feature is meant to turn off the engine when you press the gas and brake pedals at once, it's not perfect. Sometimes, the system will malfunction, and this message will appear on your dashboard.

How to fix it:

The solution to this cause is simple - try to avoid pressing both these pedals simultaneously. Unfortunately, you might have to try some of the fixes mentioned below once the issue occurs.

2) Damaged key fob

While key fobs are great for unlocking your Toyota Sienna from a distance, they can lead to complications sometimes. When you attempt to start it with a key fob, your car 'checks' the position of your feet. If they are on the pedals, it starts normally.

A weak or altered signal might distort this reading, possibly leading to this issue.

How to fix it:

The simplest solution is to change the battery in your key fob. Poor power source results in a weak signal and can cause the brake override to malfunction. If everything seems fine, check if your key fob isn't broken or cracked. If yes, it's time to replace it.

3) Your brake pressure sensor is damaged

As the name suggests, the brake pressure sensor gauges how much pressure you put on the brake pedal. If damaged, it will send wrong readings to the ECU (Electronic Control Unit). This can activate the brake override which in turn stops your engine. This can be dangerous if it happens at the wrong time.

Several additional symptoms may point to this problem. For instance, your brake light won't turn off even if you release the brake pedal. On the other hand, it might not light up when you press it as hard as you can. Both are signs of a malfunctioning brake pressure sensor.

How to fix it:

Unfortunately, you can't fix this issue yourself. The whole thing will likely need replacement. Thus, you'll have no other choice but to take your Toyota Sienna to a mechanic.

4) Your ABS module is broken

The ABS module buffers your Toyota Sienna's braking system. It can reduce sliding during braking. When it breaks, it can sometimes cause the brake override to malfunction. In this case, your ABS might completely take over your brakes which leads to several dangerous symptoms.

Your brake pedal might feel spongy if this is the case. Furthermore, your Sienna will take much longer to fully stop when you brake. This is incredibly dangerous and can lead to accidents. You can also identify this issue by checking the ABS light. If it's on even when it shouldn't be, something is clearly amiss.

How to fix it:

Sadly, this is another one of those issues you can't solve on your own. To avoid unnecessary risks, take your Toyota Sienna to an auto repair shop immediately.

5) Your airbag sensor is broken

The braking system communicates closely with the airbag. If the airbag sensor is faulty, your brake override features will stop working as well. This is intended to be a safety measure. Thus, your brake override malfunction might not be related to your brakes at all. Instead, your airbag sensor might be to blame.

One way to diagnose this problem is to check your dashboard. Your airbag warning lights might turn on if this is what caused the problem. On older models, this can be the Check Engine light instead.

How to fix it:

The issue can either be a broken airbag sensor or faulty wiring. In either case, you should seek the help of a professional to fix this issue.

Can you fix the brake override malfunction on your Toyota Sienna on your own? How?

Whether you can fix the issue yourself depends on what caused it in the first place. But in most cases, you'll need to visit a repair shop to remove the problem. Before you do, you can try the following two methods to try and fix it yourself. Though they're not guaranteed to work, they could save you some time and money if they do.

• Change the fuse in the engine fuse box

Sometimes, this issue can be caused by a blown fuse. To fix it, all you need to do is check the engine fuse box and replace it. The location of the fuse box varies from model to model. If you don't know where to look, check your manufacturer's manual.

• Reset your Toyota Sienna

Alternatively, you can disconnect the battery from your Toyota Sienna. To do so, first, remove the negative terminal and then move on to the positive one. Without a power source, the whole electrical system will run out of energy eventually. It usually takes up to 15 minutes for this to happen. You can turn your headlights on to speed up this process as they drain a lot of power.

After 15 minutes, you can reconnect the battery. All electrical components will reset. If the issue wasn't anything serious, the brake override malfunction should disappear from your dashboard. Otherwise, you might have to visit a mechanic.

Our final thoughts on the Toyota Sienna Brake Override malfunction message

When you get the brake override malfunction message on your Toyota Sienna, it might be dangerous for you to drive it. While the engine will run as normal, your brakes won't work as intended. Braking is a vital aspect of every safe vehicle. Without it, you risk accidents and possibly even death.

Many reasons can cause this malfunction message to appear. You can attempt to fix the problem yourself by checking the fuses and removing the battery for a bit. If the issue persists, other braking components in your car might be to blame. If so, you'll have to take your Toyota Sienna to an auto repair shop.