Can You Reset the ECU by Pulling Fuse? My Explanation

Resetting the ECU is sometimes super important to get your car back on the road. Sometimes, you will want to get it out of the limp mode, at other times, you will want to get some lost functions back. Anyway, the most well-known method to reset the ECU is to disconnect the battery. But we all know there are some risks.

Can you reset the ECU just by pulling the fuse that powers this unit? Yes, you can. The fuse is usually located in the main fuse box under the hood. You will need to look at the fuse map that's on the lid of the box or find the fuse diagram for your vehicle and locate it. Then you just pull out the ECU fuse for 2-5 minutes and insert it back. Now, your ECU is refreshed and ready to go.

Will it solve all your problems with the car? Probably not. But will it help you resolve some software issues? Probably yes.

Resetting the ECU by pulling the fuse - short manual

So, if you want to keep all the settings in your car untouched (such as radio, clock, seat memory, etc.), you should opt for the fuse method to reset the ECU. In this case, you will keep the power on the Body Control Module and the majority of settings will be safe from deleting.

To accomplish this, you will need to do the following:

• open the hood and locate the main fuse box;
• first of all, take the lid out of the fuse box and check the fuse map on it;
• find the fuse that powers the ECU in your car - it will differ from one model to another;
• locate the fuse puller that's usually attached to the lid of the box;
• use the fuse pullet to carefully pull the ECU fuse out of its place;
• wait for several minutes till the ECU properly resets without power;
• insert the ECU fuse back in its place;
• start the car and check if everything is working properly.

When you are pulling out the fuse, you are leaving the ECU with zero power supply. That's why it clears all the current memory and completely resets its functions to the manufacturer's settings. While it isn't the magical method for curing any car problem, it can sometimes help with clearing the error codes or messages or taking your car out of the limp mode.

Things are a little more complicated if the ECU fuse is integrated into the multi-fuse bar. You will need to unscrew several more nuts, in this case.

Are there any risks in resetting the ECU through the fuse?

Although this process seems pretty straightforward and much less complicated than the battery-disconnection method, you should be careful.

One of the possible issues is that if you keep doing this often, you risk damaging the fuse box. In this case, you may eventually have to replace the main fuse box and this is not as cheap as it may seem at first.

Also, there is a risk of letting some water drop into the fuse box and do bad business there. For example, if you open the fuse box when it rains or snows, there is a huge risk that your box will eventually develop some corrosion, and nasty things will start happening with the car.

One more concern is that you can drop the fuse and will have to get a new one because your old one will be wet or damaged. If you don't have a spare fuse, you will not be able to drive your car till you get one.

So, it isn't as easy and risk-free as it may seem at first. And I strongly recommend staying away from the fuse box if you don't know what to do.

How should you prepare for the task?

In order to do everything right, you should prepare yourself a little for resetting the ECU in your vehicle. For this, it's important to complete these simple tasks:

• get a spare fuse of the proper amperage;
• find a fuse diagram for your car in the manual or online;
• make sure you are planning to do the job on the dry and sunny days;
• find a place where you have proper access to the fuse box;
• plan some time for this procedure, so that you don't hurry up;
• get a fuse puller just in case your OEM puller isn't there for some reason.

These steps will help you prepare for resetting the ECU by pulling out the fuse and will obviously reduce the risks associated with this task.

Of course, if you have a friend who knows something about car electrical systems, I strongly recommend you grab a couple of cans of beer and ask your friend for help.

What are two other methods of resetting the ECU?

There are two methods that may help you reset the ECU without touching the fuse box. They also have their risk and aren't ideal for everyone but one of them may be actually more recommended for car owners who don't have any experience with car repair.

Here are these methods:

1) Disconnect the clamp on the ECU

If the ECU is easily accessible in your car, you may disconnect it and reset it this way. In most cases, you will need to unscrew several bolts or nuts and just take off the connection. Wait for several minutes and connect the ECU back.

This method won't work for vehicles that have an intricate location of the ECU (like under the front panel or somewhere in the engine bay where you can't physically reach it.

But it will perfectly work for the majority of cars. Also, this is the method that the majority of mechanics use in car dealership shops or independent shops.

Also, I wouldn't recommend playing with this clamp too often. It has the same risks as pulling the fuse. You may damage the connections, let some water come inside, etc.

2) Disconnect the battery

This is the most popular and common method of resetting the ECU and also other control modules. While it's not the most beneficial way to deal with car problems, it can potentially help you solve the issues, and not only with the ECU, for a couple of minutes and for zero dollars.

When you are doing this, be sure to follow this short manual:

• turn off everything in your car and don't keep the key in the ignition;
• open the hood and locate the battery;
• find the negative terminal (usually, the battery has the minus on it near the terminal);
• unscrew the bolt on the cable clamp and take it off;
• then repeat this with the positive terminal;
• make sure the cables don't touch the battery terminals by chance;
• press the horn or turn on the lights to use all the remaining power;
• wait for 5-7 minutes to let the control modules completely reset;
• connect the positive terminal first;
• them carefully connect the negative terminal;
• turn on the car and see if the problems are solved.

While I gave this short manual about a hundred times on my blog, I will still repeat it in any article that has something to do with disconnecting the battery. If you take off the cable from the positive terminal first, there is a pretty high risk of frying something important in your car.

Also, make sure that the terminals are clean and that you tighten the bolts on each cable clamp properly. Otherwise, the car may suddenly lose power and fail to start one day.

What should you choose, in my opinion?

If you need to reset the ECU just once during a very long time period, you may use the fuse-pull method or the ECU-disconnection method. They are pretty driver-friendly and pose fewer risks to your car if you know how to do things.

If you somehow need to reset the ECU more often than once a month, I strongly recommend against digging in the fuse box or having something to do with the ECU clamp. Otherwise, you may need expensive repairs, in the end. In this case, you better choose the battery-disconnection method.

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