Why Does My EFI Fuse Keep Blowing?

Your EFI fuse could keep blowing due to several reasons. It could be a short circuit related to a faulty O2 sensor, the ECM, or a circuit overload due to some other component drawing a huge amount of current. Regardless, it is an issue that needs a fix at a moment’s notice.

The electronic fuel injection fuse is a vital component in a car’s engine system because it electrically controls the injection of fuel into the engine’s manifold. It also controls the ECU which acts as the main computer of the engine. If your EFI fuse keeps blowing, this article demonstrates how you can identify the issue and fix it.

Why Does My EFI Fuse Keep Blowing?

Your EFI fuse might be blowing due to some specific reasons. The reason could be something as simple as a short circuit to a faulty O2 sensor. If your EFI fuse keeps blowing and you cannot pinpoint the exact reason by yourself, here are some of the possible ones worth looking into.

Old Fuel Pump

An old fuel pump can be a liability to the system with the age. As they age, they draw more current from the system which may cause the fuse to pop as a safety measure. This issue is often seen and is not much difficult to deal with

You can troubleshoot by running a jumper wire temporarily back to the fuel pump. The better step is to disconnect the fuel pump wiring closest to the fuse box. Then you have to check it for unexpected ground. Do this with all the wires until you find the one responsible for blowing the fuse.

Faulty O2 Sensor

O2 sensors are delicate yet a critical component of the car’s exhaust system. they can get burned, cracked, or shorted pretty easily. The EFI fuse supplies the EFI main relay and powers the fuel pump, ignition switch, and starter relay. It also powers the ECM.

Therefore, if a sensor associated with the ECM gets shorted, it will blow the EFI fuse. We know that an O2 sensor is related to the ECM. If this sensor is shorted, the ECM will try to read them and blow the fuse as a result. The fix here is to check the wiring and disconnect them. That way the car should work just fine.

Short Circuit

Typically, a blown fuel indicates a short-to-ground fault. It is a situation where the electricity finds a connection to the ground before the load itself. As the circuit has no load, the wire carries a high current. 

Often when the brakes are applied, the EFI fuse blows as a result of a short in a single ECM connector. In that case, disconnect the brake switch and put in a new EFI fuse to see if it helps.

Too Much Current Drawn By Some Other Component

There may be some other component in your EFI system that is taking too much current. The EFI fuse detects this and as a safety measure, blows itself to protect that particular component.

What Is the Function of EFI Fuse?

The function of an EFI fuse is to control the engine ECU. It does so by supplying the EFI Main relay. This enables the system to power the fuel pump, ignition switch, and starter relay. Other than that, it powers the ECM computer which acts as the main computer for optimizing a vehicle’s engine performance.

How Do You Fix a Fuse That Keeps Blowing?

Fixing a fuse that keeps blowing is a pretty straightforward method and simple. All you have to do is to unscrew the old or blown fuse and replace it with a new one.

Another option for you to try out is to flip the tripped circuit from the center position to the off position. Then you have to flip it back to the on position. Lastly, turn the main power back on to see if it resolves the issue.

Frequently Asked Questions

What would cause a fuse to keep blowing?

A common reason why a fuse might keep blowing is when the circuit is overloaded. In other words, when too many appliances are connected to the circuit and draw power at once, the fuse might blow. This is true for all systems.

What is an EFI in a car?

The EFI or Electronic Fuel Injection in a car eliminates the need for a carburetor that mixes air and fuel conventionally. Instead, the EFI injects the fuel more effectively and directly into the engine’s cylinder by using electronic controls.

Conclusion

EFI fuse is a vital component in a car’s engine system that controls the engine’s main computer, ECU. If your fuse keeps blowing, it is not a grave issue to worry about. Do not panic and see whether it is a simple short circuit related to the ECU or a circuit overload. Try some basic troubleshooting and if it fails, replace the fuse with the help of a mechanic.