What Causes the Ender 3 (Pro/V2) Homing Failed Error? (How to Fix?)

With so many different components coming together and requiring the correct configuration for a successful 3D printing process, the chance of an error halting the printing process or the appearance of a silent problem adversely affecting the quality of your prints is pretty likely when you are first starting out.

On the other hand, once you set everything up, correctly configure them once, and achieve a successful print, you will most likely be able to enjoy the process of 3D printing without problems for a long time, most likely until you modify something, where the likelihood of a problem appearing increases.

Today, we have the Ender 3 homing failed error at hand, which is a critical error that can pop up during the automatic homing process of the Ender 3 and immediately stop the printer from operating without giving us a lot of insight into what is causing it, making it impossible to print until the problem is resolved.

So, what can cause your Ender 3 to display the homing failed error?

While the primary culprit behind the Ender 3 homing failed error is the endstops not functioning correctly due to complications such as incorrect wiring and faulty or mispositioned endstop switches (limit switches), issues with the firmware are also known to cause the problem.

Moving forward, we will analyze the potential causes behind the Ender 3 homing failed error in more detail, find out the most efficient ways to fix this problem, and take a closer look at the specific but common cases of homing failing only after installing a BLTouch, and only the Z-axis homing being unsuccessful.

What Causes the Ender 3 (Pro/V2) Homing Failed Error?

As the homing failed error in Ender 3 will immediately halt the printer due to its critical nature, it’s vital to locate the factor that’s causing this error as quickly as possible to be able to get your Ender 3 back in operating condition.

The most likely reason that will prompt your Ender 3 to display the homing failed error is a problem with the endstops, which are the components you can find on either side of each axis, responsible for letting the Ender 3 know the starting point of the axes.

When one or more endstops cease to function correctly, the Ender 3 won’t have access to the starting point of the problematic axes anymore, causing the homing process, which is what the 3D printer requires to determine the position of the printhead and the build plate at any given time, to fail.

Below, you can find the three common reasons that can prevent the endstops from functioning as intended, along with descriptions that explain how:

  • Wiring problems between the endstops and the control board – Endstop wiring issues are pretty common with the Ender 3 and are especially likely if you have assembled your Ender 3 for the first time or have operated in the area where the wires are located recently.
  • Defective endstop switches – Like any component, the endstop switches can eventually cease to function due to wear and tear or come out of the factory in a defective state.
  • Incorrect endstop switch positioning – While less common than the two issues we have mentioned above, it’s possible for the endstops to be positioned in a way where the printhead or the build plate runs out of space before reaching them, which usually happens due to something blocking the path.

On the other hand, in some cases, it’s also possible for the Ender 3 homing failed error to result from problems with the firmware, such as the firmware you have flashed being incompatible with your Ender 3, which is especially likely if you have flashed new firmware recently.

As the firmware is responsible for every single action of your Ender 3, it’s entirely natural for an issue with the firmware to present itself in many shapes and forms, even if you have managed to successfully install it on your 3D printer, including the homing failed error that you are facing.

How to Fix the Ender 3 (Pro/V2) Homing Failed Error?

As there are a few different potential culprits behind the Ender 3 homing failed error, it may be necessary to go through all the possible solutions for these culprits to ensure that you fix the problem, especially if you aren’t precisely sure about the actual cause.

Below is a list of solution suggestions for all the potential causes of the Ender 3 homing failed error, which we recommend carefully going through to fix the problem as quickly as possible:

  • Check and correct the wiring between the endstops and the control board. To be on the safe side, we highly recommend going through the assembly documentation once again, double-checking that all the wires between the endstops and the control board are intact and tightly connected to the correct spots.
  • Test the endstop switches manually, and replace them if necessary. The most straightforward way to test the switches without the wiring involved is to remove the endstop switch from the motherboard, connect a multimeter to it, and trigger the switch with your finger. If the switch is working correctly, the multimeter should react to the state change between the open and closed circuits.
  • Ensure that the printhead and the build plate can reach the endstops, and if not, correct the positioning of the endstops. The quickest way to do this is to closely observe the printhead and the build plate during the homing process and see whether they are hitting the endstops on all the axes as they should. In the case where there is no contact with the endstop switches, ensure that the endstop switches are at the correct positions and nothing is blocking their path.
  • Install an updated version of the Marlin firmware from the official website. Marlin firmware is one of the most reliable and feature-packed options for an Ender 3, and flashing an up-to-date version of Marlin will ensure that you won’t face firmware-related problems.

As always, we recommend running a test print after applying each solution, which will save you from wasting your time on more solutions when the problem could already be resolved and allow you to pinpoint the cause, which you can utilize to take preventative measures.

Ender 3 (Pro/V2) Homing Failed After Installing BLTouch – What to Do?

While the Ender 3 homing failed error can pop out of nowhere, it could also be your printer’s reaction to a modification you have performed recently, such as installing a BLTouch automatic bed leveling sensor.

Assuming that you have wired the BLTouch correctly, the most likely culprit behind the Ender 3 homing failed error popping up right after installing a BLTouch auto bed leveling sensor is the usage of firmware incompatible with the BLTouch or not configured to work with it.

As a result, our primary recommendation would be to download the latest version of Marlin firmware, modify the necessary files to make the firmware compatible with BLTouch (while Marlin offers full support for BLTouch, it’s not active by default), and flash the modified firmware to your Ender 3.

Finally, while rare, in some cases, it’s also possible for some of the wires to get unplugged by accident during the BLTouch installation process, which makes it a good idea to go through all the wiring and ensure that everything is in order.

Ender 3 (Pro/V2) Z-Axis Not Homing – What to Do?

In some cases, while the X and Y axes of your Ender 3 will home without any issues, the Z-axis will fail to home, which is a problem that deserves a separate mention due to it being a more specific case compared to the homing failed error.

In the case of only the Z-axis of your Ender 3 failing to home, we can immediately tell that the Z-axis endstop is the culprit, meaning that either there are problems with its wiring (especially likely if you have been working on your Ender 3 lately) or the endstop switch is not functional anymore.

To resolve the problem, we would highly recommend going through the wiring between the Z-axis endstop and the control board as the first step, and if that does not help, manually testing the endstop switch with a multimeter and replacing it if necessary.

Finally, while a rare occasion, it’s worth mentioning that a faulty mainboard can also be the culprit behind the issue of your Ender 3’s Z-axis not moving, which is something to keep in mind if you are sure that there are no issues with the endstop itself.

Wrapping Up

The Ender 3 homing failed error is one of the more problematic issues you can face due to it entirely stopping the 3D printer from operating and due to there being a few distinct and unrelated culprits that can cause the error that make the fixing process more challenging and time-consuming.

To quickly recap, endstop-related issues, such as incorrect wiring, faulty endstop switches, or the endstops being mispositioned, are the main factors behind the Ender 3 homing failed error, followed by firmware-related problems, such as the usage of incompatible firmware.

Fortunately, there isn’t a whole lot of technical complexity involved in solving this problem, as going through the fixes for both endstop-related issues and the firmware-related issues are relatively straightforward and can even be considered routine.

Happy printing!