PID Autotune Failed! Temperature Too High – What Causes It?

It’s undeniable that 3D printing isn’t a technology that is entirely error-free right now, meaning that every 3D printing enthusiast should be ready to deal with errors and problems that may appear along the way.

3D printers being customizable does not help this situation either. As it’s possible to replace and modify most parts of a 3D printer, many errors show up due to the misconfiguration of the new addition or incompatibility between the part and the printer.

Today’s topic will be one such problem, often caused after replacing a part in your 3D printer with an incompatible one, and also a very frustrating one as it’s usually caused by overlooking a simple factor.

So, what causes the “PID autotune failed! Temperature too high” issue, and how can you fix it?

In almost all cases, the “PID autotune failed! Temperature too high” error is due to using an incorrect heater cartridge in your 3D printer.

For instance, if a 24V adapter is powering your 3D printer, and you use a 12V heater cartridge, you will most likely encounter this error as a result of it.

As you can see, such a simple mistake can cause a very frustrating error that may take hours to fix, especially if you aren’t sure where to start looking.

Moving on, we will be diving deeper into the causes behind this error, the technical explanation for it, and the things you can do to fix this error and go back to 3D printing.

What Causes the “PID Autotune Failed! Temperature Too High” Error?

The “PID autotune failed! Temperature too high” error is a disappointing one without a doubt, especially considering that it mostly happens right after you add a new upgrade to your 3D printer, taking all the excitement away.

If you have encountered this error, you most likely have a made a change to the hotend of your 3D printer in some way, such as switching to a dual extruder system, changing the hotend, or changing the heating block of the hotend.

As you can see, in all of these cases, the heater block of your 3D printer is different than the one you originally had, which is essentially the root of the problem.

The “PID autotune failed! temperature too high” error is due to the heater block’s voltage requirement being lower than the voltage the power supply of your 3D printer provides.

When the voltage output of the power supply is greater than the heater block’s input requirement, the power that flows into the heater block becomes more than it can handle, causing the temperature to rise uncontrollably.

Let’s take a quick look at an example that will make it easier to understand.

Imagine that you have an Ender 3, which comes with a 24V power supply. Similarly, the heating blocks of the components such as the hotend and the hotbed also run on 24V.

If you mistakenly replace the current heating block with a 12V one, you will be overvolting the heater block (as the power supply is still sending 24V) and giving it four times more power than it can handle.

As a result, the temperature of the heater block spikes, causing the firmware to prompt the error message, stating that the temperature is too high.

Aside from the error, overvolting the heater block can cause dangerous issues, such as the heater block melting due to its electrical components not being able to handle the overvolting.

We highly recommend double-checking the power supply and the heater block to avoid such issues and being extra careful when dealing with electricity and electrical components in general.

How to Fix the “PID Autotune Failed! Temperature Too High” Error?

After identifying what causes the “PID autotune failed! Temperature too high”, fixing is a straightforward process that will require you to go over all the components you have changed.

Here are the steps we recommend taking for fixing the error.

  1. Start by looking at the power supply of your 3D printer, and make a note of its output.
  2. Look at the input requirements of all the components you have changed, and compare them to the output of your power supply.
  3. Remove the components that have a mismatch with your power supply, and reinstall the original ones.
  4. Start the PID autotune process again, and observe the results.

More often than not, installing the original components back into the printer will solve the issue as any mismatch between the components and the power supply will be removed.

What Is the “PID Autotune Failed! Timeout” Error?

While not as common, the “PID autotune failed! timeout” is another error you can get during the PID autotuning process with Marlin firmware.

This error happens as a result of either the hotbed or the hotend not reaching the desired temperature in the amount of time allocated by the firmware, which is why it’s called a timeout.

There are mixed opinions about this error in the community, with some users claiming that their hotend or hotbed is easily able to go up to the required temperatures during regular use, but the PID autotune process fails due to timeout, possibly because it’s incorrectly configured with unreasonable timeframes.

While this error could be a sign that something is wrong with your hotbed or hotend, in the case where you don’t have issues with them reaching the desired temperatures during print, here is the recommended fix to the error.

  1. If you’re facing the issue while autotuning your hotbed, start by insulating the bed as much as possible.
  2. Preheat the hotbed or the hotend slightly below the levels you are targeting for the PID autotuning process.
  3. Start the PID autotuning process quickly after the preheating process is over.

While this is more of a band-aid fix, it’s completely fine to use it if you aren’t having temperature-related issues with your hotend or hotbed during regular usage or with different firmware.

Wrapping Up

Even though the “PID autotune failed! Temperature error” text can be a frustrating one to see on your screen, its solution is quite simple once you know the cause.

To quickly recap, the most likely culprit behind this error is the voltage requirement of your heater block being lower than what the power supply provides, which can only happen if you have replaced a heater block or a part that has a heater block in it.

It’s an undeniable fact that customization is a significant part of the 3D printing world due to the many advantages it brings to your 3D printer, but being careful about the customizations you add is also a vital part of the process to avoid worse issues down the road.