ER01 - Stopped temp sensor

This error message refers to a problem with the sensor that measures the nozzle temperature. The (PT100) sensor measures incorrect values and, due to safety reasons, the printer will prevent the nozzle from heating up.

The most likely cause for these errors is a connection problem. This can be a loose connector or damage to one of the components.

Caution: When troubleshooting this error, turn off the printer and disconnect the power cable.

Check the print head

First, take a look at the back of the print head. The PT100 is the thinner of the two wires that come out of the back of the heater block.

Check if the sensor is fully inserted into the heater block and if there are no signs of damage to the wire. If the wire is disconnected, reinsert it into the heater block and tighten the screw to secure it. If the wire looks damaged, it must be replaced.


Tip: As seen from the back of the print head - Left is the heater, right is the sensor.

Check the mainboard

The sensor may not be connected correctly to the mainboard anymore. To check this, place the printer on its side and remove the mainboard cover.

Remove the mainboard cover

  1. Gently place the printer on its left side.
  2. Manually raise the build plate. You will need access to the bolts in the bottom panel that secure the bottom cover.
  3. From the inside of the printer, loosen the two bolts of the bottom cover using the 2 mm hex key or screwdriver. While doing so, hold the lock nuts at the bottom side of the printer with pliers or a (socket) wrench.
  4. Remove the bottom cover from the mainboard and place it aside.







Check the connections

With the mainboard now exposed, look for the connector marked 'TEMP1'. The temperature sensor of the print head must be connected here. Reconnect the cable if necessary.

Tip: This is difficult, but possible without removing the mainboard. If you are in doubt whether the cable is connected correctly, you can loosen the mainboard from the bottom panel.

Note: The temperature sensor for the Ultimaker 2+ and Ultimaker 2 Extended+ is more robust than the sensor of the non-plus series. For an Ultimaker 2, Ultimaker 2 Extended, or Ultimaker 2 Go, make sure that the thin red and white wires are all still securely inserted into the connector. If one of the wires is loose, the PT100 should be replaced.

the_PT100_sensor_should_be_connected_to_TEMP1.jpg Make_Sure_wires_properly_inserted.png

Connect the sensor to TEMP1


The non-plus PT100 sensor


Turn on the printer and check if the error is resolved. If it still appears, the error is likely caused by a damaged component. Try swapping the connections, as described below, to determine if the sensor or the mainboard is defective.

Swap connections

If the error is not caused by a loose connection, swap the sensors of the print head and build plate to determine the root cause of the problem.

Note: Turn off the printer before proceeding.

  1. Disconnect the sensors from TEMP1 and TEMP3 on the mainboard.
  2. Connect the heated bed sensor to TEMP1.
  3. Connect the print head sensor to TEMP3.
  4. Turn on the printer again.


If the error appears straight away, check the table below. If this is not the case, first heat up the build plate and nozzle via the Maintenance - Advanced menu. Which error appears on the display now will indicate the cause of the problem:

Error stopped temp sensor (ER01) If the same error (ER01) appears when the connections are swapped, the issue is in the mainboard. If the connector is broken or if there is internal damage on the mainboard, the mainboard must be replaced.
Error stopped temp sensor bed (ER02) If a different error (ER02) appears when the connections are swapped, the problem has moved along with the sensor. This indicates that the print head sensor cable is broken. There might be internal damage and it must be replaced.

Need further support?

If you require further assistance with troubleshooting, or when you need replacement parts to resolve the issue, contact support or your local reseller.

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