Prusa error 13313 (I2C Send Timeout) appears on the MK4 and its equivalents are #31313 on the CORE One, #35313 on the CORE One L, #26313 on the MK4S, #27313 on the MK3.9S, #21313 on the MK3.9, #28313 on the MK3.5S, #23313 on the MK3.5, and #12313 on the MINI. The firmware started an I2C write operation but the peripheral did not respond within the allowed time window, causing the transmission to time out.

What the Error Means

An I2C send timeout differs from a send failure in that the bus transfer was initiated but the target device stopped responding mid-transaction, or did not acknowledge at all within the timeout period. This can indicate that a peripheral device on the I2C bus — such as the accelerometer, LCD driver, or an expansion board — lost power or became unresponsive temporarily. In most cases this is a one-time transient event. Persistent timeouts suggest a loose connection to an I2C peripheral or, in rare cases, a hardware issue with the Buddy board’s I2C controller.

Step-by-Step Fix

1. Restart the printer. The error is not expected to recur after a clean boot cycle in the vast majority of cases.
2. Power cycle with a 30-second wait. If a simple restart does not clear the error, shut the printer down completely, unplug from the wall outlet, and wait 30 seconds before reconnecting and powering on.
3. Check I2C-connected peripheral connectors. With the printer off, inspect the connectors for the LCD display (ribbon cable), the accelerometer board (a small board typically mounted near the printhead), and the Wi-Fi module if applicable. Confirm each connector is fully seated.
4. Update firmware to the latest release. Firmware updates frequently include I2C timeout threshold adjustments. Download from prusa3d.com/drivers and install via USB.
5. Contact Prusa Support if the timeout is reproducible. If the error appears at the same point during every startup or print, note what sequence triggers it and share that information with support.

Parts Required

• No replacement parts are typically required for this fix — basic tools only

If the error persists after updating firmware, contact Prusa Support at help.prusa3d.com with details on when the timeout occurs.

Frequently asked questions

What does Prusa 13313 mean?

Prusa error 13313 (I2C Send Timeout) appears on the MK4 and its equivalents are #31313 on the CORE One, #35313 on the CORE One L, #26313 on the MK4S, #27313 on the MK3.9S, #21313 on the MK3.9, #28313 on the MK3.5S, #23313 on the MK3.5, and #12313 on the MINI. The firmware started an I2C write operation but the peripheral did not respond within the allowed time window, causing the transmission to time out.

How do I fix Prusa 13313?

Prusa error 13313 means the Buddy board timed out during an I2C send operation. Learn how to restart, update firmware, and check peripheral connectors to clear this fault.