Mistake of the collision sensor in the vacuum cleaner Xiaomi: causes and 7 ways to eliminate

Your Xiaomi robot vacuum cleaner suddenly stopped and signals a collision sensor error? Don't rush it to the service center. 80% of the time, the problem is solved by yourself in 10 to 30 minutes - without a soldering iron and special tools. This error (code 10, 11 or voice message like "obstacle detected") occurs due to a malfunction of bumper sensors, which are responsible for detecting obstacles and protecting the body from impacts.

We analyzed user reports and service manuals for Mi Robot Vacuum-Mop 2 Pro, Viomi models. V3, Dreame D9 And we've got all the tools we need to do to get the job done, from simple methods (reboot, clean up) to complex methods (disassembly, sensor replacement), and an error encoding table and answers to frequent questions. If you have doubts after reading this, there is an interactive survey at the end that will help narrow down the range of possible causes.

What does the collision sensor error mean?

A collision sensor (aka bumper sensor or bumper sensor) is a mechanical device located under the front panel of a vacuum cleaner.

• 🔘 Spring mechanism – triggered by physical contact with an obstacle.
• 📶 Infrared sensor – captures the push of the bumper and sends a signal to the board.
• 🔌 Microswitch - closes/unlocks contact on impact.

When the vacuum cleaner hits an obstacle, the bumper shifts 1-2 mm, the sensor detects this and tells you to stop or change the trajectory. The error occurs if the sensor has detected a false alarm (for example, due to dirt) or stopped responding to real collisions. Depending on the model, the error code may differ:

If your model is not listed in the table, check the error code in the Mi Home instruction or application. For example, in Dreame, errors can be duplicated in the Cleanup Log section. → Reporting errors.

⚠️ Attention: If the vacuum cleaner produces a collision sensor error without physical contact with obstacles (for example, standing still and beeping), the problem is most likely to be contamination of the mechanism or damage to the plume.

Causes of error: from dust to fee breakdown

We have collected all possible causes, ranked by frequency of occurrence (from the most common to the rare):

• 🧹 Bumper or sensor contamination – dust, hair, debris block the moving parts of the mechanism (occurs in 60% of cases).
• 🔋 Firmware failure – after software updates, the sensor may not work correctly (relevant for models with Wi-Fi).
• 🔌 Contact oxidation – moisture or condensate causes corrosion on sensor connectors.
• 🛠️ Mechanical damage – crack in bumper or broken spring after falling.
• 🔄 Incorrect calibration – after battery replacement or resetting settings.
• 💻 Breakdown of the motherboard - rare, but occurs with voltage surges.

To determine the cause accurately, perform a diagnosis of the symptoms:

If the vacuum cleaner doesn't respond to obstacles at all, the problem is more likely to be a plume break or a micro-switch malfunction, and if it does, on the contrary, stops too often, it's dirt or calibration failure.

Method 1: Reset and reset settings

Start with the simplest, software reboot, which helps 30% of the time, especially if the bug is triggered by a software update or power failure.

Instructions:

1. Turn off the vacuum cleaner with a long press on the power button (5-7 seconds).
2. Disconnect the battery for 1-2 minutes (if the model is collapsible).
3. Connect the power and turn on the device.

If the error persists, reset to factory settings:

• For models with buttons: press and hold home + Power 10 seconds.
• For smart vacuum cleaners: in the Mi Home app, go to Device Settings → Reset.

⚠️ Warning: After the reset, you will have to reconfigure your Wi-Fi, room maps and cleaning schedule. If the vacuum cleaner is tied to your Xiaomi account, log in again in the app.

Method 2: Cleaning the bumper and sensors

The most common cause of false positives is a buildup of dirt in the bumper mechanism, where dust, hair and debris block the moving parts, and the sensor constantly thinks the vacuum cleaner has hit an obstacle.

How to clean:

1. Turn the vacuum cleaner over and remove the front panel (usually mounted on latches or 2-4 screws).
2. Remove debris from under the bumper using a toothpick or compressed air.
3. Wipe the sensor contacts with an alcohol tampon (do not use wet wipes!).
4. Check the springs – they should freely compress and return to the original position.

For Viomi models V3 dreame D9 Pay special attention to infrared sensors (the little black windows on the sides of the bumper) and clean them with a soft brush to avoid scratching the lenses.

After cleaning, turn on the vacuum cleaner and check for the reaction to obstacles. If the error persists, proceed to the next method.

Method 3: Calibration of sensors (for models with LDS)

Xiaomi vacuum cleaners with laser scanner (LDS, For example, Mi Robot Vacuum-Mop 2 Pro requires periodic calibration of the sensors, and if the collision sensor is lost, it can be recalibrated through the service menu.

Step-by-step:

1. Place the vacuum cleaner on a flat surface (such as a table) at a distance of 0.5 m from the walls.
2. Press the buttons Home + Spot Cleaning for 5 seconds until you hear a beep.
3. Let go of the buttons, the vacuum cleaner will start spinning and squeaking. Don't touch it!
4. Wait for completion (about 1-2 minutes) and the vacuum cleaner will say "Calibration complete" or will emit a long signal.

If the calibration didn’t help, try updating the firmware through the Mi Home app:

• Open the app and select your vacuum cleaner.
• Go to Settings. → Update of the PO.
• If a new version is available, install it.

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Calibration of sensors should be carried out after any disassembly of the vacuum cleaner, replacement of the battery or falling from a height.

Method 4: Checking the plume and contacts

If cleaning and calibration didn't work, the problem could be that the plume connecting the sensor to the motherboard is damaged, which is true for vacuum cleaners that often drop or move horizontally.

How to check:

1. Remove the top cover of the vacuum cleaner (a screwdriver will be required). T5 or T6).
2. Find the plume running from bumper to board (usually black or gray).
3. Unplug and reconnect the connector. Make sure the contacts are not bent.
4. Check the plume for tears or scuffs.

If the plume is damaged, it can be replaced by yourself (cost – 300-800). ₽ depending on the model:

• 🛒 Buy the original plume (the article is usually listed on the cable itself).
• 🔧 Carefully solder the old and solder the new (or use connectors if the train is removable).
• 🔄 After replacement, perform sensor calibration.

⚠️ Warning: If you're not sure about your soldering skills, you'd better contact the service.Incorrect replacement of the plume can damage the motherboard.

Method 5: Replace the collision sensor

If all the previous methods didn't work, the sensor itself probably failed, and in that case, it would need a replacement. The cost of a new sensor is 500 to 1500. ₽ (model-wise).

How to replace the sensor:

1. Buy the original sensor (for Xiaomi Mi Robot will fit the article) MDY06-EM, for Viomi V3 — VIOMI-BUMPER-03).
2. Remove the front panel and bumper (see video instructions for your model).
3. Disconnect the old sensor from the board and install a new one.
4. Collect the vacuum cleaner and perform calibration.

The Dreame models are more complicated, because the sensor is integrated into the bumper, so you have to change the entire front panel. The average cost of working in the service is 1000-1500. ₽.

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Before you buy a sensor, check its compatibility with your model vacuum cleaner. 1S Not suitable for Viomi V2, even if they look similar in appearance.

When to contact the service

Self-repairing is not always possible. Contact Xiaomi Service Center if:

• 🔧 You dismantled the vacuum cleaner, but found no visible damage.
• 💥 The error occurred after falling from a height or impact.
• 🔥 On the board, traces of burns or bloated capacitors are visible.
• 🔄 The vacuum cleaner does not turn on at all (even after discharge).

Average cost of diagnosis in official services – 500 ₽, Repair of the collision sensor costs 1500-3000 ₽ (If the vacuum cleaner is guaranteed, the repair will be free of charge.

Before the service visit:

• Keep a check or a warranty card (if any).
• Reset the vacuum cleaner to factory settings (to delete personal data).
• Pack the device in the original box or wrap it in bubble wrap.

FAQ: Frequent questions about collision sensor error