This article explains how to troubleshoot the E27 Motor Lock Protection error on an Aventon eBike.

Use this article if your bike:

• Shows an E27 error code
• Has reduced or no motor assistance
• The rear wheel does not rotate freely
• The bike stops assisting during riding

If you are unsure of your Aventon model, please confirm your model before continuing.

Stop troubleshooting immediately if anything looks unsafe, damaged, overheated, or if the rear wheel cannot rotate freely.

Before You Start

Please prepare the following:

• Order number
• Aventon model
• Photo or video of the E27 error code
• Photo of the display
• Photo of the rear wheel area
• Photo of visible motor or wheel damage, if relevant
• When the issue first appeared
• Whether the bike powers on
• Whether the display turns on
• Whether the motor engages
• Whether the issue happened after climbing, heavy load, transport, storage, water exposure, crash, impact, modification, or third-party repair
• Photos of visible damage

Safety Warnings

• Do not continue riding if the rear wheel does not rotate freely.
• Do not continue riding if the bike has visible damage, overheating, smoke, burning smell, or motor resistance.
• Do not open sealed electrical components.
• Do not work on wiring while the bike is powered on or charging.
• Stop and contact support if you are unsure.

What This Error Means

The E27 Motor Lock Protection error means the bike has detected a motor lock or excessive load condition.

This may happen if:

• Ambient temperature is too high
• The battery is damaged
• The eBike has been overloaded for an extended period of time
• The rear wheel cannot rotate freely

Possible Causes

Possible causes include:

• High ambient temperature
• Damaged battery
• Extended overload condition
• Obstruction preventing wheel rotation
• Tire interference
• Spoke interference
• Hub interference
• Brake interference
• Motor-related issue
• Controller-related issue

Troubleshooting Steps

Step 1 – Inspect the Rear Wheel for Obstructions

Turn the bike off before continuing.

Inspect the rear wheel and check whether it rotates freely.

Inspect the following areas for interference or obstruction:

• Tire
• Spokes
• Hub
• Brake area

Check for:

• Objects caught in the wheel
• Brake rubbing
• Physical obstruction
• Visible damage
• Resistance when rotating the wheel

Clear any visible obstruction if it is safe to do so.

Restart the bike and check whether the E27 error remains.

If yes – The E27 code still appears

Continue to Step 2.

If no – The error clears

The issue was likely caused by wheel interference or temporary overload.

Monitor the bike during future riding.

If the issue clears

Continue normal use and monitor the bike.

If the issue remains

Continue to Step 2.

Step 2 – Check Whether the Error Persists

After clearing any visible obstruction and restarting the bike, test whether the rear wheel rotates normally and whether the E27 error returns.

If yes – The E27 code still appears

The issue may involve the motor or controller system.

Please contact our support team with the photos/videos listed below so we can review the next step.

If no – The error no longer appears

The issue was likely caused by temporary wheel interference or overload.

Continue monitoring the bike during use.

Step 3 – Check for Signs of Overload or Heat

Check whether the issue happened:

• During hot weather
• After extended climbing
• During heavy load use
• After prolonged high motor demand

Allow the bike to cool down completely before testing again.

If yes – The issue happened during high load or high heat conditions

The issue may have been caused by motor protection activating due to excessive load or temperature.

Monitor the bike during future riding.

If no – The issue continues under normal riding conditions

Please contact support for further assessment.

If the issue remains

Please contact support.

Step 4 – Inspect for Battery or Visible Damage

Inspect the accessible battery and rear wheel area for:

• Visible damage
• Signs of impact
• Overheating
• Burning smell
• Swelling
• Water exposure

If yes – Visible damage is found

Stop using the bike immediately.

Do not continue riding or charging the bike.

Please contact our support team with photos/videos of the damaged area.

If no – No visible damage is found

Restart the bike and recheck the error.

If the issue remains

The issue may involve the motor or controller system.

Please contact support.

When To Contact Support

Please contact support if:

• The E27 error remains after completing these checks
• The rear wheel does not rotate freely
• The motor does not engage
• There is visible damage
• The bike overheats repeatedly
• The battery appears damaged
• The bike has been exposed to water, crash, impact, transport damage, modification, or third-party repair
• You are unsure how to safely complete a step

If the issue remains after these steps, please contact our support team and include the photos/videos listed below.

What To Send Support

Please send:

• Order number
• Aventon model
• Photo/video of the E27 error code
• Photo of the display
• Photo/video of the rear wheel area
• Photo of the battery area
• Photos of visible damage
• Confirmation of whether the bike powers on
• Confirmation of whether the display turns on
• Confirmation of whether the motor engages
• Confirmation of whether the rear wheel rotates freely
• Confirmation of whether the issue happened during hot weather, climbing, or heavy load riding
• Confirmation of whether the issue happened after water exposure, crash, impact, modification, or third-party repair
• Confirmation of the troubleshooting steps already completed

Important Safety Notes

• Do not continue riding if the E27 error remains.
• Do not ride the bike if there is visible damage, overheating, smoke, burning smell, or motor resistance.
• Do not open the motor, controller, battery, or sealed electrical components.
• Do not force connectors.
• Do not work on wiring while the bike is powered on or connected to the charger.
• Contact support if you are unsure.