This article explains how to troubleshoot the E41 Controller Error on an Aventon eBike.

Use this article if your bike:

• Shows an E41 error code
• Has display or controller communication issues
• Powers on intermittently
• Motor assistance does not operate normally

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

Stop troubleshooting immediately if anything looks unsafe, damaged, overheated, or smells burnt.

Before You Start

Please prepare the following:

• Order number
• Aventon model
• Photo or video of the E41 error code
• Photo of the display
• Photo of accessible display wiring and connectors
• When the issue first appeared
• Whether the bike powers on
• Whether the display turns on
• Whether the motor engages
• Whether the issue happened after charging, transport, storage, water exposure, crash, impact, modification, or third-party repair
• Photos of visible damage

Safety Warnings

• Do not continue riding if the bike has visible damage, overheating, smoke, or a burning smell.
• 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 E41 Controller Error means the controller has detected an internal warning or communication issue.

This may happen if:

• The controller is damaged
• The display cable or display harness is damaged
• There is a poor connection between the controller and display
• There is cable or connector damage

Possible Causes

Possible causes include:

• Controller internal warning or error
• Damaged controller
• Damaged display
• Damaged display wire harness
• Worn cable
• Broken connector
• Internal open circuit
• Visible cable or connector damage

Troubleshooting Steps

Step 1 – Inspect the Display and Display Cable Connection

Turn the bike off before continuing.

Disconnect, inspect, and clean the accessible:

• Display connection
• Display cable
• Display wire harness

Check for:

• Loose connections
• Bent pins
• Worn cables
• Broken connectors
• Dirt or contamination
• Visible cable damage

Reconnect everything securely and restart the bike.

If yes – Visible damage is found

Continue to the relevant section below:

• Display damage
• Display wire harness damage

If no – No visible damage is found

Fully reconnect the:

• Controller
• Display harness
• Display connection

Restart the bike and check whether the E41 error remains.

If the issue clears

The issue was likely caused by a loose or poor connection.

Monitor the bike during normal use.

If the issue remains

Continue to Step 2.

Step 2 – Check Whether the Error Persists After Reconnecting

After reconnecting all accessible cables and connectors, restart the bike and check whether the E41 error returns.

If yes – The E41 code still appears

The issue may involve the display, display wire harness, 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 a temporary communication or connection issue.

Continue monitoring the bike during use.

Visible Damage Troubleshooting

Step 3 – Display Damage Found

Inspect the display for:

• Cracked screen
• Physical damage
• Water exposure
• Loose wiring
• Broken mounting points

If yes

Do not continue riding the bike.

Please contact our support team with photos of the display and error code.

If the issue remains

The display harness or controller system may also be affected.

Please contact support.

Step 4 – Display Wire Harness Damage Found

Inspect the accessible display wire harness for:

• Cuts
• Worn insulation
• Pinched cables
• Loose connectors
• Bent pins
• Broken fittings

If yes

Do not continue riding the bike.

Please contact our support team with photos of the damaged harness and connectors.

If the issue remains

The display or controller system may also require further inspection.

Please contact support.

Step 5 – Check Whether Communication Problems Continue

Check whether:

• The display powers on intermittently
• The E41 error returns repeatedly
• The bike does not operate normally
• Motor assistance does not engage correctly

If yes

The issue may involve:

• The display system
• Display communication
• The display harness
• The controller system

Please contact our support team with:

• Video of the issue
• Video of the display during startup
• Photos of accessible connectors and wiring

If the issue remains

Please contact support.

Step 6 – Inspect for Visible Controller Damage

Inspect the accessible controller area for:

• Visible damage
• Burn marks
• Loose connectors
• Water exposure
• Damaged cables

If yes

Stop using the bike immediately.

Please contact our support team with photos of the controller area and visible damage.

If no

Restart the bike and check whether the E41 error returns.

If the issue remains

The controller system may require further inspection.

Please contact support.

When To Contact Support

Please contact support if:

• The E41 error remains after completing these checks
• The display does not turn on
• The motor does not engage
• There is visible cable or connector damage
• 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 E41 error code
• Photo of the display
• Photo of accessible display wiring and connectors, if safe
• Photo of the controller 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 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 E41 error remains.
• Do not ride the bike if there is visible damage, overheating, smoke, burning smell, or electrical issues.
• Do not open the controller, motor, 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.