This article explains how to troubleshoot the E45 Speed Sensor Error on an Aventon eBike.

Use this article if your bike:

• Shows an E45 error code
• Has incorrect speed readings
• Loses speed display information
• Has inconsistent motor assistance related to speed detection

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 E45 error code
• Photo of the display
• Photo of the motor and rear wheel area
• Photo of accessible motor harness connectors
• Screenshot of the Aventon App firmware version, if available
• When the issue first appeared
• Whether the bike powers on
• Whether the display turns on
• Whether the motor engages
• Whether the speed display works correctly
• Whether the issue happened after charging, transport, storage, water exposure, crash, impact, modification, firmware update, or third-party repair
• Photos of visible damage

Safety Warnings

• Do not continue riding if the bike behaves unpredictably or loses motor assistance unexpectedly.
• Do not continue riding if there is visible motor 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 E45 Speed Sensor Error means the bike is not receiving correct speed sensor information.

This may happen if:

• The speed sensor is damaged
• The speed measuring magnet is damaged
• The motor harness or controller connection is damaged
• The hub motor is damaged

Possible Causes

Possible causes include:

• Damaged speed sensor
• Damaged speed measuring magnet
• Damaged motor harness
• Damaged controller
• Damaged hub motor
• Worn cable
• Broken connector
• Internal open circuit
• Visible cable or connector damage

Troubleshooting Steps

Step 1 – Inspect and Reconnect the Motor Harness Connections

Turn the bike off before continuing.

Disconnect, inspect, clean, and reconnect the accessible:

• Motor harness connections
• Controller connections

Inspect the hub motor area for visible damage.

Update the firmware to the latest version using the Aventon App if available.

Restart the bike and check whether the E45 error remains.

If yes – Visible damage is found

Continue to the relevant section below:

• Controller damage
• Motor harness damage
• Hub motor damage

If no – No visible damage is found

Fully reconnect the controller and motor harness.

Restart the bike and check whether the E45 error remains.

If the issue clears

The issue was likely caused by a loose connection or temporary communication issue.

Monitor the bike during normal use.

If the issue remains

Continue to Step 2.

Step 2 – Check Whether the Error Persists

After reconnecting the system and restarting the bike, check whether:

• The speed display works correctly
• The motor engages normally
• The E45 error returns

If yes – The E45 error still appears

The issue may involve the motor or speed sensing 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 loose connection or temporary interruption.

Continue monitoring the bike during use.

Visible Damage Troubleshooting

Step 3 – Controller Damage Found

Inspect the accessible controller area for:

• Cracks
• Burning smell
• Water exposure
• Loose connectors
• Damaged wiring

If yes

Stop using the bike immediately.

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

If the issue remains

The motor or harness system may also require further inspection.

Please contact support.

Step 4 – Motor Harness Damage Found

Inspect the accessible motor 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 motor or controller system may also require further inspection.

Please contact support.

Step 5 – Hub Motor Damage Found

Inspect the accessible hub motor area for:

• Visible impact damage
• Abnormal movement
• Burning smell
• Water exposure
• Physical damage

If yes

Stop using the bike immediately.

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

If the issue remains

The controller or motor harness may also require further inspection.

Please contact support.

Step 6 – Check Speed Sensor Operation

Restart the bike and check whether:

• The speed display updates correctly while riding
• Motor assistance behaves normally
• The E45 error returns repeatedly

If yes – Problems continue

The issue may involve:

• Speed sensor operation
• Motor communication
• The motor harness
• The controller system

Please contact our support team with:

• Video of the display during riding
• Video showing the speed reading behaviour
• Photos of accessible connectors and wiring

If no – Everything operates normally

The issue was likely resolved during reconnection or cleaning.

Continue monitoring the bike during use.

When To Contact Support

Please contact support if:

• The E45 error remains after completing these checks
• The speed display does not work correctly
• The motor does not engage normally
• There is visible damage to the motor, controller, or harness
• The bike has been exposed to water, crash, impact, transport damage, modification, firmware issues, 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 E45 error code
• Photo of the display
• Photo/video of the motor and rear wheel area
• Photo of accessible motor harness connectors
• Screenshot of the Aventon App firmware version
• 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 speed display works correctly
• Confirmation of whether the issue happened after water exposure, crash, impact, modification, firmware update, or third-party repair
• Confirmation of the troubleshooting steps already completed

Important Safety Notes

• Do not continue riding if the E45 error remains.
• Do not use the bike if there is visible damage, overheating, smoke, or a burning smell.
• 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.