Aventon Mid-Drive Bikes – E40 Display Fault TroubleshootingUpdated 2 days ago
This article explains how to troubleshoot the E40 “Display Fault” error on Aventon mid-drive bikes.
Use this article if your bike:
- Shows error code E40
- Displays “Display Fault”
- Has display communication or functionality issues
- Experiences intermittent display behavior
- Does not properly display ride information
If you are unsure about any step or notice anything unsafe, stop troubleshooting and contact support.
Before You Start
Please prepare the following:
- order number
- Aventon model
- photo or video of the issue
- photo of the E40 error code
- when the issue first appeared
- whether the bike powers on
- whether the battery charges
- whether the display turns on
- whether the motor engages
- whether the issue happened after charging, riding, transport, storage, water exposure, crash, impact, modification, or third-party repair
- photos of any visible damage
Safety Warnings
- Do not continue riding if the bike has visible damage, overheating, smoke, burning smell, water exposure, or a persistent error code.
- 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
E40 indicates a display fault involving the display or display harness.
The issue may be caused by:
- an internal display warning or error
- damaged display components
- damaged display harness connections
Possible Causes
- internal display warning or error
- damaged display
- damaged display harness
Troubleshooting Steps
Step 1 – Disconnect, Inspect, and Clean the Display Components
Disconnect, inspect, and clean:
- display
- display harness
After cleaning and reconnecting the components, restart the bike and check whether the E40 code remains.
If the issue clears
The issue was likely caused by a loose or dirty connection.
If the issue remains
Inspect the display and display harness for visible damage.
Step 2 – Inspect for Visible Damage
Inspect the following components for visible damage:
- display
- display harness
If the display is damaged
Replace the display.
After replacement, restart the bike and check whether the E40 code remains.
If the display harness is damaged
Replace the display harness.
After replacement, restart the bike and check whether the E40 code remains.
If the issue clears
The issue was likely caused by the damaged component that was replaced.
If the issue remains
Replace the remaining display communication component.
Step 3 – Replace the Display Harness
Replace the display harness if:
- the issue remains after replacing the display
- the harness shows visible damage
- communication issues continue after reconnecting the display
After replacement, restart the bike and check whether the E40 code remains.
If the issue clears
The issue was likely caused by a faulty display harness.
If the issue remains
Replace the display.
Step 4 – Replace the Display
Replace the display if:
- the issue remains after replacing the display harness
- the display shows visible damage
- the display fault continues after reconnecting components
After replacement, restart the bike and check whether the E40 code remains.
If the issue clears
The issue was likely caused by a faulty display.
If the issue remains
Please contact support for further diagnosis.
When To Contact Support
Please contact support if:
- the E40 error remains after completing the steps above
- there is visible damage
- the battery does not charge
- the bike does not power on
- the display does not power on
- the motor does not engage
- the issue appears related to the display, display harness, connectors, or internal wiring
- 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
- you need warranty, repair, replacement part, refund, or replacement support
If the issue remains after this step, please contact our support team and include the photos/videos listed below.
What To Send Support
Please send:
- order number
- Aventon model
- photo or video of the E40 error code
- photo of the display
- photo of the battery area
- photo of accessible connectors or harnesses, if safe
- photos of visible damage
- confirmation of whether the bike powers on
- confirmation of whether the battery charges
- confirmation of whether the display turns on
- confirmation of whether the motor engages
- confirmation of whether there was water exposure, crash, impact, modification, or third-party repair
- list of troubleshooting steps already completed
Important Safety Notes
- Do not continue riding if the E40 error remains.
- Do not ride if there is visible damage, overheating, smoke, burning smell, water exposure, or motor resistance.
- Do not open the battery, controller, display, 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.