Aventon Bikes with ACU-ECU (Aventon Control Unit) – W107 Part Change TroubleshootingUpdated 2 days ago
This article explains how to troubleshoot the W107 “Part Change” warning on Aventon bikes equipped with the ACU-ECU (Aventon Control Unit).
Use this article if your bike:
- Shows warning code W107
- Displays “Part Change”
- Recently had a motor, controller, or display replaced
- Shows the warning after service or part replacement
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 warning 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, motor resistance, or persistent warning codes.
- 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 Warning Means
W107 indicates one or more bike components may have been replaced.
Part replacement involving the motor, controller, or display can trigger this warning code.
Possible Causes
- one or more parts may have been replaced
- bug in the current ECU software version
- damaged ECU
Troubleshooting Steps
Step 1 – Check Whether Parts Were Replaced
Check whether any of the following components were recently replaced:
- motor
- controller
- display
If yes
Wait 5 seconds.
The warning may disappear automatically after the bike recognizes the replaced component.
After waiting, check whether the W107 warning remains.
If no
Update the ECU software to the latest version using the Aventon app.
After the update completes, restart the bike and check whether the W107 warning remains.
If the issue clears
The warning was likely triggered by a recent part replacement.
If the issue remains
Update the ECU software to the latest version using the Aventon app.
Step 2 – Update the ECU Software
Update the ECU software to the latest version using the Aventon app.
After the update completes, restart the bike and check whether the W107 warning remains.
If the issue clears
The issue was likely caused by an ECU software bug.
If the issue remains
Replace the ECU following the ECU replacement procedure.
Step 3 – Replace the ECU
If the warning code still remains after updating the ECU software, the ECU may be faulty.
Replace the ECU following the ECU replacement procedure.
If the issue clears
The issue was likely caused by a faulty ECU.
If the issue remains
Please contact support for further diagnosis.
When To Contact Support
Please contact support if:
- the W107 warning remains after completing the steps above
- there is visible damage
- the bike does not power on
- the display does not power on
- the motor does not engage
- the issue appears related to the ECU, controller, display, or motor system
- 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 warning code
- photo of the display
- photo of the battery area
- photos of any recently replaced parts, if available
- 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 warning code remains.
- Do not ride if there is visible damage, overheating, smoke, burning smell, water exposure, or motor resistance.
- Do not open the battery, controller, ECU, 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.