The error codes E* (Error) or W* (Warning) displayed on your electric bike 's screen are essential signals to alert you of a malfunction.
For example, at Shimano , E indicates a serious error, while W is more of a mild alert or caution.
These codes vary depending on the brand, and to understand them properly, the objective of this article is simple: to offer you a clear list of the most frequent codes ( Bosch, Shimano, Yamaha, Giant, Décathlon/B'Twin , Nakamura, Néomouv, Velobecane ), to explain to you how to carry out the first troubleshooting steps, and to indicate when to call an authorized dealer or workshop for a more in-depth diagnosis.
How to Read an Error Code: The Basics
The codes can be displayed on the screen, an LED , or via a connected app, depending on the system used. The first step is always to restart the system: turn off your bike completely, wait a few moments, then turn it back on.
Also make sure that the battery is properly connected and sufficiently charged, that the connectors are clean and dry, and absolutely avoid high-pressure cleaning.
A simple check of the speed sensor and its magnet can often be enough to resolve the most common error.
Quick table of frequent codes by brand
| Brand / Ecosystem | Code | Meaning | Quick gestures | When to go to the workshop |
|---|---|---|---|---|
| Bosch | 503 | Faulty speed sensor | Check magnet alignment (5–17 mm), restart | If persists, see a Bosch dealer |
| 500 | Internal engine fault | Restart | If recurring → workshop diagnosis | |
| Shimano STEPS | E010 | Engine fault | Restart | If persistent → workshop for E-Tube diagnosis |
| W013 | Incomplete torque sensor calibration | Start without pedaling | To do; if it continues → workshop intervention | |
| Giant / SyncDrive | 0x81 | Calibration problem | Pedal for 30 seconds after checking the magnet, then try again. | If failure → reseller |
| Yamaha | — | Various faults (sensors, overvoltage, etc.) | Consult the official list, apply the instructions | If persists → workshop |
| Decathlon / B'Twin | 30 | Start error / pedestrian mode | Turn off, wait, turn back on | If persists → workshop |
| 9 | Engine or screen link error | Check connections, turn back on | If persistence, workshop recommended | |
| Nakamura | 28 | Magnet/sensor alignment | Realign | If error continues → workshop |
| 30/35/36 | Screen/battery communication error | Check cables, dry, tighten | If persists → professional intervention | |
| Néomouv / Velobecane | 21/24/25/30 | Connection or communication fault | Clean and reconnect properly | If persistence → workshop |
“Express repair” sheets by brand
Bosch (Performance Line / CX...)
Start by restarting the system. If you encounter a 503 error , check the alignment between the speed sensor and the magnet (ideally between 8 and 14 mm). If this does not resolve the issue, a Bosch dealer is recommended for further diagnosis.
Shimano STEPS
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Code W013: Make sure you turn the power back on without pressing the pedals at all. This is often the solution.
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Code E010: This is a serious engine fault. If the code returns after a restart, professional intervention via the E-Tube software is required.
Giant SyncDrive
Code 0x81 indicates a calibration error. After checking the magnet, pedal for a few seconds, then try restarting. If the bike still displays an error, a dealer can help.
Yamaha
You should consult the official list of codes (voltages, sensors). Apply the indicated solution; if the error persists, it is better to go to a workshop.
Decathlon / B'Twin
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Code 30: Usually resolved by turning the power off and then back on after a short pause.
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Code 9: Check the connections under the seat or the wiring harness, then turn the power back on. If this does not resolve the problem, a workshop will be required.
Nakamura / Néomouv / Velobecane
These brands often display errors related to sensors or communication.
Check the cables, dry them, and tighten the connectors. If the error persists, professional intervention is recommended.
A common step-by-step procedure
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Turn the bike off completely, remove the battery for 1 to 2 minutes, then turn it back on.
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Check that the connectors are clean, dry, and free of mud or moisture. Avoid cleaning with high-pressure water.
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Check the alignment of the speed sensor and its magnet (correct distance and centering), then restart.
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If the error returns (such as Bosch 500 or Shimano E010), contact an authorized workshop for diagnosis and possible software reset.
Best practices to avoid mistakes
Avoid starting the bike by pressing the pedals (this triggers W013 at Shimano ). Never use a high-pressure cleaner; dry your bike thoroughly after a ride in the rain. Regularly check the alignment of the magnet and the condition of the wiring harness; humidity and vibrations (terrain, mud) frequently damage the connectors.
When should you consult a professional or an approved workshop?
It is advisable to call a professional if you are faced with a persistent internal motor error (such as Bosch code 500 ), or if your bike has been exposed to high humidity, immersion or intensive cleaning, situations likely to damage sensitive components. In the event of a recurring breakdown despite the recommended checks (starting, magnet, connections, etc.), a diagnosis by an authorized workshop guarantees a thorough and secure check.
Ignoring these error codes as soon as they appear can lead to more serious consequences later, according to a study. . Besides, some codes like the Bosch 500 may require motor replacement or repair, and reconditioning can be costly outside of warranty .
FAQ: Electric Bike Error Codes
What are the most common error codes on my e-bike display?
The most frequently encountered codes concern the electronic brake ( E02 ), low battery voltage ( E06 / 006 / 48 ), engine faults ( E07 / 007 / 08 / 09 ), or communication problems between components such as E10 / 30. These codes often appear on several brands and indicate essential malfunctions that must be diagnosed quickly.
What does error E02 (electronic brake) mean?
This code typically indicates a fault with the electronic brake, a safety device that cuts off power assistance before mechanical braking. This could be due to a damaged cable or a damaged sensor. A visual inspection of the affected components is recommended.
My bike is displaying code E06 (low voltage). What should I do?
This code appears when the battery voltage is below the safe threshold. It indicates that the battery must be recharged immediately to avoid irreversible damage.
I have code E07 (engine fault). Is this serious?
Yes, there may be a short circuit, a faulty motor wire, or a damaged Hall sensor. Inspect the motor connections and avoid continuing to ride, or you may lose all power assistance.
What is a common cause of error 30 (display/controller communication)?
This is often a faulty connection between the display and the controller, due to loose or wet connectors. A cable check can usually identify the problem.
Can I continue driving if an error code is displayed?
It depends on the code. Some allow limited use, others completely cut off support for safety reasons. Therefore, it's best to diagnose the error before re-release.
