E-bike error codes: what they mean and what to try first

An error code is the bike telling you which part it can't talk to or doesn't trust. Many codes point to a plug, a sensor, the throttle or the battery, and the code list for your system is the fastest way to know which.

First, find out which system you have

The code only means something next to the right list. Codes differ by system, by display and sometimes by model, so the same number can mean different things on two bikes. Write the code down exactly, including letters, before you turn anything off.

Safe things to try

• Restart the system. Bafang's display manual says to restart first for any error, then contact your dealer if it stays (Bafang C271 manual).
• Charge the battery. Some codes simply mean low voltage, such as Bafang 42 (Bafang C271 manual).
• With the bike off, reseat the battery and check the plugs between the handlebar and the motor. Pull each one straight apart, don't twist, and push it back with the arrows lined up (Lectric quick plug check).
• Make sure both brake levers spring all the way back. A lever that stays pulled can keep the brake cut-off active (Velotric troubleshooting).
• Check the wheel's speed sensor and magnet. A dirty or misaligned magnet can lose the speed signal (Himiway).
• If a code says the motor, controller or battery is too hot, switch off and let it cool (Bafang C271 manual).

Error codes: a few examples

These are from Bafang's C271 display manual. Other Bafang displays and other systems use different lists (Bafang C271 manual).

• 04: throttle fault. 05: throttle not back in its rest position.
• 10: motor overheated. 14: controller overheated.
• 21: speed sensor error.
• 30: communication problem between parts.
• 33: brake signal error, on bikes with brake sensors.
• 42: battery voltage too low.
• 46: battery too cold.

Lectric lists E007 as a motor fault, usually checked at the motor cable plug, and E008 as a throttle error, usually the throttle plug (Lectric E007, Lectric E008).

Where the official lists live

• Shimano: its STEPS FAQ points to Shimano's online error code lookup, and its E-TUBE PROJECT Cyclist app shows codes on your phone (Shimano STEPS FAQ).
• Bosch: the Bosch downloads page points to the Bosch Help Center for full manuals. Bosch dealers read codes with a diagnostic tool (Bosch downloads, Bosch owner guide).
• Bafang: the display manual for your display model (Bafang C271 manual).
• Direct-to-consumer brands usually publish their own list in their help center, as Lectric does.

Stop and get help if

• The code comes back after a restart and a full charge. Velotric says to contact support if the same code returns after a restart and battery reseat (Velotric troubleshooting).
• The code points at the battery's cells or voltage. Bafang's fix for most battery codes is a new battery, not a repair (Bafang C271 manual). See battery won't charge.
• The fix needs a dealer tool or a firmware update. Bafang uses its BESST tool, Bosch dealers use a diagnostic tool (Bafang C271 manual, Bosch owner guide).

Sources

• C271 display user manual, Bafang
• Quick connect plug check, Lectric eBikes
• Error code E007, Lectric eBikes
• Error code E008, Lectric eBikes
• Electric bike troubleshooting guide, Velotric
• Why does my ebike motor keep cutting out, Himiway
• Shimano STEPS FAQ, Shimano
• Downloads, Bosch eBike Systems
• eBike owner's guide (US), Bosch eBike Systems

Stuck after these checks? Find a shop near you.