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⚠️ Error 12 — Controller Error

Error 12 is a controller fault — often just a loose connection between the controller and the motor core. Here's how to reseat everything and clear it.

July 12, 20261 min read

⚠️ Error 12 — Controller Error

Bafang 750W BBS02 Version B controller, the component that reports Error 12 What it means: A controller fault — the controller (built into the underside of the motor) has flagged an internal problem, often a lost connection between the controller and the motor core. How to fix it:
  • Reseat every connection. Unplug and replug the entire harness (display, throttle, brakes), plus the motor leads, battery, and speed sensor. Check for bent or damaged pins and align the arrows.
  • Check the controller-to-motor-core plugs. One of the internal plugs joining the controller to the motor core may have worked loose. Open the controller housing from the motor and confirm every internal plug is fully and securely seated.
  • Contact support. If reseating everything doesn't clear Error 12, the controller may need replacement — reach out and we will help you diagnose it. (Note: a truly blown controller can sometimes fail silently without any code, so if you have power loss with no drive, mention that too.)
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