Error 12 on 850C Display

In plain English

The controller has a circuit that measures current, and this code means that circuit has a fault. It's an internal problem, so there's little to do yourself beyond ruling out loose connections and water.

Work from the top. Steps go from free and easy to shop jobs. Switch the bike off before touching any connector. Tick each step as you go. Your progress is saved on this device.

1. 1Turn it off and on againFree Switch the display off, wait 30 seconds, then switch it back on. If the code clears, note what you were doing when it appeared, in case it comes back.
2. 2Unplug and check the main connectorsEasy Switch off and remove the battery. Find the round waterproof plugs along the cables (usually near the handlebar, down the frame and near the motor). Pull each one apart, look for bent pins, water, green corrosion or melted plastic, then push it back together fully with the arrows lined up.
3. 3Dry the bike out if it got wetModerate If the problem started after rain or washing, remove the battery and leave the bike somewhere warm and dry for 24 to 48 hours, then test again.
4. 4Ask a Bafang dealer to read the faultShop job Bafang dealers have a diagnostic tool that reads detailed fault data and can update firmware. It often pins down internal faults quickly.
5. 5Have the controller testedShop job If the wiring checks out, the controller may be faulty. A shop can test it and replace it if needed.

Parts you might need

As an Amazon Associate I earn from qualifying purchases. These links go straight to Amazon.

Only buy a part if the free steps didn't fix it. Always match the voltage and connector type to your bike.

• Electrical contact cleaner spray

  Cleans dirt and corrosion from connector pins and battery contacts.

  Link coming soon