Error 30 on Bafang C965 Display

In plain English

The display and controller talk constantly through a thin data cable. This code means that conversation has stopped. Usually the display plug is loose, wet or corroded, or the cable is pinched. It's also common right after fitting a display that isn't compatible with the controller.

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. 2Reconnect the display plugEasy Switch off. Follow the display's cable to its plug, usually near the handlebar or a little way down the frame. Pull it apart, check for bent pins or water, then push it back together fully with the arrows lined up. A half-connected plug is a very common cause of display errors.
3. 3Check the cables where the handlebars turnEasy Turn the bars fully left and right while watching the cables at the front of the bike. Look for pinched, stretched or flattened spots.
4. 4Unplug 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.
5. 5Dry 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.
6. 6Did you just change a part?Moderate Displays, controllers and batteries must be a compatible match (the same communication protocol), not just share a plug. If the problem started right after you replaced something, put the old part back or check compatibility with the seller.
7. 7Try a known-good displayModerate If you can borrow a display that's compatible with your controller, swap it in. If the problem goes away, the display was at fault.
8. 8Have 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

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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

• Dielectric grease

  A thin coat on connector seals helps keep water out after you clean them.

  Link coming soon

• Display extension cable

  Replaces a pinched or damaged display cable. Must match your connector type.

  Link coming soon

• Replacement display

  Must be compatible with your controller and its protocol, not just the same plug.

  Link coming soon