Rad Power Bikes RadMini 4: error 30 on the LCD display

Your RadMini 4 shows error 30 on its LCD display and the motor won't help. Rad links its RadMini error 30 guide from the RadMini 4 and RadMini ST 2 (2020) resources page, and that guide is written around a 2019 RadMini with notes for 2019 and newer bikes. The short answer: a connector somewhere is loose, dirty or damaged, or one plugged in part has failed. Reseat the battery, display and harness plugs, then unplug the rest one at a time. The RadMini Step-Thru 2 has its own error 30 guide in Rad's help center, so use that one if you have the step-thru.

Most likely cause

Rad's RadMini error 30 guide calls error 30 an unlikely event and fixes it with a connector check that confirms every plug is secure and in good shape. Rad describes the same code as a communication error in its RadCity guide, which uses the same LCD display family. A plug that has worked loose, picked up water or dirt, or has damaged pins interrupts the signals between display, controller and the parts wired to them.

Other causes to rule out

• Dirty or damaged battery or mounting tray contacts. Rad checks these first. (Rad guide)
• A failed motor, light, brake sensor, throttle or PAS sensor. If the code clears with that part unplugged, Rad says the part may need replacing. (Rad guide)
• A bike that won't power on at all. Rad's won't turn on guide for external battery bikes covers the battery key, charge level and battery connector, and mentions some RadMini models.

How to confirm

1. Turn the bike off, remove the battery and press and hold MODE on the LCD remote to drain leftover power, as Rad describes.
2. Check the battery and tray contacts. If they look fine, refit the battery and test.
3. Battery connector: near the bottom bracket, large, flat on one side, with two big prongs. Pull the halves straight apart, inspect, reconnect with the notch and pins lined up, and test.
4. Display connector: at the handlebar, a silver metal connector. Untwist the metal sleeve, pull apart, inspect, press straight together and twist the sleeve until secure.
5. Wiring harness connector: near the downtube on 2019 and newer bikes. Unplug, inspect, reconnect and test.
6. Isolation test: for each of the rest, unplug it, refit the battery and power on with it still unplugged. Rad's order is the motor (right side chainstay), taillight, second taillight on a rear rack, left brake, right brake, throttle, headlight and PAS sensor near the bottom bracket.
7. Photograph anything wet, dirty or damaged and send it to Rad Product Support.

Fix options

Reseat the connectors (easy)

Snip zip ties with flat side cutters, reseat, and replace the zip ties trimmed flush and smooth when you're done, as Rad says.

Replace the part the isolation test points to (moderate, through Rad support)

Brake sensors, the throttle, lights and the PAS sensor are plug in parts. Order the right one for your bike through Rad Product Support. Never ride with a brake sensor unplugged, since it is what cuts motor power when you brake.

Replace the harness, display or controller (pro)

If every plug is clean and nothing clears the code, a shop or Rad support should test the harness, display and controller.

Parts

• Zip ties
• E-bike connectors
• Main cable (wiring harness)
• E-bike display
• Throttle, Brake cutoff sensor or Pedal assist sensor, only the one the test points to
• E-bike controller (pro only)

When to get a pro

Get help for water or corrosion in a plug, bent pins, damaged contacts, or a code that stays after the full check. See Rad Power Bikes error codes, inspect and clean connectors and when to call a pro.

Sources

• RadMini error 30 guide, support.radpowerbikes.com
• RadMini 4 and RadMini ST 2 (2020) resources page, support.radpowerbikes.com
• RadCity guide, support.radpowerbikes.com
• won't turn on guide for external battery bikes, support.radpowerbikes.com

Stuck after these checks? Find a shop near you.