Short answer: Rad bikes report the shared 21 to 25 and 30 codes (current, throttle, motor phase, motor hall, brake, communication), and Rad displays add 6, 10, 12, 15, 16 and 17 for battery voltage, motor stall, the torque sensor, the controller and a throttle held at start up; colour displays add 34 to 36 (stuck button, controller temperature, motor temperature or speed sensor). Whatever the code, do the free checks first: release the levers and throttle, restart, and check the connectors on that circuit before buying a part.
Rad Power Bikes went through Chapter 11 in late 2025 and now operates under a new owner, Life Electric Vehicles. The code table on the displays has not changed through any of that, and neither has what each number is telling you to check. Whether your bike is out of warranty or you simply want to diagnose it before you call anyone, here is the reference, grouped the way it is actually useful when you are standing over the bike.
Quick reference: Rad Power Bikes codes
Unplug, reseat and inspect connectors with the bike switched off and the battery removed. Reconnect the battery and switch on only for the steps that need power, such as reading the code, a voltage reading, a reset or testing the throttle and pedal assist, and switch off again before you touch the next plug.
| Code | What it means | Check first | Source |
|---|---|---|---|
| 21 | Abnormal current | Inspect and clean the motor and controller connections you can reach | RadRover 6 Plus manual |
| 22 | Throttle fault | Check the throttle returns to rest; test the throttle and pedal assist separately | RadRover 6 Plus manual |
| 23 | Motor phase fault | Unplug, inspect and reseat the motor cable connector | RadRover 6 Plus manual |
| 24 | Motor hall fault | Same as 23: check the motor cable connector is aligned and fully seated | RadRover 6 Plus manual |
| 25 | Brake sensor fault, or a brake held at start up | Release both levers and restart | RadRover 6 Plus manual |
| 30 | Display-to-controller communication | The cable, either end, or a protocol mismatch after a part swap | RadRover 6 Plus manual |
| 6 | Battery undervoltage | Charge fully; if it persists, inspect the battery contacts and mount for corrosion or burn marks | Rad color-display page (archived Nov 9, 2024) |
| 10 | Battery overvoltage | Restart, and use only a battery and charger made for the bike | Rad color-display page (archived Nov 9, 2024) |
| 12 | Motor stall warning | Let go of the throttle; avoid twisting it with the brakes on | Rad color-display page (archived Nov 9, 2024) |
| 15 | Torque sensor error (torque-sensor bikes) | Unplug the torque sensor connector and look for damage or moisture | Rad color-display page (archived Nov 9, 2024) |
| 16 | Controller error | Restart and note whether it returns | Rad color-display page (archived Nov 9, 2024) |
| 17 | Throttle held at start up | Let go of the throttle and switch on again | Rad color-display page (archived Nov 9, 2024) |
| 31 | Power button held down | Make sure the button springs back after the normal press that switches the bike on | RadRover 6 Plus manual |
| 34 | Walk-mode disengage fault in the RadRover manual; on colour displays, Rad's archived page reads it as a remote button held down or stuck at switch-on | Release the remote's power button once the bike starts powering on; if a button looks stuck, free it and check for damage or debris. The RadRover manual adds: switch off and on again, and if it stays, switch off and leave the bike alone to make sure nothing is pressing a button | RadRover 6 Plus manual; Rad color-display page (archived Nov 9, 2024) |
| 35 | Controller temperature sensor fault (colour displays); Rad says it typically means the controller has gone past its normal operating range | Power down and let the controller cool | Rad color-display page (archived Nov 9, 2024) |
| 36 | Motor temperature or speed sensor fault (colour displays); Rad says it typically means the motor has gone past its normal operating range | Power down and let the motor cool | Rad color-display page (archived Nov 9, 2024) |
| Others | Not on either Rad list we read, so we state no meaning | Check Rad's error-code list for your model | - |
Sources: Rad's owner's manual for the RadRover 6 Plus (hosted copy) for the codes it prints, and, for 6 to 17 and 34 to 36 on colour-display models, Rad's help center page on Color Display error codes. That page is no longer online, so we link the archived copy dated November 9, 2024. It lists the codes for the RadKick, Radster, RadExpand 5 Plus and RadWagon 5, and Rad may have changed it since, so check Rad's support site or your display's manual before acting on one of those codes. Meanings are summarized in our own words. The same codes, next to other brands that share them, are on our e-bike error code lookup.
The six codes almost every brand shares
Six of Rad's codes belong to a family that turns up across a large part of the industry, because many brands build on controllers from the same upstream platform. 21 is abnormal current, 22 is a throttle fault, 23 is a motor phase fault, 24 is a motor hall fault, 25 is a brake sensor fault or a brake being held at start up, and 30 is a communication error between display and controller. We have written about that shared code family in detail, and everything in it applies here unchanged.
If you own an older bike, that may be the whole list. A RadRover 5, for example, reports only those six.
The codes you will only meet on Rad displays
6 — Battery undervoltage. Pack voltage has dropped below what the controller will run on.
10 — Battery overvoltage. The opposite reading, and worth taking seriously rather than clearing and riding on.
12 — Motor stall warning. The motor is being asked to turn and is not turning.
15 — Torque sensor error. Only relevant on bikes fitted with a torque sensor rather than a cadence sensor.
16 — Controller error. The controller is reporting a fault in itself.
17 — Throttle on start up. The throttle was held, or is reading as held, when the bike was switched on. This is the same protective logic as code 25 on the brake side.
Buttons, temperature, and the connected features
Rad's owner's manual for the RadRover 6 Plus lists two more: 31 for the power button being held down and 34 for a walk-mode disengage fault. Rad's help page for its colour-display models, which is offline now and which we read as an archived copy dated November 9, 2024, reads 34 differently, as a remote button held down or stuck when the bike is switched on, and adds 35 for the controller temperature sensor and 36 for the motor temperature or speed sensor. For 35 and 36 that page says the part has typically gone past its normal operating range and tells you to power down and let it cool. So the same number can mean two things depending on the bike; check which list your model is on. We could not confirm meanings for other numbers, such as 40 and 50, in either of those two Rad sources, so check Rad's error-code list for your model before acting on one. Bikes with a colour display carry an additional code set of their own, documented separately from the list above.
Code 6 is the one worth reading twice
Rad's own guidance splits code 6 by how often it appears, and that split is the useful part. An intermittent undervoltage code usually points at how the bike is being ridden — heavy assist, steep ground, a pack that is low or cold. A persistent one points at hardware, and the place to look is the battery compartment: the contacts and mount where the pack meets the bike, checked for corrosion and for burn or arcing marks. That inspection costs nothing and rules in or out the most common physical cause before you start buying parts.
Getting from a code to a part
A code names a circuit, not a verdict. Codes 23 and 24 point at the motor cable and its connector at least as often as at the motor itself, so unplug, inspect and reseat before condemning anything expensive. Code 30 is a display-to-controller conversation that has stopped, which can be the cable, either end, or a protocol mismatch after someone has already swapped a part. A meter is worth more than a guess at this stage: measuring at the connector tells you whether power and signal are arriving, and that single measurement often decides which part gets replaced.
For that measurement a digital multimeter is enough; on the throttle and sensor side, compare connectors against our sensors and throttles rather than going by bike name.
When a code does end in a replacement, sourcing electrical parts is still its own problem, because Rad's official spare-parts store does not currently list controllers, displays, throttles or sensors. We keep a guide to where Rad replacement parts can still be found, and a separate one on which Rad models can take an aftermarket controller kit, which matters because not every model can.
Common questions
What does Rad error 6 mean if it only shows on hills?
Rad's guidance splits code 6 by how often it appears. An intermittent one usually reflects how the bike is ridden: heavy assist, steep ground, a pack that is low or cold. A persistent one points at hardware, so inspect the battery contacts and mount for corrosion and burn or arcing marks.
Does a Rad error code mean a part has failed?
No. A code names a circuit, not a verdict. Codes 23 and 24 point at the motor cable and its connector at least as often as at the motor, and code 30 can be the cable, either end, or a protocol mismatch. Measuring at the connector usually decides which part gets replaced.
Can I buy a replacement controller or display from Rad?
Check Rad's own spare-parts store for your model first, because its range changes. When we last checked it, in October 2026, it listed batteries, chargers, lights, tires and brake parts, but no controllers, displays, throttles, sensors, wiring harnesses or motors; we did not re-check that list for this update. See also what Rad still sells.
What the new owner sells today
Life Electric Vehicles completed its purchase of Rad's assets in early March 2026, and Rad's own store sells bikes and spare parts again. As of October 2026, those spare parts are batteries, chargers, lights, tires, brake parts and similar items; no controllers, displays, throttles, sensors, wiring harnesses or motors are listed. That could change, so check Rad's spare-parts page before you buy an electrical part anywhere else.
A code is where the work starts
Write the number down, note whether it is constant or comes and goes, and check the free things first: connectors seated, pack charged, brake levers released, nothing held at power-on. Most of these codes are pointing at a connection rather than a component, and the ones that are not will still be there after you have looked.
If your code or symptom is not covered here, our e-bike repair online guide walks you from a three-minute self-check to the right part.
This guide is part of our Rad Power Bikes repair guide and the e-bike error code lookup. Related: a Rad bike that won't turn on, a Rad throttle that does not work and brake sensors and no-power faults.
Last updated November 4, 2026: added a short answer, a quick-reference table with a source for each code and answers to common questions, and corrected code 34 to match Rad's owner's manual. Updated again the same day: code 34 now also shows the colour-display reading, and 35 and 36 were added, from Rad's help page as archived on November 9, 2024.
RideRow is an independent parts retailer and is not affiliated with, endorsed by, or sponsored by Rad Power Bikes. Rad Power Bikes and model names are trademarks of their respective owners and are used here only to identify the bikes this guide covers.