Find your bike's brand or display below, read the row for your code, and do the free check in that row before you buy anything. The same number means different things on different systems, so identify the display first. Every meaning is written in our own words and checked against the maker's own manual or help pages, or at least two independent sources; each row links its sources, and where the sources disagree, the row says so.
Safety first. Turn the bike off and remove the battery before you unplug any connector, and do not keep powering up a bike that shows a short-circuit or overheating code. A code on its own does not prove that a part has failed.
How to use this table
- Write the code down exactly, including any letter (E, ERROR, 0x) and leading zeros, and note whether it shows at switch-on or only under load.
- Identify the system. Use the bike's brand, or the display model named on the display or in the bike's manual (KT-LCD3, SW900, 750C, DP C244 and so on). Not sure? See how to identify your display model.
- Do the check-first step. Switch off and remove the battery before you unplug or inspect any connector. Start with the plug, cable or setting the row names.
- Restart and see if it clears. If it comes back, read the "When it is likely the part" column: it says what has to be true before a part is the answer, and the linked guide has the test. You can also try our diagnosis tool.
Jump to your brand or display
Shared 21–30 codes
Rad Power Bikes
Aventon
Lectric
Heybike
Velotric
Ride1Up
Jasion
Gotrax
Bafang
APT 750C / 850C
KT (Kunteng)
SW900 and similar
Same number, different meaning
Sources
The shared 21–30 codes (many brands)
Many e-bikes report the same six two-digit codes. Display makers King-Meter (KM5S, KM6S, E5227) and APT (the 5S-protocol 800S) print them in their manuals, and the same six show up in owner's manuals from Rad Power Bikes, Aventon (Pace 500, Aventure), Velotric (Go 1, Packer 1), Jasion and Gotrax (F3 V2). Bafang and a few others reuse some of these numbers for different parts, so check your own system's table below too.
| Code | What it means (our words) | Check first | When it is likely the part | Guide | Source |
|---|---|---|---|---|---|
| 21 | Current fault: the controller has detected abnormal current | Let the bike rest a few minutes and restart; reseat the motor cable and look for chafed or dirty wiring | Only if it keeps returning with clean, undamaged wiring. Makers name different parts next (Gotrax's F3 V2 manual the motor, Velotric the controller), so ask yours before buying | The 21–30 code family | King-Meter E5227 guide; King-Meter KM6S guide; RadRover manual; Gotrax F3 V2 manual; Velotric 21–30 guide |
| 22 | Throttle fault | Check the throttle springs back; reseat its plug; look for a pinched or cut cable at the handlebar | The plug and cable are fine and the throttle fails the voltage test in the guide | Throttle test with a multimeter | King-Meter KM6S guide; Aventon Pace 500 manual; Gotrax F3 V2 manual |
| 23 | Motor phase fault: one or more of the motor power (phase) wires is damaged or disconnected | Reseat the main motor connector; look for a pushed-back pin, water or crush damage | The connector and cable are sound and the code still returns: the motor or the controller, so test before you buy | Water in the motor connector | King-Meter E5227 guide; Aventon Pace 500 manual; Gotrax F3 V2 manual |
| 24 | Motor Hall fault: the position sensors inside the motor are not reporting cleanly | Same motor connector first: Rad and Aventon both send you to the main motor cable for this code; then test the Hall signals | A Hall signal fails the test in the guide while the connector is known good | How to test Hall sensors | King-Meter KM6S guide; APT 800S spec; Aventon Pace 500 manual; Rad color-display page (archived) |
| 25 | Brake signal: a brake cut-off reads as applied, or a lever was held while the bike switched on | Release both levers fully and restart; if it stays, unplug one brake sensor at a time to find the stuck side | Narrowed to one side's brake circuit: check that lever returns fully, its adjustment and its wiring before replacing the sensor or lever | The brake sensor guide | King-Meter E5227 guide; RadRover manual; Aventon Aventure manual |
| 30 | Communication fault: the display and the controller have stopped talking | Inspect the display cable and its plugs, especially where it bends at the head tube; if a part was just swapped, check it uses the same protocol | Only after the cable and plugs check out. Makers differ on which part is next (Gotrax's F3 V2 manual the display, Ride1Up rates the controller most likely) | Why a new display may not work | King-Meter KM5S guide; Aventon Pace 500 manual; Gotrax F3 V2 manual; Ride1Up Error 30 |
Rad Power Bikes
Rad's RadRover owner's manual lists the shared six plus 31 and 34. Rad's help page for its color-display models (RadKick 7-Speed, RadKick Belt Drive, Radster Trail, Radster Road, RadExpand 5 Plus and RadWagon 5) adds codes for battery voltage, motor stall, the torque sensor, the controller, a throttle held at switch-on, stuck buttons and temperature. That page is no longer online; we read and link the archived copy dated November 9, 2024.
| Code | What it means (our words) | Check first | When it is likely the part | Guide | Source |
|---|---|---|---|---|---|
| 21–25, 30 | Same meanings as the shared family above; on Rad, 25 also appears if a brake lever is held while the bike switches on | Release both levers and restart, then work through the shared-family checks | As in the shared table. For 21 and 23 on color displays Rad first has you power down and let the motor cool; its page sends 23 to Rad support if it returns away from hills | Rad error codes | RadRover manual; Rad color-display page (archived) |
| 6 | Battery voltage too low (color-display models) | Charge the battery fully, then retest | Rad calls this rare; if it keeps showing on a fully charged pack, it is a battery question for Rad | Rad error codes | Rad color-display page (archived) |
| 10 | Battery voltage higher than the system expects (color-display models) | Restart; use only a battery made for the bike | Rad names two causes: a battery Rad did not approve, or a controller problem | Rad error codes | Rad color-display page (archived) |
| 12 | Stall warning: the throttle is asking for power but the motor is not turning | Let go of the throttle; avoid twisting it with the brakes on, or holding light throttle on a hill instead of stopping | Not a part fault by itself; a restart resets it | Rad throttle not working | Rad color-display page (archived) |
| 15 | Torque sensor fault (torque-sensor models) | Unplug the torque sensor connector at the controller and look for damage or moisture; check the throttle-to-harness cable as well | It returns with a clean, dry connector: the sensor circuit needs testing before you buy a part | Rad error codes | Rad color-display page (archived) |
| 16 | The controller is reporting an internal failure | Restart; if it stays, run Rad's connector check for your model to isolate the part | Only after the connector check rules out the other parts | Rad error codes | Rad color-display page (archived) |
| 17 | The throttle was held, or reads as held, when the bike switched on | Let go of the throttle and switch on again | It shows with the throttle untouched: test the throttle | Rad throttle not working | Rad color-display page (archived) |
| 31 | Power button held down or stuck (RadRover manual) | Make sure the button springs back after the normal press that switches the bike on | Still there with the button released and moving freely: diagnose further before buying a part | Rad error codes | RadRover manual |
| 34 | Two meanings: a walk-mode release fault in the RadRover manual; a remote button held or stuck at switch-on on color displays | Release the buttons once the bike starts; free a stuck button and check for debris under it | Still there with every button released and moving freely: diagnose further before buying a part | Rad error codes | RadRover manual; Rad color-display page (archived) |
| 35 | Controller temperature (color displays): Rad says the controller has gone past its normal range | Power down and let the controller cool | Not a part fault by itself | Rad error codes | Rad color-display page (archived) |
| 36 | Motor temperature or speed sensor (color displays); Rad says it usually means the motor got too hot | Power down and let the motor cool | Not a part fault by itself | Rad error codes | Rad color-display page (archived) |
| Other numbers | Not on either Rad list we read, so we do not state a meaning here | See Rad's error code list for your model | Unknown until the code is identified | Rad error codes | RadRover manual; Rad color-display page (archived) |
Aventon
Aventon's codes depend on the drive system. Dealer and retailer guides (Electric Kicks, Upway) split them into hub-drive, mid-drive and smart-control-unit (ACU) bikes, which add lock and connectivity codes. Older Aventon manuals (the 2018 Pace 500 and the Aventure) list the codes they cover without the E.
| Code | What it means (our words) | Check first | When it is likely the part | Guide | Source |
|---|---|---|---|---|---|
| E21 / 21 | Current fault (abnormal current) | Switch off and let it cool; clean and reseat the motor and controller plugs | It comes back on flat ground after the plugs are clean and the bike has cooled: the motor or controller is the suspect | Aventon error codes | Aventon Aventure manual; Aventon Pace 500 manual; Electric Kicks Aventon index; Electric Kicks E21 |
| E22 / 22 | Throttle fault | Check the throttle returns to rest; look for a cut or frayed throttle cable | The cable is sound and the throttle fails the voltage test in the guide | Aventon throttle and error 22 | Aventon Aventure manual; Aventon Pace 500 manual; Electric Kicks Aventon index |
| E23 / 23 | Motor phase fault | Reconnect the rear hub motor cable firmly and clean any grit from it; the Pace 500 manual notes this code after a rear wheel was removed | The cable is clean, seated and undamaged and the code returns: test the motor and controller | Aventon error codes | Aventon Aventure manual; Aventon Pace 500 manual; Electric Kicks Aventon index |
| E24 / 24 | Motor Hall fault | Reseat the motor cable; on the Pace 500 also check the cadence sensor plug | A Hall signal fails the test in the guide while the cable is known good | How to test Hall sensors | Aventon Aventure manual; Aventon Pace 500 manual; Electric Kicks Aventon index |
| E25 / 25 | Brake switch fault, or a brake held while the bike switches on | Restart with hands off the levers; if it stays, check the lever's sensor | The Pace 500 manual says a lever damaged in a crash may need replacing | The brake sensor guide | Aventon Aventure manual; Aventon Pace 500 manual; Electric Kicks Aventon index |
| E26 / 26 | Overheat protection | Stop and let the system cool before riding on | Not a part fault by itself | Aventon error codes | Aventon Aventure manual; Electric Kicks E26; Upway Aventon guide |
| E27 / 27 | Motor lock protection | Switch off, check nothing is stopping the rear wheel from turning, clear anything jammed and restart | The wheel spins freely and the code stays: ask Aventon before buying a part | Aventon error codes | Aventon Aventure manual; Electric Kicks E27; Upway Aventon guide |
| E28 | Low-voltage protection | Charge the battery fully and retest | It keeps showing on a full charge: a battery question for Aventon | Aventon error codes | Electric Kicks E28; Upway Aventon guide |
| E29 / 29 | Over-voltage protection | Confirm the battery and charger are the ones made for the bike, then restart | Even with the right battery and charger it can still be the battery or the controller; ask Aventon if it persists | Aventon error codes | Aventon Aventure manual; Electric Kicks E29; Upway Aventon guide |
| E30 / 30 | Controller-to-display communication fault | Inspect every cable and plug between the display and the controller | The cables and plugs are sound: see the controller-or-display guide before buying | Controller, display or both | Aventon Aventure manual; Aventon Pace 500 manual; Electric Kicks E30 |
| E31 | Battery communication fault | Remove and refit the battery, check its contacts and the display harness, then restart | It persists with clean contacts and an undamaged harness: ask Aventon which part is next | Aventon error codes | Electric Kicks E31; Upway Aventon guide |
| E41, E42, E44 | Two published lists disagree: Electric Kicks names the controller (E41), motor (E42) and torque sensor (E44); Upway names the motor, torque sensor and battery | If your list names the battery for E44 (Upway's does), stop using that battery and contact Aventon rather than testing it yourself. Otherwise, with the bike off and the battery removed, reseat the controller, display, motor and sensor plugs, then restart | Do not buy a part until Aventon confirms which one your model's code names | Aventon error codes | Electric Kicks E41; Electric Kicks E42; Electric Kicks E44; Upway Aventon guide |
Lectric (XP 3.0 and XP4)
Lectric's XP 3.0 and XP4 manuals print the same eight codes, and most point to one quick-plug connector. Other Lectric models may differ; if your bike came with its own manual, that manual wins.
| Code | What it means (our words) | Check first | When it is likely the part | Guide | Source |
|---|---|---|---|---|---|
| E003 | Pedal-assist (PAS) sensor fault | Unplug the PAS quick plug with a straight pull, check the pins, and refit with the arrows lined up | The plug is clean and seated and the code returns: test the sensor and its wiring | Lectric error codes | Lectric XP4 manual; Lectric XP 3.0 manual |
| E006 | Battery voltage too low | Charge fully | It returns soon after a full charge: a battery and charger question for Lectric | Lectric error codes | Lectric XP4 manual; Lectric XP 3.0 manual |
| E007 | Motor fault | Reseat the motor quick plug and look for bent pins or dirt | The plug is sound and the code returns: test the motor before buying | Lectric E007 motor fault | Lectric XP4 manual; Lectric XP 3.0 manual |
| E008 | Throttle fault | Reseat the throttle quick plug and look along its cable for damage | The plug and cable are sound and the throttle fails the voltage test | Lectric E008 throttle fault | Lectric XP4 manual; Lectric XP 3.0 manual |
| E009 | Controller fault | Check the controller connections; do not open sealed components | Only after the connections check out | Lectric error codes | Lectric XP4 manual; Lectric XP 3.0 manual |
| E010 | The display is not receiving data | Reseat the display quick plug | The plug is sound: see the controller-or-display guide | Lectric E010 and E011 | Lectric XP4 manual; Lectric XP 3.0 manual |
| E011 | The display is not sending data | Reseat the display quick plug | The plug is sound: see the controller-or-display guide | Lectric E010 and E011 | Lectric XP4 manual; Lectric XP 3.0 manual |
| HOT | Over-temperature | Stop riding and let the bike cool | Not a part fault by itself | Lectric error codes | Lectric XP4 manual; Lectric XP 3.0 manual |
Heybike (Mars 3.0 and Ranger 3.0 Pro)
Both manuals print the same six-line table. It names the fault but gives no fix per code, so the checks below are ours. Older Heybike models may use a different display and different codes.
| Code | What it means (our words) | Check first | When it is likely the part | Guide | Source |
|---|---|---|---|---|---|
| E60 | Controller fault | Reseat the plugs at the controller | Only after the plugs check out; it is then a controller question for Heybike | Heybike controller replacement | Heybike Mars 3.0 manual; Heybike Ranger 3.0 Pro manual |
| E61 | Throttle fault | Reseat the throttle plug, check the cable near the bar, and check the drive-mode setting | The plug and cable are sound and the throttle fails the voltage test | Heybike throttle and E61 | Heybike Mars 3.0 manual; Heybike Ranger 3.0 Pro manual |
| E62 | Communication fault (the manual does not say between which parts) | Start with the display cable and its plug | The cable is sound: see the controller-or-display guide | Heybike error codes | Heybike Mars 3.0 manual; Heybike Ranger 3.0 Pro manual |
| E63 | Battery voltage too low | Charge fully and make sure the battery is seated in its tray | It keeps showing on a full charge: a battery question for Heybike | Heybike error codes | Heybike Mars 3.0 manual; Heybike Ranger 3.0 Pro manual |
| E64 | Brake fault | Squeeze and release both levers, make sure neither sticks partly on, and check the lever plugs | Narrowed to one side's brake circuit: check that lever returns fully, its adjustment and its wiring before replacing the sensor or lever | The brake sensor guide | Heybike Mars 3.0 manual; Heybike Ranger 3.0 Pro manual |
| E65 | Motor or Hall sensor fault | Reseat the motor plug | A Hall signal fails the test in the guide while the plug is known good | Heybike E65 Hall test | Heybike Mars 3.0 manual; Heybike Ranger 3.0 Pro manual |
Velotric
Velotric publishes two lists on its help center. The two-digit codes 21–30 are for the Discover 1, Nomad 1 (and Plus versions), Go 1, Packer 1, Fold 1 and Fold 1 Lite. The E-codes, grouped by component, are for newer models including the Discover 2, Nomad 2, Nomad 2X, Breeze 1, Summit 1, Fold 1 Plus and Triker. Velotric notes some screens show OX instead of E; the number means the same. Velotric's own fix order is in the last column.
| Code | What it means (our words) | Check first | When it is likely the part | Guide | Source |
|---|---|---|---|---|---|
| 21 | Abnormal current, or a damaged power transistor (MOS) in the controller | Inspect the controller connector and cable for damage | Velotric: a damaged connector or cable is replaced; if both are fine, the controller is next | Velotric error codes | Velotric 21–30 guide; Velotric Go 1 manual |
| 22 | Throttle fault | Inspect the throttle connector and cable | Velotric: the throttle itself only when its connector and cable are undamaged | Throttle test with a multimeter | Velotric 21–30 guide; Velotric Go 1 manual |
| 23 / 24 | Motor phase missing / motor Hall fault | Inspect the motor cable and reconnect it | Velotric: the motor only when the cable shows no damage | How to test Hall sensors | Velotric 21–30 guide; Velotric Go 1 manual |
| 25 | Abnormal brake signal | Check the brake lever connectors and that the brakes work normally | Velotric replaces the brake lever when its connector is damaged | The brake sensor guide | Velotric 21–30 guide; Velotric Go 1 manual |
| 26 | Battery voltage too low | Check the battery indicator and charge it (Velotric suggests 4–5 hours) before switching on again | It will not clear after a full charge: ask Velotric | Velotric error codes | Velotric 21–30 guide; Velotric Go 1 manual |
| 27 / 28 | Over-voltage protection / speed-limit protection | Nothing to check first: Velotric routes both to its support team | Ask Velotric | Velotric error codes | Velotric 21–30 guide; Velotric Go 1 manual |
| 29 | Cadence sensor fault | Inspect the cadence sensor connector and cable | Velotric: a new cadence sensor when the connector or cable is damaged | Cadence sensor troubleshooting | Velotric 21–30 guide; Velotric Go 1 manual |
| 30 | Communication fault | Check every connector and cable for damage | A damaged part is replaced; if none is damaged, ask Velotric | Velotric error codes | Velotric 21–30 guide; Velotric Go 1 manual |
| E02, E03, E04 | Communication: the display (E02), display to battery (E03), display to motor controller (E04) | Check the harness for loose or broken sections and the plugs for bent pins or debris; for E03 also check the battery's power-plug pins | Velotric: if two of these show together, the display is replaced first, then the motor controller | Velotric error codes | Velotric E-code guide |
| E10, E11, E18 | Display internal faults: light sensor (E10), 5 V supply (E11), Bluetooth (E18) | Restart and note whether it comes back; Velotric lists no wiring check for these | Velotric's fix for each is a new display | Velotric error codes | Velotric E-code guide |
| E12, E13 | Front-light supply from the display too high (E12) or too low (E13) | If the front light still switches on and off, Velotric says no action is needed | The light will not switch: Velotric replaces the display | Velotric error codes | Velotric E-code guide |
| E14, E16, E17 | Front-light circuit: open circuit (E14), over-current (E16), short circuit (E17) | Inspect the front-light harness and plug for damage, bent pins or debris | Velotric: a new front light only after the harness checks out | Velotric error codes | Velotric E-code guide |
| E20, E21 | Supply to the display too high (E20) or too low (E21) | E21: charge the battery. E20: Velotric says no action is needed; it usually comes from fast coasting while the motor is jammed in one direction, or from a non-Velotric battery or outside supply | Not a part fault by itself | Velotric error codes | Velotric E-code guide |
| E30–E34 | Controller internal faults: current sensor, power-transistor (MOS) drive voltage high or low, MOS short circuit, 5 V supply | Nothing to check outside the controller; note the code | Velotric's fix is a new motor controller | Velotric error codes | Velotric E-code guide |
| E35, E36, E37 | Throttle circuit: open circuit (E35), over-current (E36), ground-wire protection (E37) | Inspect the throttle harness and plug for damage, bent pins, corrosion or debris | Velotric: a new throttle only after the harness and pins check out | Throttle test with a multimeter | Velotric E-code guide |
| E40 | Over-current protection | Stop, switch off and restart | It keeps coming back: Velotric replaces the motor controller | Velotric error codes | Velotric E-code guide |
| E41, E42 | Throttle not returned to rest (E41); runaway (anti-flyaway) protection (E42) | Let the throttle return to rest; check it is not rubbing on another part and adjust its position | A throttle whose return spring is too weak is replaced (Velotric) | Throttle test with a multimeter | Velotric E-code guide |
| E43, E44 | Low-voltage protection (E43) / over-voltage protection (E44) | E43: charge the battery. E44: Velotric says no action is needed; it usually comes from fast coasting while the motor is jammed in one direction, or from a non-Velotric battery or outside supply | Not a part fault by itself | Velotric error codes | Velotric E-code guide |
| E45, E5A | Controller heat protection (E45) / motor overheating (E5A) | Stop and rest for more than 20 minutes so it can cool | Not a part fault by itself; with E45, power drops and then stops while it is too hot | Velotric error codes | Velotric E-code guide |
| E46 | Stall protection | Stop, let the throttle return to rest, then ride on | Not a part fault by itself | Velotric error codes | Velotric E-code guide |
| E47 | Brake sensor fault | Unplug one side's brake sensor connector at a time and see which one clears the code; inspect that sensor's wiring | Velotric's order: that side's sensor, then the integrated cable, and only last the controller, which it calls very rare. On the Summit 1, adjust that lever's reach screw before replacing the sensor | The brake sensor guide | Velotric E-code guide |
| E50 | 5 V supply over-current | Velotric checks the torque sensor and motor harnesses for damage or a short, then unplugs each in turn | Whichever unplugged part clears the code is the one Velotric replaces | Velotric error codes | Velotric E-code guide |
| E51–E56 | Motor group: Hall channel A, B or C (E51–E53), shorted phase line (E54), speed sensor (E55), motor temperature sensor (E56) | Inspect the motor harness and connector for damage, bent pins or debris | Velotric: the motor next, and the controller only if a new motor does not clear it | How to test Hall sensors | Velotric E-code guide |
| E60, E62, E63 | Torque sensor: open circuit (E60), abnormal output (E62), abnormal cadence signal (E63) | Run Sensor Calibration in the display settings and restart; for E62 and E63, pedal two turns and restart first; then inspect the torque sensor harness and plug | Velotric: a new torque sensor next; if the code survives that and a restart, the controller | Velotric error codes | Velotric E-code guide |
| E61 | Torque sensor over-current | Run Sensor Calibration and restart; inspect the torque sensor harness for damage or a short; then unplug the sensor and see if the code clears | It clears with the sensor unplugged: the torque sensor. It stays: restart, then the controller (Velotric) | Velotric error codes | Velotric E-code guide |
| E64 | Torque sensor zero-point fault | Run Sensor Calibration in the display settings | Velotric: the controller if calibration will not run; the torque sensor if, after calibration, there is still no power and the torque reading does not change when you pedal | Velotric error codes | Velotric E-code guide |
| E70, E71, E73–E77 | Light circuits: rear light open circuit or over-current (E70, E71); front light over- or under-voltage, open circuit, over-current or short (E73–E77) | Inspect the light's harness and plug | Velotric: a new light only after the harness checks out; for E73 and E74, the controller if the light will not switch | Velotric error codes | Velotric E-code guide |
Ride1Up
Ride1Up's support site has articles for Errors 21, 23 and 24, 25 and 30. The Revv1 has its own table, where several numbers mean something else, so check which list matches your bike.
| Code | What it means (our words) | Check first | When it is likely the part | Guide | Source |
|---|---|---|---|---|---|
| 21 | Voltage or current protection | Reset the display to its defaults; remove the battery, inspect the terminals and refit it gently | It persists: Ride1Up rates the internal controller as the most likely cause, then the motor; contact Ride1Up | Ride1Up error codes | Ride1Up Error 21 |
| 23 / 24 | Motor, motor cable or internal controller problem (Ride1Up covers both codes in one article without defining each) | At the chain stay, make sure the 9-pin motor cable is aligned and fully seated; then follow the cable for cuts or crushing | Ride1Up says a new controller, motor cable or motor is needed only in rare cases | Ride1Up error codes | Ride1Up Error 23 and 24 |
| 25 | A brake lever reads as pressed; holding a lever while switching on is one cause Ride1Up names | Switch on with hands off the levers; check both levers spring back; unplug the sensors one at a time to find the side | A damaged lever or sensor wire: a new sensor or lever | The brake sensor guide | Ride1Up Error 25; Ride1Up brake sensor article |
| 30 | Display and controller not communicating | Reset the display, then follow the display wire to the controller looking for damage | Ride1Up rates the internal controller as the most common cause, then display settings or wire damage | Ride1Up error codes | Ride1Up Error 30 |
| Revv1: 4, 5 | Throttle not in its rest position / throttle not working | Check the throttle cable connection and that it sits at rest | The first steps do not clear it: contact Ride1Up | Ride1Up error codes | Ride1Up Revv1 code page |
| Revv1: 7 | Over-voltage: a sensor is reporting an over-high voltage, or has failed | Check the cadence sensor and the throttle | The first steps do not clear it: contact Ride1Up | Ride1Up error codes | Ride1Up Revv1 code page |
| Revv1: 8, 9 | Motor Hall cable / motor phase cable fault | Check the motor cable for damage or a loose plug; disconnect and reconnect it | The cable is sound and the code returns: contact Ride1Up | Ride1Up error codes | Ride1Up Revv1 code page |
| Revv1: 10, 13, 14 | Motor, battery or controller too hot | Switch off and let it cool; for 14 also inspect the controller connections | Not a part fault by itself | Ride1Up error codes | Ride1Up Revv1 code page |
| Revv1: 11 | Motor temperature sensor fault | Nothing to check outside the motor | Ride1Up says the motor needs replacing | Ride1Up error codes | Ride1Up Revv1 code page |
| Revv1: 15 | Controller temperature sensor fault | Inspect the controller connections first | Ride1Up replaces the controller only if the connections are fine | Ride1Up error codes | Ride1Up Revv1 code page |
| Revv1: 12 | Current sensor fault | Inspect the controller cables | The cables are sound: contact Ride1Up | Ride1Up error codes | Ride1Up Revv1 code page |
| Revv1: 21, 26 | Speed sensor / speed sensor signal | Check the rear wheel connection (21) or the motor wiring (26) | For 26, Ride1Up's next step after the wiring is a new motor | Ride1Up error codes | Ride1Up Revv1 code page |
| Revv1: 23, 24 | Headlight / headlight sensor fault (not a motor code on this bike) | Check the connections at the light | The connections are sound: contact Ride1Up | Ride1Up error codes | Ride1Up Revv1 code page |
| Revv1: 25 | Brake sensor needs adjusting | Unplug the brake cut-off wires one at a time to find the side | That side's sensor is adjusted, or replaced if adjusting does not clear it | The brake sensor guide | Ride1Up Revv1 code page |
| Revv1: 30 | Display and controller not communicating | Check the display and controller connections | The connections are sound: contact Ride1Up | Ride1Up error codes | Ride1Up Revv1 code page |
| Revv1: 39 | Internal controller fault | Nothing to check first | Ride1Up's fix is a new motor controller | Ride1Up error codes | Ride1Up Revv1 code page |
Jasion (EB7 and X-Hunter)
Both manuals print the shared six with brief labels and no fixes, so the checks below are ours. For other Jasion models, check the manual for your exact model.
| Code | What it means (our words) | Check first | When it is likely the part | Guide | Source |
|---|---|---|---|---|---|
| 21 | Current fault | Charge the battery and make sure it is fully seated; then the shared-family checks | As in the shared table | Jasion error codes | Jasion EB7 manual; Jasion X-Hunter manual |
| 22 | Throttle fault | Reseat the throttle plug at the handlebar | The plug is sound and the throttle fails the voltage test | Jasion error codes | Jasion EB7 manual; Jasion X-Hunter manual |
| 23 / 24 | Motor / motor signal fault (Jasion does not say how the two differ) | Reseat the motor plug and check for damaged wiring | The plug and wiring are sound: test the motor before buying | Jasion error codes | Jasion EB7 manual; Jasion X-Hunter manual |
| 25 | Brake lever fault | Check both levers spring fully back and nothing pinches the cable | Narrowed to one side's brake circuit: check that lever returns fully, its adjustment and its wiring before replacing the sensor or lever | Jasion error codes | Jasion EB7 manual; Jasion X-Hunter manual |
| 30 | Communication fault | Start with the display cable | The cable is sound: see the controller-or-display guide | Jasion error codes | Jasion EB7 manual; Jasion X-Hunter manual |
Gotrax
This page covers three Gotrax code tables: the E-codes on the EBE2 and EBE4, the ERROR codes in the F3 V2 manual, and the Mustang's hex codes. Gotrax asks owners to stop riding and contact its support when any code appears. LED-only models (EBE1, Alpha, Emerge, Endura, Traveler) cannot show codes.
| Code | What it means (our words) | Check first | When it is likely the part | Guide | Source |
|---|---|---|---|---|---|
| E02 | Brake (EBE2, EBE4) | Check the brake levers and calipers work and return properly | Gotrax's fix is adjusting the calipers so they work properly | Gotrax error codes | Gotrax troubleshooting guide |
| E03 | Pedal-assist sensor fault | Change the assist setting or gear | It stays after that: contact Gotrax | Gotrax error codes | Gotrax troubleshooting guide |
| E06, E07, E09 | Low cell voltage / motor fault / controller fault | Switch off and contact Gotrax first | Gotrax treats each as a part replacement: battery, motor, controller | Gotrax error codes | Gotrax troubleshooting guide |
| E08 | Gotrax labels it a handlebar failure without naming the part | Ask Gotrax which part before buying anything | Gotrax's fix is new handlebars | Gotrax error codes | Gotrax troubleshooting guide |
| E10, E11, E12 | Communication receive / send / battery-management communication | Nothing to check: Gotrax calls these internal | Gotrax asks for the bike back for repair | Gotrax error codes | Gotrax troubleshooting guide |
| E13 | Headlight fault | Check the headlight and its connection | Gotrax's fix is a new headlight | Gotrax error codes | Gotrax troubleshooting guide |
| ERROR 21–25, 30 | F3 V2: motor current, throttle, motor phase, motor Hall, brake, display communication | Check the connection cable for that part first; for 25, also check both brake levers have returned | Gotrax replaces the part only if the cable is fine (motor for 21, 23 and 24; throttle, brake levers, display for 22, 25 and 30) | Gotrax error codes | Gotrax F3 V2 manual |
| 0x21, 0x25 | Mustang: motor Hall signal line / motor phase wire | Switch off and reseat the motor connector | The connector is sound and the code returns: contact Gotrax | Gotrax error codes | Gotrax Mustang manual |
| 0x22, 0x23 | Mustang: throttle / controller fault | Reseat the throttle plug; controller faults go to Gotrax support | The throttle plug is sound and the throttle fails the voltage test | Gotrax error codes | Gotrax Mustang manual |
| 0x24 | Mustang: under-voltage protection (not a Hall code on this bike) | Charge the battery | It keeps showing on a full charge: a battery question for Gotrax | Gotrax error codes | Gotrax Mustang manual |
| 0x30, 0x31, 0x34 | Mustang: communication / power button stuck / walk-assist button stuck | Reseat the display plug (0x30); check the buttons spring back (0x31, 0x34) | Still there with the plug reseated and the buttons free: contact Gotrax | Gotrax error codes | Gotrax Mustang manual |
Bafang
Bafang's codes come from two kinds of manual: the DP C244/C245 and DP E162/E163 dealer manuals for its CAN-bus displays, and the C961, BBSHD, 500C and 860C manuals for kit and color displays. They share most numbers but not all. The DP C244 manual says to restart the system first when a code appears, and the last column gives each manual's own fix order.
| Code | What it means (our words) | Check first | When it is likely the part | Guide | Source |
|---|---|---|---|---|---|
| 04 / 05 | Throttle: one of the pair means the throttle is not back at rest, the other a throttle fault; which is which depends on the display model | Let the throttle spring back; reseat its plug and check the cable | DP C244 dealer manual: a new throttle after the plug and cable check out; the DP E162 manual (code 05) then adds the controller, or the drive unit on mid-drives | Throttle test with a multimeter | Bafang DP C244 dealer manual; Bafang DP E162 dealer manual; Bafang C961 manual; 500C manual |
| 06 | Low-voltage protection (C961, BBSHD kits and 500C; not in the CAN dealer table) | Charge, then measure pack voltage at the discharge port | The pack will not hold its charge: a battery question for the bike's maker | Bafang error codes | Bafang C961 manual; Bafang BBSHD dealer manual; 500C manual |
| 07 | Over-voltage protection | Check the battery's rated voltage matches the system; remove and refit the battery | DP C244 dealer manual: a controller software update, then the battery. DP E162: confirm the battery's rated voltage matches, then the battery, then the controller (drive unit on mid-drives) | Bafang error codes | Bafang DP C244 dealer manual; Bafang DP E162 dealer manual |
| 08 | Hall sensor signal fault inside the motor | Check every motor connector for water and corrosion | DP C244: the motor connectors, then a new motor. DP E162: on hub motors, the motor cable, then the motor, then the controller; on mid-drives, the drive unit | How to test Hall sensors | Bafang DP C244 dealer manual; Bafang DP E162 dealer manual |
| 09 | Motor phase wire fault | Inspect the motor cable and any extension for a pinched or crushed section | DP C244 goes straight to a new motor. DP E162: on hub motors, the motor cable, then the motor, then the controller; on mid-drives, the drive unit | Bafang error codes | Bafang DP C244 dealer manual; Bafang DP E162 dealer manual; Bafang BBSHD dealer manual |
| 10 | Over-temperature: the motor on CAN systems and BBSHD kits, the controller on C961, 500C and 860C displays | Stop and let it cool | DP C244: a new motor only if it keeps happening after cooling. DP E162: after a long ride just let it cool; with no ride or a short ride, the motor then the controller on hub motors, or the drive unit on mid-drives | Bafang error codes | Bafang DP C244 dealer manual; Bafang DP E162 dealer manual; Bafang C961 manual; 500C manual; 860C manual; Bafang BBSHD dealer manual |
| 11 | Temperature sensor fault: the motor's sensor on CAN systems, the controller's on C961 and BBSHD | Restart after cooling | A part-level fault: the sensor sits inside the motor (CAN) or controller (C961, BBSHD) | Bafang error codes | Bafang DP C244 dealer manual; Bafang C961 manual; Bafang BBSHD dealer manual |
| 12 | Current sensor fault in the controller | Restart and note whether it returns | Bafang's dealer manual: a new controller | Bafang error codes | Bafang DP C244 dealer manual; Bafang C961 manual |
| 21 | Speed sensor fault | Check the spoke magnet still lines up with the sensor; the right gap depends on the sensor model; check the sensor plug | DP C244: a controller software update, then the speed sensor, then the controller. DP E162: on hub motors, the motor cable, then the motor, then the controller; on mid-drives, the magnet gap and sensor cable, then the speed sensor, then the drive unit | Bafang error codes | Bafang DP C244 dealer manual; Bafang DP E162 dealer manual |
| 22 | Battery-management (BMS) communication fault (kit and color displays) | Refit the battery and check its contacts | It stays: ask the bike's maker (Bafang's BBSHD manual points to the battery) | Bafang error codes | Bafang C961 manual; 500C manual; Bafang BBSHD dealer manual |
| 25 | Torque sensor signal fault (torque-sensor bikes) | Check the sensor connection | Reading live values needs Bafang's service tool; after a software update, Bafang's next step is the torque sensor | Bafang error codes | Bafang DP C244 dealer manual; 860C manual |
| 26 | Torque sensor fault; most Bafang tables pin it to the sensor's rotation (speed) signal, not road speed | Inspect the sensor plug and the cable where it leaves the bottom bracket | DP C244: display, then a software update, then the torque sensor. DP E162: on hub motors, the torque sensor cable, then the sensor, then the controller; on mid-drives, the drive unit | Bafang error 26 | Bafang DP C244 dealer manual; 860C manual; Bafang DP E162 dealer manual |
| 30 | Display-to-controller communication fault | Reseat the display and data-bus plugs, check the cable at the head tube, and confirm a replacement display matches the protocol | DP C244: display, then the data-bus cable, then a software update, then the controller. DP E162: after the cable check, the controller (drive unit on mid-drives) if the display switches itself off about 20 seconds after showing the code, otherwise the display | Why a new display may not work | Bafang DP C244 dealer manual; Bafang DP E162 dealer manual |
| 42 | Battery voltage too low (CAN systems) | Charge fully and retest | It stays after a full charge: both CAN dealer manuals point to the battery | Bafang error codes | Bafang DP C244 dealer manual; Bafang DP E162 dealer manual |
APT color displays (750C, 850C)
Some 750C and 850C manuals use the short 01–07 table below. Another 750C manual uses a longer 04–30 table like Bafang's. Check which manual version came with your display before reading a code: the same number means different things in the two tables.
| Code | What it means (our words) | Check first | When it is likely the part | Guide | Source |
|---|---|---|---|---|---|
| 01 | Communication fault | Check the communication cable and connector for a bent pin or pinch | The cable is sound: see the controller-or-display guide | APT display error codes | 850C manual (short table); 750C manual (short table) |
| 02 | Controller protection; the manual points to the motor phase wires | Inspect the thick motor leads and their connector | The leads are sound and it returns: test the motor and controller | APT display error codes | 850C manual (short table); 750C manual (short table) |
| 03 | Three-phase power fault | Same phase connector: unplug, look for a low pin or water residue, reseat | The connector is sound and it returns: test the motor and controller | APT display error codes | 850C manual (short table); 750C manual (short table) |
| 04 | Battery low (not a throttle code on this table) | Charge the battery | It keeps showing on a full charge: a battery question for the bike's maker | APT display error codes | 850C manual (short table); 750C manual (short table) |
| 05 | Brake fault | Unplug the brake sensors one at a time | Narrowed to one side's brake circuit: check that lever returns fully, its adjustment and its wiring before replacing the sensor or lever | The brake sensor guide | 850C manual (short table); 750C manual (short table) |
| 06 | Throttle fault | Check the throttle returns to rest and its plug is dry | The plug is sound and the throttle fails the voltage test | Throttle test with a multimeter | 850C manual (short table); 750C manual (short table) |
| 07 | Hall fault | Start at the motor connector, not the motor | A Hall signal fails the test in the guide while the connector is known good | How to test Hall sensors | 850C manual (short table); 750C manual (short table) |
| 08–99 | Reserved on the short table: the manual tells you to ask the maker | Check your manual version; if it is the short table, treat the code as unidentified | Unknown until the maker identifies the code | APT display error codes | 850C manual (short table); 750C manual (short table); 750C instruction (long table) |
KT (Kunteng) LCD displays
KT's segment displays (KT-LCD3, LCD5 and similar) show the code with an _info suffix and define only five codes; there is no 02 or 07 in the manual. Other KT displays may use a different list, so check the manual that came with yours.
| Code | What it means (our words) | Check first | When it is likely the part | Guide | Source |
|---|---|---|---|---|---|
| 01 | Throttle fault | Check the throttle springs back; reseat its plug and look for water | The plug is dry and sound and the throttle fails the voltage test | KT-LCD error codes | KT-LCD3 manual; KT-LCD5 manual |
| 03 | Motor Hall signal fault | Start at the motor connector | A Hall signal fails the test in the guide while the connector is known good | How to test Hall sensors | KT-LCD3 manual; KT-LCD5 manual |
| 04 | Torque sensor signal fault (torque-sensor bikes only) | Check the sensor's alignment and connector | The connector and alignment are right and it returns: test the torque sensor before buying | KT-LCD error codes | KT-LCD3 manual; KT-LCD5 manual |
| 05 | Axle speed sensor fault (torque-sensor versions only) | Find which speed sensor your bike uses and check its plug and cable | The plug and cable are sound and it returns: test the sensor before buying | KT-LCD error codes | KT-LCD3 manual; KT-LCD5 manual |
| 06 | Short circuit in the motor or controller | Disconnect the battery and stop powering the bike up; inspect the phase wires for damage | No visible damage to the wires: the motor and controller need testing before the bike is powered again | KT-LCD error codes | KT-LCD3 manual; KT-LCD5 manual |
SW900 and similar displays (0–13)
The SW900 counts from 0, and four of its numbers are status messages, not faults. Sciwil's S830 manual uses the same fault numbers (it has no 11, and its 01 is reserved). The same numbers also appear as E003–E011 on Lectric and E02–E13 on Gotrax's EBE2 and EBE4, with matching meanings where they overlap, except that Gotrax words E08 as a handlebar failure.
| Code | What it means (our words) | Check first | When it is likely the part | Guide | Source |
|---|---|---|---|---|---|
| 0, 1, 4, 5 | Not faults on the SW900: normal (0), setting saved (1), walk mode (4), cruise (5); the S830 lists 01 as reserved | Nothing to fix; leave the mode and it clears | Not a fault | SW900 error codes | King-Meter SW900 instructions; Sciwil S830 manual |
| 2 | Brake signal | Unplug the brake sensors one at a time to find a stuck side | Narrowed to one side's brake circuit: check that lever returns fully, its adjustment and its wiring before replacing the sensor or lever | The brake sensor guide | King-Meter SW900 instructions; Sciwil S830 manual |
| 3 | Listed as a pedal-assist problem (a riding mark), but both manuals mark it as not implemented, so it is not a confirmed fault on these displays | No check we can confirm for this code. If a 3 shows, identify your display's exact model and firmware and read its own manual, and judge by the symptom rather than the number | Do not buy a part because of this number. If pedal assist really fails, work through the cadence sensor guide | Cadence sensor troubleshooting | King-Meter SW900 instructions; Sciwil S830 manual |
| 6 | Battery voltage low | Charge it | It keeps showing on a full charge: a battery question for the bike's maker | SW900 error codes | King-Meter SW900 instructions; Sciwil S830 manual |
| 7 | Motor fault | Start at the motor connector | The connector is sound and it returns: test the motor before buying | How to test Hall sensors | King-Meter SW900 instructions; Sciwil S830 manual |
| 8 | Throttle fault | Reseat the throttle plug and check its cable | The plug is sound and the throttle fails the voltage test | Throttle test with a multimeter | King-Meter SW900 instructions; Sciwil S830 manual |
| 9 | Controller fault | Try a full hard reset with the battery out (our guide) | It survives the reset with every plug checked: test the controller before buying | Our hard-reset guide | King-Meter SW900 instructions; Sciwil S830 manual |
| 10 / 11 | Communication: the display is not receiving (10) or not sending (11) | Unplug and inspect the communication cable and both connectors | The cable is sound: see the controller-or-display guide | SW900 error codes | King-Meter SW900 instructions; Lectric XP 3.0 manual |
| 12 | Battery-management (BMS) communication | Check the communication line and its connector before blaming the pack | The line is sound: ask the bike's maker | SW900 error codes | King-Meter SW900 instructions; Sciwil S830 manual |
| 13 | Headlight circuit fault | Disconnect the headlight and see if the code clears | It clears with the light unplugged: the fault is in the headlight or its wiring | SW900 error codes | King-Meter SW900 instructions; Sciwil S830 manual |
Same number, different meaning
These numbers mean different things depending on the system. If your code is one of them, confirm the display before you order a part. Each entry comes from the tables above or from the manuals listed under Sources.
| Number | What it means on each system |
|---|---|
| 04 | Bafang: throttle not at rest or throttle fault · APT 750C/850C short table: battery low · KT: torque sensor · SW900: walk mode (not a fault) · Ride1Up Revv1: throttle not at rest |
| 06 | Bafang C961, BBSHD and 500C, SW900: low voltage · KT: motor or controller short circuit · APT short table: throttle · Rad color displays: battery undervoltage |
| 07 | Bafang: over-voltage · APT short table: Hall fault · SW900: motor fault · KT: not defined |
| 21 | Shared family, Rad, Aventon, Velotric, Jasion, Gotrax F3 V2: current fault · Bafang and Ride1Up Revv1: speed sensor · Velotric E21: low supply to the display · Gotrax Mustang 0x21: motor Hall line |
| 24 | Shared family: motor Hall · Bafang 500C and 860C and Ride1Up Revv1: headlight sensor · Gotrax Mustang 0x24: under-voltage |
| 25 | Shared family: brake · Bafang: torque signal · Gotrax Mustang 0x25: motor phase wire |
| 30 | Communication fault on the shared family, Rad, Aventon, Velotric, Bafang, Jasion, Gotrax F3 V2 and Ride1Up · KT has no 30 · SW900 uses 10 and 11 · the APT short table uses 01 |
| 34 | Rad: walk-mode release fault (RadRover manual) or a stuck button (color displays) · Gotrax Mustang 0x34: walk-assist button stuck |
When the code really points to a part
If the free checks do not clear the code, measure before you buy. The minimal-system method narrows a fault down by adding parts back one at a time, and the controller-or-display decision guide helps you decide between replacing the controller, the display or both. Before you buy a new display, confirm with the bike's or display's maker that it is compatible with your controller; our protocol guide covers what to check.
For a symptom without a code, start from e-bike repair online or e-bike repair DIY. When you are ready to compare parts, browse e-bike spare parts.
How we built this table
- Each meaning is rewritten in our own words from the maker's manual or help pages, or from the independent guides listed for that row, not copied from them.
- We state a meaning only when the maker's own manual or help pages give it, or at least two independent sources agree. Where they disagree (Aventon E41, E42 and E44, for example), the row says so instead of picking one. The Source column links the pages behind each row.
- What we add is the check-first step, when a part is the likely answer, and a link to the step-by-step guide on this site. Where a maker's manual or help page gives its own fix order, the row names that source and follows its order; elsewhere the advice is ours.
- Rad's color-display page is no longer online, so we link the archived copy dated November 9, 2024. Manuals change between versions; if the manual that came with your bike says something different, follow it.
Sources
Shared 21–30 codes: King-Meter E5227 user guide (5S protocol); King-Meter KM6S-LCD user guide (hosted copy); King-Meter KM5S-LCD user guide (hosted copy); APT 800S-UART-5S display specification (hosted copy).
Rad Power Bikes: RadRover owner's manual v4 (hosted copy); Rad Power Bikes help page on color-display codes (archived copy dated November 9, 2024; the live page now returns not found).
Aventon: Aventon Pace 500 owner's manual (2018); Aventon Aventure user manual (hosted copy); Electric Kicks help center, Aventon error code index; Electric Kicks help center, Aventon E21; Electric Kicks help center, Aventon E26; Electric Kicks help center, Aventon E27; Electric Kicks help center, Aventon E28; Electric Kicks help center, Aventon E29; Electric Kicks help center, Aventon E30; Electric Kicks help center, Aventon E31; Electric Kicks help center, Aventon E41; Electric Kicks help center, Aventon E42; Electric Kicks help center, Aventon E44; Upway, Aventon e-bike error code guide (part 2).
Lectric: Lectric XP4 user manual v1.3; Lectric XP 3.0 user manual v1.5.
Heybike: Heybike Mars 3.0 user manual V3; Heybike Ranger 3.0 Pro user manual V3.
Velotric: Velotric Help Center, "Velotric Error Codes Troubleshooting Guide" (E-code models); Velotric Help Center, "Velotric Error Codes Troubleshooting Guide" (21–30 models); Velotric Go 1 and Packer 1 owner's manual.
Ride1Up: Ride1Up support, Error 21; Ride1Up support, Error 23 and Error 24; Ride1Up support, Error 25; Ride1Up support, Error 30; Ride1Up support, brake sensor issues; Ride1Up, Revv1 display error codes explained.
Jasion: Jasion EB7 user manual V3; Jasion X-Hunter user manual V2.
Gotrax: Gotrax Electric Bike Troubleshooting Guide; Gotrax F3 V2 user manual; Gotrax Mustang user manual.
Bafang: Bafang DP C244/C245 dealer manual; Bafang DP E162/E163 dealer manual; Bafang C961 display manual (hosted copy); Bafang HD drive system (BBSHD) dealer manual (hosted copy); 500C display manual (hosted copy); 860C display manual (hosted copy).
APT 750C / 850C: 750C full-colour display manual (hosted copy, 01–07 table); 850C display manual (hosted copy, 01–07 table); 750C instruction (hosted copy, long 04–30 table).
KT (Kunteng): KT-LCD3 user manual V4.3 (Kunteng); KT-LCD5 user manual V3.2 (Kunteng).
SW900 and similar: King-Meter LCD-SW900 instructions (forum-hosted copy); Sciwil S830 Protocol 2 user manual V6.03.
RideRow is an independent parts retailer and is not affiliated with, endorsed by, or sponsored by any brand named on this page. Brand, display and model names are trademarks of their respective owners and are used only to identify the systems each table covers.