Error Code Fixes

Battery Not Charging — What to Check First

Work from the wall socket forward: outlet, charger, charge port, pack. Stop when you find the break.

Applies to: D-series and eBikes

CEMOTO Battery Not Charging? What Would You Check First? — if the player does not load, open the video on YouTube.

Check in this order

Work from the wall outward. Each step rules out one link in the chain.

  1. The wall socket. Test it with something else. Obvious, and regularly the answer.
  2. The charger. Does its indicator light come on? Feel whether it warms up. A charger that stays completely cold is a suspect. Confirm the price and voltage on Spare Parts before ordering.
  3. The charge port on the bike. Look for bent pins, corrosion, debris or water ingress. Reseat the plug firmly and check it is fully home.
  4. The charge fuse. Many packs have an inline fuse on the charge circuit. Check it before condemning anything.
  5. The pack's own connector. Reseat the main battery connector and look for heat discoloration — a high-resistance connection prevents charge current reaching the cells.
  6. Try a slow charge and watch. If the pack is deeply discharged, some chargers will not start a normal charge cycle.
  7. Temperature. Charging a very cold pack can be blocked by the BMS. Let it come to room temperature before retrying.
  8. Only then suspect the pack. See Battery Care & Charging.

⚠ Never use a charger that is not rated for your pack's voltage. A 72V charger on a 48V pack will damage it. Confirm voltage before ordering a replacement.

Decision guide

Finding Action
Socket dead Use another outlet
Charger cold and dark Replace the charger — confirm voltage first
Charge port damaged or wet Clean and dry; replace if pins are bent
Charge fuse blown Replace the fuse and investigate why it blew
Pack cold Allow it to reach room temperature
Everything checks out Contact Support before replacing the pack

Brake Error E02 — Check These Before Replacing Parts

E02 is a signal fault, not a brake fault. The lever not returning fully is the usual cause — and it costs nothing to fix.

Applies to: D-series · Error code: E02

CEMOTO E02 ERROR? Check THESE Before Replacing Parts! — if the player does not load, open the video on YouTube.

What E02 means

E02 = Brake Error. The controller monitors the brake circuit and raises E02 when it sees a signal state it does not expect.

The brake circuit does two jobs: operates the brake, and cuts motor power when the lever is applied (a safety interlock). E02 relates to the electrical signal, not the hydraulic braking force. A bike can have working brakes and still show E02.

⚠ Do not dismiss it as "just electrical". If the lever does not cut motor power, the interlock is not protecting you.

E02 is not a diagnosis of worn pads, low fluid, a warped disc or air in the line — those cause poor braking, not E02. See Brakes.

Check in this order

  1. Does the lever return fully? The most common cause by far. Squeeze and release slowly. Any gap means the switch may be held on. Check for grit in the pivot, a bent lever, or a grip/handguard fouling it. Clean and lubricate, then retest.
  2. Inspect the brake switch and its connector. Look for backed-out pins, corrosion, heat discoloration or a pinched lead where it leaves the lever. Disconnect and reseat — pull the connector body, not the wire.
  3. Test each lever separately. Squeeze front only, then rear only, and note which one triggers the error. That isolates the fault to one circuit.
  4. Trace the wiring from the levers to the controller. Turn the bars lock to lock while watching for a lead that pulls taut or chafes.
  5. Check the controller's brake input pin and reseat the main connector. If E09 or E10 appear alongside E02, suspect the controller.
  6. Consider conditions. Water in a connector, mud around the lever, ice in the pivot, or a crash can all trigger E02.

Decision guide

Finding Action
Lever does not return fully Clean or lubricate; replace the lever if bent
Connector corroded or loose Clean and reseat; replace if pins are damaged
Lead chafed through Repair or replace the lead
Error only in wet conditions Dry and treat the connectors
Persists with the brake circuit disconnected Suspect the controller — see E09

After the fix

Power cycle, then test the cut-off: with the bike powered, squeeze each lever and confirm the motor stops. If the error returns immediately you have not found the cause — do not ride with a known brake interlock fault.

Low Voltage Error E06 — What to Check First

E06 usually means the pack is flat, the connections are poor, or it is simply cold — not that the battery has failed.

Applies to: D-series · Error code: E06

CEMOTO E06 Error? What Would You Check First? — if the player does not load, open the video on YouTube.

What E06 means

E06 = Low Voltage Protection. The pack voltage has dropped below the protection threshold and the controller has cut power to prevent over-discharge.

That threshold is a protection, not a fault in itself — it is doing its job. The question is why the voltage fell that low.

Check in this order

  1. Charge the pack and retry. If E06 clears and stays clear, the pack was simply flat. Nothing is broken.
  2. Check the charge state properly. Does the charger reach full and stop, or does it terminate early? An early cut-off points at the charger or the pack. See Battery Not Charging.
  3. Inspect the main battery connector and fuse. A high-resistance connection sags under load and reads as low voltage. Reseat the connector and check for heat discoloration.
  4. Consider temperature. Usable capacity drops sharply in the cold — roughly 70 % at 14 °F versus 90–95 % at 70 °F. A pack that is fine in summer can trip E06 on a cold morning. This is normal behavior, not a failure.
  5. Check P15 (undervoltage threshold). If it has been lowered to chase range, restore it. See the P-Setting Guide.
  6. Only then suspect the pack. A pack that trips E06 on a genuine full charge, in mild conditions, with clean connections, is a candidate for replacement.

Decision guide

Finding Action
Clears after charging and stays clear Normal — the pack was discharged
Charger terminates early Test the charger; charge time should match the spec
Connector warm or discolored Reseat or replace the connector
Happens only in cold weather Expected — warm the pack before charging and allow for reduced range
P15 lowered Restore it to specification
Full charge, mild weather, clean connections, still trips Contact Support

Watch out for

Motor Error E07 — Motor & Wiring Troubleshooting

E07 rarely means the motor is dead. Phase connectors and the hall sensor plug are the usual culprits.

Applies to: D-series · Error code: E07

Cemoto E07 Error – Motor & Wiring Troubleshooting Guide — if the player does not load, open the video on YouTube.

What E07 means

E07 = Motor Error. It covers hall sensor faults, phase wiring faults and genuine internal motor faults.

It does not distinguish between them. That is why E07 has a deserved reputation for triggering unnecessary motor replacements.

Check in this order

  1. Inspect the motor's main connector. Unplug it, look for backed-out pins, corrosion or heat discoloration, and reseat it firmly.
  2. Check the three phase wires. They carry heavy current and are the most stressed connectors on the bike. Look for a chafed or pinched run where the cable passes the swingarm or frame edge.
  3. Check the hall sensor plug. This is the small multi-pin connector at the motor. A single bent or backed-out pin here produces E07 with a perfectly healthy motor.
  4. Wiggle test with the bike powered: flex the motor cable gently. If the error appears or disappears, the cable or connector is faulty.
  5. Confirm the wheel turns freely with the power off. A dragging brake or a seized bearing can present as a motor fault.
  6. Check for E09 alongside E07. If both appear, the problem may be at the controller rather than the motor.
  7. Only then suspect the motor itself. See Motor Removal and Motor Installation.

Decision guide

Finding Action
Connector loose, corroded or discolored Clean and reseat — no cost
Damaged cable section Repair or replace the cable
Bent hall sensor pin Straighten or replace the plug
Wiggle test changes the fault Cable or connector fault — no motor replacement needed
Wheel does not turn freely Investigate the brake or bearing first
E07 and E09 together Check the controller — see E09
Everything checks out Contact Support before ordering a motor

⚠ Warranty note. Opening the motor yourself voids the warranty on that part. Removal and refitting for a warranty replacement should follow CEMOTO support's instructions. See Warranty Claims.

Throttle Error E08 — Check the Throttle Before Replacing Parts

A twist grip that does not return is far more common than a failed throttle unit.

Applies to: D-series · Error code: E08

E08 Error — Check the Throttle Before Replacing Parts — if the player does not load, open the video on YouTube.

What E08 means

E08 = Throttle Error. The controller is not seeing the throttle signal it expects — usually because the grip is not returning to the idle position, or because the signal path is broken.

Check in this order

  1. Does the twist grip return to idle on its own? Release it and watch. It should snap back fully. If it stays part-open, the controller reads a permanent throttle input. Check for grit in the housing, a fouled grip, or a bar-end pushing into the grip.
  2. Reseat the throttle connector. Look for backed-out pins, corrosion or a pinched lead where it leaves the grip.
  3. Wiggle test with the bike powered — flex the throttle lead and watch for the error appearing or disappearing.
  4. Check for physical damage to the throttle body — a crash or drop commonly cracks the housing.
  5. Check the wiring run to the controller for chafing at the steering head.
  6. Only then order a throttle. See Spare Parts for the compatible part and current price.

⚠ Safety. A throttle that does not return is a runaway risk. Do not ride the bike until it is fixed. Power down before inspecting.

Decision guide

Finding Action
Grip does not return fully on its own Clean and lubricate the housing; check bar-end clearance
Connector corroded or loose Clean and reseat — no cost
Lead chafed or pinched Repair or replace the lead
Housing cracked Replace the twist throttle
Error persists with the throttle disconnected Suspect the controller — see E09

Controller Error E09 — Check These Before Replacing the Controller

Heat, voltage sag and a shorted phase all present as E09. The controller is the last suspect, not the first.

Applies to: D-series · Error code: E09

E09 Error — Check These Before Replacing the Controller — if the player does not load, open the video on YouTube.

What E09 means

E09 = Controller Error. It indicates a controller-internal failure — or, far more often, a condition upstream that the controller is correctly reporting.

An expensive part to replace by guesswork. Confirm the causes below first.

Check in this order

  1. Let it cool. Sustained hard use in hot conditions causes genuine thermal faults. If the code appears only after a long hard ride and clears when cold, that is the answer.
  2. Check supply voltage. A sagging pack or a high-resistance main connection starves the controller. Charge fully, reseat the battery connector and check the fuse. See Low Voltage E06.
  3. Check the phase wires and the motor circuit. A shorted phase can present as a controller fault. Inspect for chafing and check the resistance between phase wires.
  4. Check every controller connector for corrosion, backed-out pins and heat discoloration.
  5. Check for E07 or E10 alongside E09. Both narrow the fault to the motor circuit or the communications path rather than the controller.
  6. Check the controller's mounting and heat path. A controller with no airflow behind a blocked panel will run hot.
  7. Only then replace the controller. See Spare Parts for the compatible part and current price.

Decision guide

Finding Action
Only after sustained hard use Thermal — allow cooling and check airflow
Pack low or connector hot Charge, reseat, check the fuse — no cost
E07 alongside E09 Focus on the motor circuit — see E07
E10 alongside E09 Focus on the display cable and comms
Phase wire chafed or shorted Repair or replace the cable
All checks pass, code persists Genuine controller failure — confirm with Support first

⚠ Warranty note. The controller carries a 12-month warranty period. Opening it voids the warranty on that part — follow CEMOTO support's instructions. See Warranty.

Front Light Error E13 — Don’t Swap the Headlight Yet

Connectors and water ingress cause E13 far more often than a failed headlight.

Applies to: D-series · Error code: E13

E13 Error? Don't Swap the Headlight Yet — Check This First — if the player does not load, open the video on YouTube.

What E13 means

E13 = Front Light Error. The controller is not seeing the expected state on the headlight circuit — an open circuit, a short, or a signal it does not recognize.

Check in this order

  1. Inspect the headlight connector. Unplug it, look for corrosion (green/white deposit), backed-out pins or heat damage, and reseat firmly. This is the most common cause.
  2. Look for water ingress. If E13 appeared after a wet ride or a wash, dry the connector and treat the contacts — do not replace anything yet.
  3. Wiggle test with the bike powered: flex the headlight lead and watch for the error appearing or disappearing.
  4. Trace the lead from the headlight back to the controller. Check for chafing where it passes the steering head and at the fork.
  5. Test the headlight itself. Does it illuminate at all? A light that works but still raises E13 points at the signal path, not the lamp.
  6. Only then replace the headlight assembly — see Spare Parts for the compatible part and current price.

Also check the tail light and brake light circuit if your model links them to the same feed.

Decision guide

Finding Action
Connector corroded or loose Clean and reseat — no cost
Error only after water exposure Dry and treat the contacts
Wiggle test changes the fault Lead or connector fault
Lamp does not illuminate, wiring sound Replace the headlight assembly
Lamp works, wiring sound, error persists Check the controller and comms

Horn Not Working — Check These Before Replacing Parts

A silent horn is usually the button or a loose connector, not the horn itself.

Applies to: D-series (the D02 Track ships without a horn)

Horn Not Working — Check These Before Replacing Parts — if the player does not load, open the video on YouTube.

Before you start

The D02 Track is supplied in a track configuration without a horn. If your bike has no horn at all, this is not a fault — check your model's specification first. See D02 Track.

Check in this order

  1. Press the button firmly and listen. Confirm you are pressing the horn button and not the mode or indicator button.
  2. Check the button itself. Remove it from the bar and look for corrosion or a stuck contact. This is the most common cause of a silent horn.
  3. Inspect the horn's spade connectors. They vibrate loose on a dirt bike. Push each one fully home and check for corrosion.
  4. Check the mounting. The horn earths through its bracket on many bikes. A loose or freshly painted bracket can break the circuit.
  5. Test the horn directly on a known 12V supply if you have one — this isolates the horn from the wiring in one step.
  6. Trace the feed back to the harness and check for a blown fuse or a chafed lead.

Decision guide

Finding Action
Button stiff, corroded or stuck Clean or replace the switch
Spade connector loose Push home; replace the terminal if corroded
Bracket loose or insulated Restore a clean earth path
Horn works on a direct 12V supply Wiring or switch fault, not the horn
Horn dead on a direct supply Replace the horn

CEMOTO Won’t Turn On — What to Check First

Start with the 0-gear sequence. It is not a fault, and it catches out new owners constantly.

Applies to: D-series and eBikes

CEMOTO Won’t Turn On? What Would You Check First? — if the player does not load, open the video on YouTube.

Check in this order

  1. Is the display showing gear 0? The most common cause. The bike will not drive in gear 0 — press + to select gear 1. The bike is not broken. See the D02 Assembly Guide.
  2. Is the power switch / electric door lock on? Confirm the key or switch is in the running position.
  3. Is the battery charged and seated? Reseat the main connector. See Battery Not Charging if it will not take a charge.
  4. Is the kill switch or side-stand cut-off engaged? Some models will not run with the stand down or a cut-off switch active.
  5. Is the brake lever stuck on? A lever that does not return keeps the brake interlock engaged — see E02.
  6. Check the display cable. A display with no power at all may simply have a loose connector. See Wiring & Connectors.
  7. Check the main fuse.
  8. Check for an error code. Note it and work the matching tutorial — see the error code index.

Decision guide

Finding Action
Display reads gear 0 Press + to select gear 1 — not a fault
Power switch off Turn the electric door lock on
Pack flat Charge it
Kill switch or stand cut-off active Reset it
Brake lever not returning See E02
Completely dead, no display Check the display cable and main fuse