Odometer resetting and incorrect speed readings on the dashboard of an electric vehicle

An odometer that keeps resetting is most often caused by a problem with the power supply to the dashboard (for example a faulty converter or a chafed power cable) or by a faulty dashboard unit. An inflated or incorrect speed reading usually appears after a tyre change, after a collision (damaged sensor, lost calibration) or when the wheel size is set incorrectly in the dashboard. The first step is to establish exactly when the fault occurs and to compare the readings with GPS.

This advice is based on solutions to specific, anonymised cases handled by Amperi Service. Every case can be different – the steps described do not replace a professional service diagnosis.

Symptoms

The total or trip odometer resets or reverts to a lower value.
The display resets while riding, after a knock, or after switching the ignition off.
The speed shown on the dashboard is clearly higher than the actual speed, for example after a rear tyre change.
Speed readings are unstable or incorrect after a collision or fall.
Other faults appear alongside: an indicator not working, weakened braking, no response from a lever switch, a blowing fuse.
The vehicle seems slower than its declared top speed, especially in riding modes with limited power or at a lower battery charge level.

Possible causes

A faulty converter powering the on-board components, including the dashboard – in one case the odometer resetting stopped after the converter was replaced.
A faulty dashboard or display unit that needs replacing or recalibrating.
A damaged speed sensor after a collision or fall.
A chafed power cable between the fuse and the battery, causing resets and a blowing fuse (risk of a short circuit and fire).
Signs of unprofessional work on the controller and motor wiring.
A tyre replaced with one other than the manufacturer specifies. The dashboard converts wheel revolutions to speed using a stored wheel circumference: a tyre with a smaller rolling circumference inflates the readings and a larger one deflates them. Lower tyre pressure or an incorrect wheel-size setting in the dashboard can have a similar effect.
Incorrect geometry or a bent wheel after a collision, which affects handling and may occur together with incorrect readings.
Performance differences caused by the riding mode, load and battery charge level (voltage sag reduces performance). The declared top speed differs between models and modes, so check it in your vehicle's manual. The power and speed limits in the riding modes follow type-approval and legal requirements – do not change them yourself or copy settings from another vehicle.

What you can check

Note when the fault occurs: after switching the ignition on, over bumps, when braking, at a low battery level, or after rain. Take a photo of the dashboard showing the current odometer reading to document the scale of the problem.
Compare the speed shown on the dashboard with GPS speed (a phone app in a mount – do not handle the phone while riding) on a flat, safe road at a steady speed. Record several measurements, for example at 20, 30 and 45 km/h, within legal limits and the vehicle's capabilities. Write the results down after you stop. Do not run this test on a stand with the wheel in the air – the dashboard will show an inflated speed while GPS shows zero.
If the problem appeared after a tyre change, check the tyre size on the sidewall and compare it with the vehicle manufacturer's recommendations. Also check the tyre pressure.
When assessing top speed, check the riding mode and the battery charge level. Test the vehicle with a charged battery, with no passenger or luggage, in the same conditions.
Check the other symptoms: the indicators, the brake lights, how effective the rear and front brakes are, and the response of the lever switches.
After a collision or fall, inspect the vehicle externally: whether the front wheel is straight, whether the handlebars pull to one side, and whether the mirrors, levers or any externally visible cables are damaged. Do not ride until it has been checked if the vehicle pulls to one side or the brakes are weak.
Do not open the battery or the high-voltage electronics covers, and do not modify the wiring. Do not attempt to interfere with the cables between the fuse, battery, controller and motor yourself. Do not fit a higher-rated fuse, and do not ride if the fuse keeps blowing. Do not change the wheel-size setting or speed limits just to make the dashboard match a single GPS measurement.
Prepare a description of the symptoms, photos of the dashboard, the GPS comparison results and details of any recent work, such as a tyre change, for the diagnosis.

Follow safety rules when working with batteries and electrical equipment. Do not open batteries or high-voltage electronics. Unauthorised modifications to the equipment during the warranty period may void the warranty.

When to contact the service

The vehicle should go to a workshop when the odometer resets repeatedly, the display resets while riding, and the speed readings differ from GPS consistently or erratically. The same applies when the fault appeared after a collision or fall, when a fuse blows (a possible short circuit – stop riding until it has been diagnosed), when other faults appear (brakes, indicators, geometry), and when the tyre has been replaced with one other than recommended. The workshop checks the dashboard power supply, the converter, the speed sensor, the wiring and the display calibration (including a wheel-size setting that matches the manufacturer's specification).

FAQ

Why does the odometer reading reset?

The most common cause is a problem with the power supply to the dashboard, such as a faulty converter or a chafed power cable, or a faulty dashboard unit itself. In one case the problem went away after the converter was replaced, and in another after the dashboard was replaced.

Can a tyre change alter the speed readings?

Yes. The dashboard calculates speed from wheel revolutions and a stored wheel circumference. A tyre with a smaller rolling circumference inflates the readings, and a larger one deflates them. If after a rear tyre change the dashboard shows more than GPS, check the tyre size and pressure, and whether the dashboard calibration matches the wheel size recommended by the manufacturer.

How can I check whether the dashboard is overstating speed?

Compare the reading with GPS speed on a flat road, at a steady speed, with a charged battery, within legal limits. Repeat the measurement several times at different speeds and record the results after you stop. Do not handle your phone while riding. Do not test on a stand with the wheel in the air.

Can the dashboard show an incorrect speed after a collision?

Yes. A collision can damage the speed sensor, throw the display out of calibration, damage cables or change the wheel geometry. In one case after a collision the display needed recalibrating and the sensor was damaged.

Why does the vehicle not reach its declared top speed?

The factors involved are a riding mode with limited power, the battery charge level (voltage sag reduces performance), load and tyre pressure. Also check the declared top speed for your specific model and mode. Do not remove speed or power limits yourself: this may be illegal and contrary to the type-approval, can void the warranty and insurance, and can overload the brakes and tyres.

Can I check the wiring myself if the fuse keeps blowing?

No. The power cables, battery and controller are high-voltage components, and a repeatedly blowing fuse may indicate a short circuit and a fire risk. You can only describe the symptoms and inspect the vehicle externally. Do not fit a higher-rated fuse. The wiring diagnosis is carried out by a workshop.

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Updated: 2026-10-31 · Serwis Amperi · serwis@amperi.eu