We all hate when this happens: suddenly, your eBike is not responding and showing an error code. You try to pedal, but it won’t budge, and you are stranded in the middle of nowhere or caught right in the middle of an intersection.

No matter how close or distant from civilization you may be, having an error code pop up and being unable to ride your eBike can be terrifying.

So, whenever this happens, you might wonder: Do I need to find some assistance, or could I try to fix the error codes myself?

Although the majority of system error codes can only be resolved by the bike manufacturer, a few common errors will clear up when you perform a quick restart. So, when your bike depowers, drag it to the side of the road, disconnect/switch off the battery, and try again; you may get lucky.

However, that may not solve the problem, and if the error code keeps popping up, you will have to diagnose the issue. Thankfully, I’ve made this guide for several well-known eBike motor systems such as:

  • Bosch Performance CX
  • Shimano EP8
  • Engwe eBikes

So without further ado, let’s discuss how to fix electric bike error codes.

How to Fix Electric Bike Error Codes on Bosch Performance CX

The Bosch Performance Line CX is one of the best mid-drive units used in many off-road electric bikes because, as the name suggests, it is built for maximum performance.

A few features of the Bosh Performance CX include 85 Nm of torque output, dedicated pedal assistance modes for mountain biking (with better customizability), a very responsive torque sensor, a spoke magnet, and a ton of intelligent features such as walk assistance and eBike locking.

However, with a lot of smart features and onboard computers, there’s often a lot that could go wrong — both in terms of hardware and software.

There are over 50 error codes mentioned in the Bosch manual, and going through each one could be overwhelming. Therefore, I’m only going to talk about a handful of the most common errors and their solutions.

Senior woman preparing her electric bicycle outdoors

Battery-Related Error Codes

Here are some error codes that may pop up when there’s an issue with the eBike battery or the rechargeable battery inside the onboard computer.

200, 430: This pops up when the rechargeable battery of the onboard computer (handlebar mount/HMI unit) is depleted. Try to connect the eBike battery pack (so the computer draws power from the large battery) or recharge the onboard computer/display via MicroUSB. Also happens when there are no lights on the handlebar mount.

423, 530, 606, 610, 655: This error code pops up when the computer cannot detect the eBike battery (Lack of any battery voltage signal). In most cases, the error code disappears when you reinstall the battery. If not, there might be damage to the battery connector pins or the cable connection running from the battery pack to the handlebar mount. (Similar situations include when there are no lights on the power pack, or only two LEDs flashing.)

602, 603, 620, 640: Whenever the BMS (see also how to BMS reset) of the eBike battery detects that individual cells/strings have voltage differences with respect to the others, this error code can pop up. It is mostly when you recharge the battery after not using it for a long period, try recharging a newer battery or use a different compatible charger. (620 602, 603)

Temperature-Related Errors

540, 605: Pops up when the eBike is outside the recommended temperature range (it’s either too freezing or too hot for the battery to power the eBike). The only way to get rid of this error message is to get your bike inside and let it reach a safe temperature. Riding around at extreme temperatures can be detrimental to the battery. (Hence, why the temperature sensors disable the entire system.)

Internal Glitches/Software-Related Errors

Unfortunately, the only way to fix internal errors is by updating the software or restarting the system. So if you see any of these error codes, try performing a quick restart using either the power controls or reconnecting the eBike battery.

426: Occurs during a software timeout, where the software or a certain function has not responded within the allotted time.

440, 500, 511: Internal error of the motor’s drive unit. (Doesn’t communicate with the onboard computer or has run into a glitch)

450, 490, 531: This will pop up when there’s a software glitch in the display/HMI unit. Also, if the battery LEDs work fine but the display doesn’t show anything, it could mean the same thing.

431, 656: Software version mismatch. Pops up when you haven’t updated the firmware to the latest version; fixed by performing a software update by yourself or taking it to a dealer. (431)

Sensor Errors

424: Pops up when the onboard computer cannot get a response from the other components (such as the battery, drive unit, sensors, etc.) If the issue keeps persisting after a quick restart, check the cables and each cable connection/contact for damage.

503, 510: Error with the speed sensor/torque sensor or spoke magnet. Make sure the cable connections are holding up properly, and check back in after a quick restart. If the code keeps popping up, your speed sensors are probably defective.

502: Problem with the illuminators/light system. Check the wiring of these components and try restarting.

550: This comes up when the onboard computer detects an abnormal voltage drop or electrical resistance due to an unknown load. When this happens, disengage the motor, disconnect any mobile phones you might have been charging, restart and check back in.

Fixing Error Codes on the Shimano EP8

Apart from the Bosch Performance Line CX, the Shimano EP8 is the next big kid on the block. This drive system also puts out 85Nm of torque, with a handy controller that offers tons of smart features including a smartphone application that interfaces with the onboard computer.

So let’s talk about some of the most common error codes you can get from a Shimano EP8 system along with what you can do to resolve them.

Battery-Related Error Codes

E021: This error code is displayed when the onboard computer detects a different battery, despite having the proper specifications (such as Voltage and Amp hours). The only solution is to replace the battery with the original one or reconnect it (if it is the original battery pack) and try again.

E022: Almost the same issue, but here, the specs do not match at all. (Requires the same solution as above).

Temperature Errors

W100, W010: This error code will appear when the motor is overheating. Luckily, you can still ride the ebike using your pedal power. The motor will be completely idle until it reaches a safe temperature. So either take a break and let the bike cool off, away from direct sunlight, or keep pushing (by yourself) without any pedal assist.

W20: Battery temperature is beyond the safe limits. When this happens, the bike will lock up, and the voltage protection circuit will disconnect power to all the other components until it reaches a safe temperature. To resolve this, take your battery and eBike inside, away from direct sunlight or the freezing outdoors.

Sensor/Communication Error Codes

E20: The onboard computer cannot get a signal from the battery or motor cable due to a communication error. Whenever this happens, try restarting or reconnecting the battery. Also, you can try unplugging the wires running from the battery to the motor and check for any defects in the cable connections.

E012, W013, W103, W106: These codes will show up whenever the torque sensor fails to initialize. Most of the time, these errors disappear when you restart the system while keeping the pedals free. However, if that doesn’t work, you can try going for a short ride (while the error code disappears), readjusting the chain tension, or reversing the crank a couple of revolutions and restarting the system. Unfortunately, if all of the above doesn’t work, you’ve got a defective sensor or cable connection.

W012: The computer comes up with this error code when it detects that the crank was installed at the wrong angle or orientation. Reconnect the crank, adjust it properly and see if the code clears up from the screen.

W101, W011, E014: When the onboard computer can’t detect the speed sensor, this error code will appear. Fortunately, you would still be able to ride the eBike, but the amount of pedal assist will be limited since the system has no way of recognizing the actual speed of the eBike. To resolve this issue, make sure the wires connecting the speed sensor (in the rear wheel) are not damaged, and the distance between the spoke magnet and the speed sensor (on the chainstay) is not too high. (It should be 3-17mm apart.)

Internal Errors

E10, E011: Occurs during an internal system error or timeout. It easily goes away with a quick restart or diagnosing via E-TUBE Project.

E033: Caused due to a firmware version mismatch. Although you could ride the eBike, the motor cable will be disconnected, with no pedal assist. It can be fixed by connecting to E-Tube Project and updating the firmware.

E043: Pops up to indicate corrupted firmware. It is due to bugs or issues while updating. To resolve this error code, you must restore the firmware using E-Tube.

Fixing Error Codes on Engwe Smart Ebikes

Let’s go through some of the common errors found in Engwe eBikes.

Luckily, in most Engwe eBikes, the error codes are primarily hardware-based; hence, you will be able to identify the issue and resolve it without having to take it back to the bike shop. (Provided you have the proper tools and a basic understanding of electronics.)

021: If the display pops up with this error, it’s due to the voltage protection circuits detecting a difference in the voltage levels or current draws in the system. As long as there are no short circuits (smoke, burnt smell, or overheating), you can resolve this by checking each connector, contact, or wire for damages and making sure they are properly installed.

022: This error shows up due to an issue with the throttle. First, see if the throttle cable and controller cables are properly connected and don’t have any burnt-out wires or unusual swelling. After that, check to see if the twist-throttle is working properly. Lastly, check the connections between the controller and throttle cable.

023: This error indicates whenever there is a phase loss in the motor. I.e., one of the three cables powering the motor is not conducting electricity. To resolve this, you can check the motor cables (running from the controller to the motor) for damages or loose connections.

024: Pops up when the display cannot recognize the motor hall sensor (sensor that regulates the motor speed). To resolve this, you will have to open the wiring harness near the controller and check the motor hall cables

025: Notifies an error in the braking system. To determine where exactly it is defective, you can check for damage in the braking handles or the two controller cables that run up to the brakes. Try disconnecting the brake connectors (two black connectors that look alike) and checking for any damage in the cables or contacts.

030: Indicates a communication error between the display and the controller. To fix this, make sure the cable running up to the display is not broken or loose and have the arrows pointing towards each other. Also, check the display cable connections near the controller, and be careful not to mistake it for the motor hall cable connector. (Both look like the same five-wire connector terminal.)

The display reads 0 km/h: If the speedometer (in the display) is not showing the speed accurately, it might be an issue with the speed sensor or cables, so make sure to check them for any loose connections. Unfortunately, if the cable seems fine but, the sensor does not respond, you might have to replace the speed sensor. (Still, you will be able to drive around as long as you are vigilant.)


Error codes can be frustrating, especially if you don’t know what you are doing. Thankfully, most common errors can be easily fixed with a quick restart or reconnecting the faulty components.

That said, if you get caught in the middle of the road with a software version mismatch error or broken sensor, you might have to pedal back with no support or diagnostics tools to determine the cause of the internal faults. So make sure you update the firmware, top up the batteries and perform a test run before loading up your eBike on the back of your car and heading out into the trails.

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