Yamaha e-bike error codes: 12, 13, 31 to 39, 61 to 79
Last checked Nov 4, 2026 · By EbikePost editors
Yamaha's e-bike owner's manual has a code table in its Troubleshooting section. When the system faults, the display alternates between the riding screen and "Er," and the function display names the error. Yamaha's table lists 12, 13, 31 to 39, 61 to 68, 71, 73, 74, 79 and a speed sensor fault. Yamaha's own first instruction is to turn the power off and on again, and if that doesn't solve it, have a dealer inspect the bike as soon as possible.
What we could and couldn't confirm
The table below comes from Yamaha Motor Europe's owner's manual X3W-F819D-E0 (English translation of an Italian original), the document Yamaha publishes in its European owner's manual library. The manual doesn't name the drive unit in the text we could read, so we can't tell you which drive units and displays it covers. Yamaha supplies drive systems to many bike brands, and manuals are published per bike and system. Check the manual for your exact bike on Yamaha's owner's manual page, or ask your bike brand.
We found no Yamaha-published code table for older PW-series displays that we could verify, so codes you may have seen quoted elsewhere, such as 15, 23 or other numbers, aren't in this table. Yamaha's table has no code 15 or 23. For those, go to your own manual or a Yamaha dealer.
How Yamaha shows a fault
Yamaha's manual says the e-Bike Systems have a diagnosis mode. If a malfunction occurs, "the main riding display and 'Er' will be shown alternately, while an error description will inform you of the type of error in the function display." The Troubleshooting page says the problem "occurs in the e-Bike Systems" and to "turn off the power and then turn it on again." If the problem can't be solved, the manual says to have your bicycle inspected by a dealer as soon as possible.
The manual also says the system collects error codes, which are read by attaching a special Yamaha diagnostic tool, and that this is done "only when maintenance checks or service procedures are performed." So a dealer can read more than you can see on the display.
Yamaha error codes at a glance
Yamaha's table has columns for the faulty device, fault details, restoration condition and action. The actions are mostly part replacements. We show Yamaha's meaning, then split what an owner can do from what belongs to a dealer.
| Code | Fault device and what Yamaha says | Restoration (per Yamaha) | Safe checks you can do | When to see a dealer |
|---|---|---|---|---|
| 12 | Display unit: communications to the display stopped | Can return to normal immediately if no error is detected | Switch off. Take the display off its mount and reseat it, as Yamaha's display troubleshooting says | If it returns |
| 13 | Drive unit to display: data failure to display unit | Not stated for this code | Confirm the display is the right one for the drive unit (Yamaha's action: "make sure the combination ... are correct") | Always, if you've changed a display |
| 31 to 37 | Torque sensor: no signal, disconnection, short circuit, wiring failure or abnormal voltage | Can return to normal when the power is cycled; if the same error is detected several times it can't, even when cycled | Power cycle | If it returns. Yamaha's actions involve replacing sensor, controller or drive unit |
| 38, 39 | Crank sensor: abnormal sensor voltage while the motor isn't operating | Can return to normal when power is cycled | Power cycle | If it returns |
| 61 | Controller: overcurrent applied to a motor phase | Can return to normal when power is cycled | Power cycle | If it returns |
| 62 | Motor: abnormal current applied to a motor phase | Can't return to normal even when power is cycled | Don't ride | Always |
| 63, 66 | Controller: data reading failure; external memory (EEPROM) error | Can return to normal when power is cycled | Power cycle | If it returns |
| 64 | Controller: circuit board temperature too low (-20 C) or too high (125 C), or board sensor nearly detached | Can return to normal when power is cycled; can't if detected several times | Let the bike reach normal temperature, then power cycle | If it returns |
| 67 | Motor: lead wires disconnected | Can return to normal when power is cycled | Power cycle | Always |
| 68 | Encoder: disconnected or short-circuited lead | Can return to normal when power is cycled | Power cycle | Always |
| 71 | Battery: can't receive data from the battery correctly | Can return to normal when power is cycled | Yamaha's first action is to check the connection between battery pack and bike; remove and reseat the battery as your manual describes | If it returns |
| 73 | Battery: detected battery voltage too high (45 V) | Can return to normal when power is cycled | Power cycle | Always |
| 74 | Battery: internal system failure; battery capacity indicator may flash abnormally | Not stated | Stop using the battery | Always, and see the battery service manual per Yamaha |
| 79 | DC/DC converter: abnormal DC current | Can return to normal when power is cycled | Power cycle | If it returns |
| Speed sensor (shown as a dash in Yamaha's table) | Speed sensor disconnected | Can return to normal immediately | Check the speed sensor lead connector you can see, and the gap between sensor and wheel magnet | If it returns |
Yamaha's troubleshooting table also says to check the speed sensor position on the rear wheel spokes, and that the distance from the speed sensor must be between 5 mm and 17 mm.
Steps to try, in order
- Stop and read the display. Note the number shown after "Er" and any message.
- Switch the power off, then on. This is Yamaha's own first step, and its table says many codes "can return to normal" when the power is cycled.
- Check the battery is seated correctly and the contacts are clean and dry. Yamaha's troubleshooting says to remove the battery pack, reinsert it, and make sure it's positioned correctly, and to clean contacts with a soft, dry cloth.
- Check the display is mounted properly on its support, and the display and support contacts are clean.
- Let a hot or cold bike settle. Yamaha's battery troubleshooting says to wait until an overheated battery has cooled.
- If the code returns, stop. The rest of Yamaha's actions are replacements.
Yamaha's own actions for most codes are to replace a display, wire lead, sensor, controller, drive unit, motor or battery. None of those is an owner job. Don't open or repair the battery, motor, controller or wiring, and don't try to reset a code with software or a tool. Take the bike to a Yamaha-system dealer or your bike brand's service shop. Stop using the battery and the charger and get it checked if the charger "emits abnormal noises, foul odors or smoke," which Yamaha's manual says to treat as unplug and stop at once.
Charging: what Yamaha's manual says
Yamaha's troubleshooting says charging may not start if the battery is hot or cold, and that the charging range is 15 to 25 C. It also says it's normal for the charger to get "somewhat warm." If both side battery capacity indicator lamps flash at once, Yamaha says the battery's protection feature has activated and the pack should be replaced at a dealer. For wider checks see our e-bike battery won't charge guide.
FAQ
What does Yamaha e-bike error 12 mean? In the Yamaha manual above, 12 means communications to the display unit stopped. Yamaha's action list starts with checking the display unit connector, and the rest are replacements. For an owner, reseating the display on its mount is the safe step.
What does Yamaha error 71 mean? The battery data can't be received correctly. Yamaha's first action is to check the connection between the battery pack and the bike.
Is there a Yamaha error 15 or 23? Not in the Yamaha manual we read. Don't rely on a forum for a meaning. Check your own manual or ask a dealer to read the code.
Is there a Yamaha error code for the battery? Yes, 71, 73 and 74 are battery codes in Yamaha's table.
Other e-bike makers
Not on a Yamaha system? See the e-bike error codes hub, or our Bosch and Shimano STEPS pages.
Written from Yamaha's own manual. EbikePost editors have not ridden or repaired these bikes. Check your own bike's manual, because codes can differ between systems and model years.
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