Step 1: Record the warning before resetting
Take a photo of the screen showing the complete code or message. Note whether the warning appears at startup, when accelerating, after rain, when the battery is low, or only after a long ride. If the warning clears after power cycling, record that too; a disappearing warning is still useful diagnostic evidence.
Step 2: Identify your display
Look at the display's shape, button layout, startup screen and any model markings. Do not choose a manual only because it says “Shengmilo.” The manufacturer has used different displays across different models and years. The S600 PRO support centre publishes a display manual section; check it against the unit fitted to your bike.
Step 3: Use this symptom-to-check table
| Symptom | Safe first checks | Escalate if… |
|---|---|---|
| Display blank | Battery charge, seating, power button sequence, visible external connections | Battery is charged but display remains dead, or connectors show heat damage |
| Display restarts under load | Record charge level and when the restart occurs; check external battery seating | It repeats under ordinary use or the battery/connector becomes hot |
| Motor error message | Record exact code, switch off, inspect accessible connectors with power off | Message persists, motor grinds, or wiring is damaged |
| Brake-related warning or no assistance | Check that both levers return freely and are not being held on | Brake function is impaired or sensor/wiring needs adjustment |
| Battery/voltage warning | Charge using the supplied compatible charger; record charge indication | Battery voltage appears erratic, pack is hot/swollen, or cut-outs recur |
| Speed/distance seems wrong | Verify display settings against the correct manual; note tyre size setting if user-adjustable | Changing settings would require undocumented access or a password |
Do not guess at undocumented P-settings
Display parameter menus can control wheel-size assumptions, speed limits, assistance behaviour and other system settings. A wrong value may produce inaccurate speed/distance readings or affect operation. Do not copy settings from an unrelated Shengmilo model or a random video. Avoid undocumented passwords and do not change controller current, voltage or safety-related parameters as a diagnostic experiment.
How to send support a useful error report
- Bike model and approximate purchase date.
- Photo of the display and its complete warning.
- Photo of the display label or model marking, if accessible without dismantling.
- Battery label showing voltage and capacity.
- Whether the display stays on, reboots or only removes motor assistance.
- What happened just before the fault: rain, charging, a hill, impact, repair or connector removal.
- Any unusual heat, smell, noise or visible damage.
Do not send only “error on screen.” A clear photo and description of when the error appears are much more useful.
Where to find the correct manuals
Open the manufacturer's S600 PRO User Guide & Support Center. It provides the S600 PRO user manual and a separate display manual. The wider owner's manual library also lists other bike and display manuals. Confirm the version before following a code table.