E-Bike Display & Controller Settings Guide: P-Settings, Modes & Hidden Menus
E-Bike Display & Controller Settings Guide: P-Settings, Modes & Hidden Menus
To access the hidden settings menu on most Chinese e-bike displays (S866, M5, C961, King-Meter), hold the + and – buttons simultaneously for 3 seconds while the bike is powered on. The screen will flash or shift to a menu labeled P01 or P. From there, use + to cycle through parameters and – to change a value. This same basic method works across brands, but the exact layout and available options vary.
Entering the Settings Menu by Display Type
Each display brand uses a slightly different button sequence. Below are the most common entry points for widely used e-bike displays.
S866 / S830 / S840
- Entry: Press and hold + and – for 3 seconds.
- Navigation: Press + to move to the next P-number; press – to increase the current value; press M to confirm (if present).
M5 / M6 (SW900 / SW-LCD)
- Entry: Press and hold + and – for 5 seconds.
- Navigation: Use + to toggle parameters, – to adjust value, then hold + again to save and exit.
C961 / C965 (Bafang)
- Entry: Turn on the battery, then press and hold + for 8 seconds. An advanced menu appears after the initial main screen.
- Navigation: Press + to scroll, – to change the value. Some models require a separate jumper wire to enable full parameter access.
King-Meter (KM5S, 850C, 860C)
- Entry: Hold + and – for 3 seconds, then press the power button once.
- Navigation: Use + and – to adjust the parameter; press power to move to the next setting.
Bosch / Shimano (Proprietary Displays)
- Exit: These manufacturer systems do not expose P-parameters through the display. Adjustments require a dealer diagnostic tool (e.g., Bosch DiagnosticTool, Shimano E-Tube) or a third-party app adapter.
Branch: If the menu doesn’t appear after 5 seconds, look at the screen. A padlock icon means the display is locked by the manufacturer – you cannot enter P-settings without a dealer code. If the screen stays normal (no flash, no lock), turn the bike off, remove the battery for 30 seconds, then try again right after powering back on. Some controllers have a boot window of only a few seconds.
P-Setting Reference Table: P01 to P20
The P-number codes control the core behavior of your motor controller. Not all numbers are present on every display; the list below covers the most common entries you’ll encounter.
| Code | Name / Function | Typical Range | Default (Common) | Notes |
|---|---|---|---|---|
| P01 | Backlight brightness | 1–5 | 2 | Higher numbers drain battery faster |
| P02 | Unit of speed | 0 (km/h), 1 (mph) | 0 | Change to 1 for US riders |
| P03 | Voltage class (battery type) | 24V, 36V, 48V, 60V, 72V | Varies | Must match your battery – setting wrong voltage can damage the controller |
| P04 | Sleep timer (minutes) | 0–60 | 5 | 0 = no auto-off |
| P05 | Pedal assist level (0–X) | 0–3, 0–5, 0–9 | 0–5 | Higher count means finer assist granularity |
| P06 | Wheel diameter (inches) | 16–29 | 26 | Directly affects speed reading – see section below |
| P07 | Speed limit (km/h) | 0–99 | 25 (EU legal) | Setting to 99 removes cap on most controllers |
| P08 | Motor phase current limit (A) | 10–50 | 20 | Do not exceed controller rating |
| P09 | Start mode / soft start | 0 (high), 1 (medium), 2 (low) | 1 | Lower number gives jerkier start |
| P10 | Driving mode | 0 (pedal assist only), 1 (throttle only), 2 (both) | 0 | Check local laws for throttle usage |
| P11 | Pedal assist sensor sensitivity | 1–24 | 12 | Lower = more pedal turns per assist cycle |
| P12 | Pedal assist sensor strength (start power) | 1–5 | 2 | Higher = more sudden power delivery |
| P13 | Current sensor calibration (rare) | — | — | Leave at default unless you know the exact procedure |
| P14 | Throttle 5V voltage calibration | — | — | Only adjust with a multimeter |
| P15 | Real-time speed calibration (speedometer accuracy) | 50–200% | 100% | Use to fine-tune speed readout after wheel size change |
| P16 | Odometer reset (hidden) | — | — | Some displays require entering a specific number to clear |
| P17 | Controller temperature protection (°C) | 40–80 | 60 | Lower = earlier cutback on hot days |
| P18 | Motor phase angle (120°/60°) | 0, 1 | 1 | Changing this without reason can burn out the motor |
| P19 | Communication protocol selection (CAN/UART) | 0, 1 | 0 | Only needed if you swap controller brand |
| P20 | Factory reset | 0, 1 | 0 | Changing to 1 resets all P-settings to defaults |
Warning: P03, P08, P13, P14, P18, and P19 can permanently damage components if set incorrectly. Always verify the expected value from your controller’s label before adjusting.
Stop/Esclate Threshold: If you change P03 (voltage) or P08 (current limit) and the bike fails to power on, or the display shows a blinking battery icon, stop riding immediately. Set the value back to the original default shown on the controller sticker. If the bike still won’t start, contact the manufacturer or a qualified e-bike shop – further DIY attempts risk destroying the controller or battery.
Adjusting Speed Limit and Wheel Size
These two settings work together to produce an accurate speed reading – and on some displays, they also determine whether the motor cuts out at a certain speed.
Wheelsize Setting (P06)
- Set the number closest to your actual tire diameter (e.g., 26 for 26-inch tires, 27.5 for 27.5-inch, 29 for 29-inch).
- If you have fat tires (4 inches+), the effective rolling diameter is slightly larger. Add 1 inch to the rim diameter for a closer reading.
Speed Limit (P07)
- Common EU-class displays cap at 25 km/h (15.5 mph). Setting P07 to 99 often removes the limiter entirely.
- On some controllers, the limit is hard-coded and ignoring P07 does nothing – the only workaround is a firmware flash or physical shunt mod.
Verify the Change
Ride a measured mile (use GPS) and compare your display’s reading with the GPS distance. If off, use P15 (speed calibration) to adjust percentage: divide true speed by display speed and multiply by 100. For example, if GPS shows 22 mph but the display reads 20 mph, set P15 to 110% (22 ÷ 20 × 100).
Pedal Assist Levels and Voltage Settings
Pedal Assist (P05, P11, P12)
- P05 sets how many assist levels the handlebar controller can cycle through (e.g., 0–5 gives 5 steps plus off). A higher number (9) lets you fine-tune power, but many riders find 3–5 levels sufficient.
- P11 (sensitivity) determines how many pedal rotations before the motor engages after you stop pedaling. Lower numbers (2–6) give a snappier response; higher numbers (18–24) are smoother for urban riding.
- P12 (start power) controls the initial torque burst. Set too high (5) and the bike lurches forward; too low (1) and the motor feels weak from a standstill.
Practical branch: If your bike jerks forward every time you start pedaling, first try lowering P12 from 3 to 2. If that doesn’t help, increase P11 to 14 (making the sensor less sensitive). If the jerkiness continues after both adjustments, the pedal-assist sensor may be misaligned rather than a software issue – check the magnet disc on the crank arm for cracks or debris.
Voltage Setting (P03)
- This must match your battery’s nominal voltage (36V, 48V, etc.). Setting it lower tells the controller to cut off earlier (under-voltage protection kicks in too soon). Setting it higher lets the controller draw current at a voltage the battery can’t safely deliver, risking over-discharge damage.
- Find the correct value on your controller sticker (often printed near the power connector). If missing, check the battery label and set P03 to that voltage.
Stop/Esclate Threshold (repeat for clarity): If the bike won’t power on after changing P03, immediately power off, remove the battery, and restore P03 to its previous value. If you didn’t note the original value, set P03 to the battery’s nominal voltage (e.g., 48V for a 48V battery). If the bike still doesn’t run, do not attempt to ride; take it to a shop that can test the controller with a multimeter.
Factory Reset and What NOT to Change
Factory Reset (P20)
Set P20 to 1 and hold the power button for 5 seconds. The display will revert all P-settings to factory defaults. Do this only if you’ve lost track of changes or the bike behaves erratically.
Settings to Leave Alone
| Setting | Why |
|---|---|
| P08 (Phase current limit) | Exceeding the controller’s rated current melts the MOSFETs. |
| P13, P14 (Calibration) | These require external measurement equipment and a known reference. Changing without data corrupts the controller’s internal logic. |
| P18 (Motor phase angle) | Switching from 120° to 60° incorrectly causes the motor to stall or overheat. The correct angle is printed on the motor housing. |
| P19 (Communication protocol) | Setting this to the wrong protocol (CAN vs UART) results in a dead display that won’t communicate with the controller. |
FAQ
How do I unlock the speed limit if P07 doesn’t work?
If your display ignores a P07 setting of 99, the controller firmware has a hard cap. A metal shunt across the current sensor wire can bypass it, but that voids warranties and may overheat the motor. The legal route is to buy an aftermarket controller that supports higher speeds.
Why don’t my settings save after turning off the bike?
Displays that require a confirm step (hold M or + for 2 seconds) will lose changes if you power off without saving. Also, some low-cost displays reset if the battery is deeply discharged – charge the battery fully and retry.
Can I use these settings on a Bosch or Shimano system?
No. Bosch and Shimano displays hide P-menu access behind dealer-level diagnostics. You can adjust assist levels and speed limits only through a shop’s software or a third-party Bluetooth dongle (like the Bosch BES3 or STEPS EC).
What does P15 (speed calibration) actually do?
P15 is a percentage multiplier applied after the wheel speed sensor and wheel size (P06). If your display reads 20 mph but GPS says 22 mph, set P15 to 110% (22/20 × 100). This fine-tuning is safer than guessing wheel diameter.
Explore This Topic
- Back to Controller & Display
- Back to E-Bike Resources
Related guides in this cluster:
– Hub Drive vs Mid-Drive E-Bike Motors: Complete Comparison Guide
– E-Bike Speed Unlock Guide: How to Remove Speed Limiters by Brand & Model
– E-Bike Serial Number Location Guide: Where to Find It on Every Major Brand
– E-Bike Battery Compatibility Guide: Replacement Options & Cross-Brand Alternatives
Ryan Williams has spent over 8 years testing, repairing, and writing about electric bikes. He has personally ridden and reviewed 150+ e-bike models from brands like Lectric, Aventon, Rad Power, Super73, and dozens more.
Before founding EBIKE Delight, Ryan worked as a bicycle mechanic for 5 years at independent bike shops across California, where he specialized in e-bike conversions and electrical system diagnostics. He holds a Certificate in Electric Vehicle Technology from the Light Electric Vehicle Association (LEVA).
Ryan’s work has been cited by Electric Bike Report, Electrek, and BikeRumor. When he is not testing the latest e-bike on California backroads, he is in his workshop tearing down batteries and controllers to understand what makes them tick — and what makes them fail.
Areas of Expertise
E-bike performance testing and real-world range verificationBattery diagnostics, charging best practices, and safetyBrand comparisons: Lectric, Aventon, Rad Power, Super73, and moreError code troubleshooting across major e-bike systemsE-bike laws, registration, and compliance by state
Ryan believes every rider deserves honest, hands-on information — not marketing hype.