Pinned Electric Knowledge Base Article
1. Overview
This article explains how to diagnose and repair throttle errors that may occur on 2025 and 2026 Sur Ron Light Bee and Ultra Bee models equipped with a VTB Aetos Controller.
Some 2025 and 2026 Light Bee and Ultra Bee throttle assemblies can produce unstable throttle voltage readings, which may result in throttle errors or abnormal throttle behavior when used with a VTB Aetos Controller.
By the end of this article, you'll know how to identify the issue, enable Throttle Grip Compatibility Mode in the VTB App, and properly recalibrate the throttle.
⚠️ Important: If the throttle voltage reads 0V, do not begin throttle calibration from 0V. Slightly twist the throttle until the voltage reads between 0.85V and 0.89V before starting calibration. Failure to do so may result in abnormal throttle response.
2. Prerequisites
Required Permissions:
- Access to the VTB App
- Ability to connect to the VTB Aetos Controller via Bluetooth
Software/Tools:
- VTB App (latest version)
- Bluetooth-enabled mobile device
Time Required:
- Approximately 5–10 minutes
Hardware/Components:
- 2025 or 2026 Sur Ron Light Bee or Ultra Bee
- VTB Aetos Controller
- Factory throttle assembly
Reference Materials:
- VTB App
- VTB Aetos Controller Setup Guide
⚠️ Important: This procedure only applies to throttle errors caused by unstable throttle voltage readings. Ensure your controller is connected to the VTB App before beginning.
3. Step-by-Step Instructions (with Visuals)
3.1 Diagnose the Throttle Voltage Issue
Power on the bike.
Press the down button on the left side of the dashboard twice consecutively.
Observe the throttle voltage displayed on the dashboard.
If the voltage reads 0V or fluctuates around 0.85V, the throttle compatibility issue has been identified.
A properly functioning throttle should reach approximately 4.0V at full throttle.
Expected Result:
You should see the current throttle voltage displayed on the dashboard.
Figure 1 — Dashboard displaying throttle voltage.
Tips
- Voltage readings around 0.85V indicate the known throttle compatibility issue.
- A full-throttle reading should reach approximately 4.0V.
- This issue can typically be corrected through compatibility mode and throttle recalibration.
3.2 Enable Throttle Grip Compatibility Mode
Open the VTB App and connect to the VTB Aetos Controller.
Navigate to:
Parameter Settings → Advanced Settings
Scroll to the bottom of the page.
Enable Throttle Grip Compatibility Mode.
Expected Result:
Throttle Grip Compatibility Mode is enabled and ready for calibration.
Figure 2 — Enabling Throttle Grip Compatibility Mode within the VTB App.
Tips
- Verify the controller remains connected during the entire process.
- Make sure Compatibility Mode remains enabled before proceeding.
3.3 Re-Calibrate the Throttle
Navigate to the throttle calibration interface within the VTB App.
If the initial throttle voltage reads 0V, slightly twist the throttle until the displayed voltage reaches between 0.85V and 0.89V.
Begin the throttle calibration process while maintaining the voltage within this range.
Fully twist the throttle to the maximum position.
Release the throttle back to 0.85V–0.89V to complete the calibration process.
⚠️ Important: Do not begin calibration directly from 0V. The travel range between 0V and 0.85V will be included in the calibration and may cause abnormal throttle feel.
Expected Result:
Throttle calibration completes successfully and the controller accepts the new calibration values.
Screenshot:
Figure 3 — Throttle slightly twisted to achieve 0.85V–0.89V before calibration.
Tips
- Always begin calibration at 0.85V–0.89V if the throttle initially reads 0V.
- Use smooth throttle movement throughout the calibration process.
- Verify the calibration completes successfully before exiting the screen.
3.4 Verify Proper Operation
After calibration is complete, check the throttle voltage again using the dashboard.
Press the down button on the left side of the dashboard twice consecutively.
Slowly apply throttle and verify the voltage increases smoothly.
Confirm that full throttle reaches approximately 4.0V.
Expected Result:
Throttle voltage increases smoothly and reaches approximately 4.0V at full throttle.
Screenshot:
Figure 4 — Full-throttle voltage reading after successful calibration.
FULL-THROTTLE VOLTAGE SHOULD REACHING APPROXIMATELY 4.0V
Tips
- Verify smooth throttle response before riding.
- Repeat the calibration procedure if voltage does not reach approximately 4.0V.
- Ensure Throttle Grip Compatibility Mode remains enabled.
4. Pro Tips & Common Issues
Pro Tips
✅ Verify Voltage Before Calibration
Always check the throttle voltage before beginning calibration.
⚙️ Start Calibration at 0.85V–0.89V
If the throttle reads 0V, slightly twist the throttle until the voltage reaches 0.85V–0.89V before starting calibration.
📶 Maintain Bluetooth Connection
Keep the VTB App connected throughout the procedure to prevent calibration interruptions.
🧠 Verify Full-Throttle Voltage
After calibration, confirm that full throttle reaches approximately 4.0V.
Common Issues & Fixes
| Issue | Likely Cause | Solution |
|---|---|---|
| Throttle reads 0V | Factory throttle voltage issue | Enable Compatibility Mode and recalibrate |
| Voltage fluctuates around 0.85V | Unstable throttle signal | Perform throttle recalibration procedure |
| Poor throttle feel after calibration | Calibration started from 0V | Repeat calibration beginning at 0.85V–0.89V |
| Full throttle does not reach 4.0V | Incomplete calibration | Re-run the calibration procedure |
5. Related Articles
- VTB App Installation and Setup
- VTB Aetos Controller Installation Guide
- VTB Aetos Controller Auto Learn Procedure
