Error 40021 (Gimbal IMU) is one of the most common faults on DJI drones. The gimbal stops stabilizing, the camera drifts or hangs crooked, and the drone often refuses to take off. Until now that meant shipping it to a service center, waiting weeks and paying a few hundred zloty.
What is error 40021?
40021 is a fault in the gimbal's IMU — the sensor that keeps the camera level. When the IMU calibration data drifts (after an impact, a crash, a ribbon-cable swap or a firmware update), the drone reports 40021 and locks stabilization.
The fix: GimbalDoctor
GimbalDoctor is our own Windows application that resets the gimbal IMU data and clears error 40021 — using the exact command professional service centers use. Connect the drone to your PC with a USB cable, launch the app, click "Fix error 40021" and the gimbal works again in moments.
Since October 2026 we support three models:
- DJI Mini 2 (WM161)
- DJI Mini 3 (WM163)
- DJI Air 2S (WM232)
What else does GimbalDoctor do?
- Gimbal IMU calibration and data reset
- Real-time diagnostics — serial number and device status
- Automatic online updates
How much does it cost?
A GimbalDoctor license is 350 PLN net + VAT and covers 2 months of use — a fraction of the price of a single authorized repair, and the tool stays with you for future faults.
How to start?
Download the app from drone-partss.com/app, activate your license and repair your drone at home. Questions? Message us — we'll help match the right solution to your model.