Pre-arm check error message


i have Navio2 flight controller running arducopter 4.0.3.
I have calibrated and setup everything.
THe problem is that when I am in Loiter mode, the pre-arm Status is always Not Ready and it shows that there are 2 errors (Z/altitude control error and X/Y position control error).

What do these pre-arm check errors mean ? How to fix them so that my pre-arm status become Ready ?

Does the drone have a full GPS position lock? Are you trying this indoors? If so, try again outside in clear view of the sky. If the GPS has never had a lock before, or it’s been a long time, it will take a while to initialize.


the drone has a good GPS lock… It has a 3D dpgs indication when I open mission planner and around 14 sats with hdop 0.8.

The drone is indoors next to a window.
Can this still be the reason even though I have a good GPS fix indication?

I could try outdoors anyway.

Thank you

It looks to me like an EKF issue. try it outside and let it sit for a while with a clear view. Might also be a good idea to update the firmware to the latest version. 4.0 is pretty old.


i upgraded to ardupilot v4.3.7. And tested the drone outside. The pre-arm checks now show normal but I have other problems. I cannot fly in Loiter mode because it looks like the drone starts acting crazy and cannot control it. I also received the message “EKF3 IMU_ground mag anomally, yaw realigned”.

I have uploaded a very quick data log file when i tried to fly in loiter mode. I dont understand what is the problem.

Thanks a lot for your help