I contacted DJI Repair regarding my Mavic Pro on March 19. The DJI Go app was showing an "Ultrasonic sensor error, land immediately error". Before the error appeared  noticed that the drone was not holding its position, even with full GPS signal. Not only was it wavering horizontally, but, with my hands off the controls, it began to ascend uncontrollably. It was only with difficulty, and my pulling on the "down" stick in its full position that I was able to make it descend and then land safely.
I received a reply 3/20, but the instructions were in somewhat broken English.

Here is their instructions:
"We would like to ask some assistance for us to isolate the issue by sending to us a picture or screenshot of the error message as will as a video that would transpired the issue further.

Please do verify to us the needed attachments.

Looking forward to hearing from you soon.
Please note: You will receive an email survey two (2) days after this email if not responded. If you happen to be away and won't be able to answer this email, please disregard the survey and send us an email again at support.us@dji.com. "

I am baffled by the request to create a picture of the message. I copied down the message literally in its entirety. And I do not wish to risk a fly-away. (And how does one get a screen shot when the DJI Go controls entirely the phone??). And what does "as will as a video that would transpired the issue further" mean? I am lucky to be able to control the drone, now they want me to make a video?


I politely replied asking for further clarification, but received no response. Just dead silence.

Support request #1040376


Michael Mason

Hey Michael, sorry for the inconvenience. Just to verify, does the message of Ultrasonic sensor error only appear once? If it pops up regularly, we'd suggest taking a screenshot if applicable. Regarding the drift issue, the video will be helpful to confirm the current status. I sincerely apologize for the confusion.

Also, I've reported this to the Management for investigation. They will check the exact status and try their best to make your experience with us better, we will have someone to contact you for detail later.  

Thanks for the reply Susan.
To answer, during my last day of flying the Mavic, the message happened two times, and after the Mavic started to fail to hold position, but horizontally, but more strikingly vertically (it started to ascend fairly rapidly and did not immediately respond to control input to descend. Only after some 3-4 seconds of full "descend" input from the left control stick did it descend. Hence my anxiety about a fly away or the device getting stuck in a tree.
After the first error warning, I landed the Mavic, checked in the Go 4 app for the status of the Ultrasonic sensors (indication was they were operating normally) plus did an IMU reset and compass reset (just on the off chance they were off, even though Go 4 app indicated they were in normal (green bar) range.
After full power shut down, I restarted and flew the Mavic again. Again same flight instability for a few minutes, the Go 4 app flashed again a (yellow) warning: Ultrasonic error.

I assume you want me to take video using an external device even though the Mavic is unstable. Sounds risky. Who will step up and take responsibility if the Mavic crashes or flies away while the Go 4 app is warning me to "land immediately"?

bobjonesx Posted at 2018-3-23 07:02
Thanks for the reply Susan.
To answer, during my last day of flying the Mavic, the message happened two times, and after the Mavic started to fail to hold position, but horizontally, but more strikingly vertically (it started to ascend fairly rapidly and did not immediately respond to control input to descend. Only after some 3-4 seconds of full "descend" input from the left control stick did it descend. Hence my anxiety about a fly away or the device getting stuck in a tree.
After the first error warning, I landed the Mavic, checked in the Go 4 app for the status of the Ultrasonic sensors (indication was they were operating normally) plus did an IMU reset and compass reset (just on the off chance they were off, even though Go 4 app indicated they were in normal (green bar) range.

Thanks for getting back to us. I've checked your case and sorry to know the issue persists after troubleshooting. The repair case has been created, please refer the email direction and send the unit in after you received the shipping label, thanks!

Hello Susan,
Thanks for the response.
Good(ish) news: thanks to several phone calls to Tech Support, I was able to find a solution. It appears that DJI Go 4 app fails to update properly firmware. It signals that all is in order, but when using Assistant 2, the latter finds errors in the state of firmware that Go 4 could not.
When using As2, I received this message: Firmware incompatibility detected between some modules and current device. Update your firmware?  Confirm/Cancel
Doing the update cured the problem, although it sent me back to v01.04.0000. After I restarted the drone, I then used As2 to update to v01.04.0300.
So, things appeared to be ok on a flight yesterday, but I need to test again tomorrow.

That said, allow me to repeat the message I sent to your Customer Survey in the final section requesting general comments:
"The written contact by your Tech Support was marred by broken, ungrammatical English making my understanding of what you requested rather difficult. Pair that with the lack of response to my emails responding to your emails. Calling in to your support telephone was better, a little, but marred by being repeatedly cut off by your agent when he put me on hold to contact other persons at DJI. Each of your agents promised to contact me within 15 minutes should we get cut off, but the only one to call me back took 4 hours to do so. Given that, I made two more calls to Support. Each time, I was forced to start over describing my problem -- apparently you do not create a support incident that includes all prior contact messages between the customer and your Tech Support. Not efficient, nor useful. Further evidence of the lack of chain of messages maintained by Support was an email sent me by Gabriel G on Mar 24, 7:42 CST which required of me original purchase invoice, activation email and such. Rather extraordinary!!! As this unit was one you sent me as replacement under DJI Care Refresh, so naturally I have no purchase receipt for THAT one. But apparently DJI discards all prior messages in support incidences and this explains Gabriel's rather clownish, clumsy request for information. Again, this is a replacement drone, sent to me no more than 3 weeks ago, and Gabriel asks me to review DJI's warranty policy.
Luckily, one of your tech support people alerted me to the fact that upgrading firmware via DJI Go 4 app is not as effective as doing so via Assistant 2. True that is, as Assistant2 uncovered a firmware error that Go 4 did not. Seems to me you need to spend more time debugging your software."

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I affirm that Tech Support agents seemed genuinely eager to help (including yourself). But your Tech Support infrastructure seems fully chaotic and disorganized. I suspect in the future I would be better off finding a third party repair service and pay them directly for quality work rather than receiving a replacement drone that was prepared in a faulty manner. That way, I won't have to continually prove that I exist, the drone legitimately exists, that it was activated,  that I have a legitimate DJI Care Refresh contract, and that the drone I have directly comes from your repair shop.
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I am happy to hear any suggestions you have.
Michael

bobjonesx Posted at 2018-3-26 18:08
Hello Susan,
Thanks for the response.
Good(ish) news: thanks to several phone calls to Tech Support, I was able to find a solution. It appears that DJI Go 4 app fails to update properly firmware. It signals that all is in order, but when using Assistant 2, the latter finds errors in the state of firmware that Go 4 could not.

Hi Mickael, glad to know the issue was figured out in the end, thanks for getting back to us, your feedback is very important to us, we understand that there are things we need to improve and we'll never stop moving forward. We will keep learning from this and do more training to our support team and optimize our workflow, keep improving the quality of our products and APP, hope you will have a better experience with us in the future.

Ok!!

bobjonesx Posted at 2018-3-27 11:20
Ok!!

Should you have any further questions in the future, please feel free to contact us, we'd glad to help.