Error 27 on kingsong s22

[Dougev]

I have pedals going up and down, and error 27 coming up, one battery out or at least the bms. It wasn't I don't think due to an incomplete update, and I dropped the wheel in ice the day before....but, connections seem fine, no visual damage to bms. Now what?  

Should I try and reset the signal by shorting two points via eucupgrades video? Or can I test functions to see where the damage is?

[novazeus]

i have the same problem today after charging. i haven't done any updates for weeks. rode it last night for about 6 miles, no problems. battery was down to 70% and after the charger finished, i got the error message and complete tiltback. bms error not communicating with pack one. no voltages registering. put it outside alone, and turned it back on, said battery pack one ok. works normally but i'm not riding it until freemotion and king song figures this out. this is happening to lots of s22's. 

[thtliife]

Guys I had this exact error this morning after updating from firmware 2.25 to 2.27  

After a little research I found the error means one of the bms units is not communicating with the mainboard. 
 

this can be caused by a hardware fault, but if all  you did is update firmware, it is likely that it just means one of the bms units had a failed update. 

i fixed my s22 pro without even having to open it. 
 

all you need is an iPhone (or  a friend with one)

i used the SoftTuner app from here:

https://apps.apple.com/au/app/softtuner/id1506122805

these are the steps I took:

Opened the app, tapped the Bluetooth icon at top right to scan for my euc.
(The app reported to me that the right bms had a communication error immediately after connecting)

Next I tapped firmware upgrade, then bms firmware upgrade (mine was at v2.15)

I think you should update to the same or newer firmware, I wouldn’t recommend downloading the firmware if you can help it.

I used v2.17. The app told me it was not a matching model, but I ignored that, as the model listed in the firmware was indeed ksn-s22.

The upgrade took about five minutes, but reported success. 

After a reboot, the error 27 was gone, and my euc now works again. 

[thtliife]

Small typo… and I can’t edit posts yet..

 should have read:

I think you should update to the same or newer firmware, I wouldn’t recommend downgrading the firmware if you can help it.

[Cassy0110]

Error code 27 typically indicates an issue with the BMS, which could be caused by a damaged or faulty battery cell.

[misterdalto]

On 4/20/2023 at 2:48 AM, Cassy0110 said:

Error code 27 typically indicates an issue with the BMS, which could be caused by a damaged or faulty battery cell.

error 27 is indeed bms error, however, it is truly just an indicator the BMS communication has been interrupted to the board. the smart BMS has several error numbers that define more specific failure point such as cell level failures; 
Now, the cause of interrupted communication between the BMS and the control board can source from multiple reference values, but the actual issue is a lack in communication.

• failed firmware update,
• the bms communication cable not being fully seated or,
• another a separate BMS issue that results in the BMS entering protection mode - typically resolved by a long-press of the hardware reset button on the left-underside of the BMS about 2/3 up from the bottom. Hardware reset button is only functionally enabled on batteries running BMS firmware 2.11 or newer. For manual reset you must short the reset circuit on the BMS board
• it would be after those scenarios have been elimination, to suspect failure of individual cells or cell groups without prior need to investigate the battery (accident, crash, water, etc) then, its the trusty 'ol multimeter, and beyond, but hopefully never a failure beyond this point (optimism)