I had last Sunday also the problem of "Check electric vehicle system" warning:
When I tried to startup my Kia Soul EV by pressing the Power button, the above error message appeared. I could not drive.
After several times stopping and starting via the Power button, the error message was gone.
The problem was not the 12V battery, which is already changed a year ago.
The car was charged at a public charger from 60% to 100%. The car was fully charged (100%) and the public charger was stopped.
Unfortunately I had to charge in the sun. Outside temperature was 27 degrees Celsius. Normally I try to charge in the shadow and mostly I charge till 80%.
Maybe cooling of the batteries was not working?
Later I did a readout with Torque Pro of the diagnostic error codes. The following was reported:
Fault log report generated by Torque for Android
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P1BA7: Unknown code - More information may be available on the web
P1B77: Unknown code - More information may be available on the web
I did search for these error codes and found this:
https://www.obd-codes.com/tsb/2017/kia/niro-hybrid/
Communication Number: PS491, Date: 2017-02-27 Category: 111000 ELECTRICAL SYSTEM:BATTERY
Summary: PITSTOP: Voltage Protection Device (VPD) DTCs P1BA7 and P1B77 -
The Voltage Protection Device (VPD) (1) is mounted on top of the HV battery pack. If the HV battery overcharges, the battery cells/modules/case can swell. If swelling occurs, t
I did not have this problem again, but still informed the dealer about this problem. They will come back with an answer coming Monday.