A similar fault occurred in my i-miev (2012).
A Yellow exclamation light lit up in the dash, no hv contact/traction. ODB readings gave DTC error code U1111, which could be resetted, but came back on every start. And I don't trust my OBD-reader a lot.
Culprit ended up being the connection between the resolvel housing(?) and the motor controller area (under the truck hatch). An earlier owner had fixed it before, but the fix had failed (maybe corrosion?(It is salty and snowy here), or maybe vibrations (wire was hanging and had much freeplay), or something else idk). Problem ended when I fixed the connection (soldered, could not crimp, not enough space without ruining the harness).
Broken connection:
[ATTACH=full]1930[/ATTACH]
The fix, before sealing it in:
[ATTACH=full]1931[/ATTACH]
Status before debugging more forcefully:
[ATTACH=full]1932[/ATTACH]
Thanks a lot for the help, I would not have known where to look for without this forum post 
ps. did also replace the 12v battery also, but it had ran out a while ago & was out of it's service life anyway.
pps. The place for the connector is convenient, but very prone for dirt/salt/water/debris
