I've been dealing with this for a few months. It seems, there is nothing you can do. You'll need to contact the CA BAR referee.
After several 'not ready for testing' smog checks and dozens of drive cycles including trying the warm up tips I found in the forum; Alex at Elite OC helped determine it was a software issue and to contact the smog ref.
However, when I contacted the ref, they said they researched the issue and spoke to Karma, then they advised me that I should take it and have it inspected at the dealership; then get documentation showing 'nothing can be done'.
The issue has to due with a CA emissions change, stating any car 2010 or newer can not have ANY faults stored in the ECM.
I took it to Rusnak in Pasadena. They are familiar with the issue and they were kind enough (they didn't charge me) to look at it and provide the documentation . I now have another appointment with the referee scheduled.
To paraphrase the letter "The car will have to to a BAR referee. Included is a a copy of the KarmaSync DTC showing the U0291 is stored in the CIU which is an infotainment unit, not emissions related (ECM and HCU). There is no update/DTC to correct."
DM me with your email and I can send you a scan.
Last edited by aaron0k; 11-11-2020 at 02:29 AM.