As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BRK FAIL YELLOW CAS ILLUMINATED - BRK FAIL YELLOW CAS MESSAGE IN FLIGHT. COMPLRETED CHECKLIST AND DIVERTED. INSPECTED BCU CANNON PLUG, NO DEFECTS NOTED. PERFORMED BCU FUNCTIONAL CHECK AND NOTED LH BRAKE PRESSURE TO BE VERY IRRATIC AND SHOWING BETWEEN 15-555 PSI WITH BRAKES NOT APPLIED. REPLACED PRESSURE TRANSDUCER AND BCU AND SYSTEM TESTED GOOD.