As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FWD EQPT VAL YELLOW MESSAGE APPEARED WHILE ENTERING RUNWAY FOR TAKEOFF. QRH PROCEDURES DID NOT REMEDY.AC RETURNED TO THE GATE (BTB) AND MTX GROUNDED ACFT , MTX DEFERRED THE FWD EQUIPT. VALVE IAW MEL ABX-21-58-8-1-1. AND RETURNED AC TO SERVICE.