As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) EICAS CAUTION MESSAGE FOR GEAR DISAGREE WHEN GEAR SELECTED, ALL INDICATION TO NORMAL AFTER SEVERAL SECONDS. AFTER TROUBLESHOOTING AND AFTER THE REPLACEMENT OF 3A AND 3B HYDRAULIC PUMPS WITH A NIL FIX, THEY ISOLATED THE PROBLEM TO BE THE MAIN LANDING GEAR ISOLATION VALVE.REPLACED THE MAIN LANDING GAR ISOLATION VALVE. GEAR SWING CARRIED OUT AND CONSIDERED SERVICEABLE.