As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAXI OUT THE FWD EQIP VAL EICAS MSG CAME ON, AFTER GOING TO STANDBY THE MSG REMAINED ON. AICRAFT BACK TO BLOCK AND GROUNDED BY MAINTENANCE. MAINTENANCE CLEANED CANNON PLUG OF INTERCON VLVE IAW SWPM 20-60-1AND AMM 21-58-01. MSG CLEAR PER FIM SUPPLEMENT 21-58-00. PERFORMED ENG RUN AND OPS CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.