As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED THAT JUST AFTER ROTATION ENGINE NR 2 VIBRATION TURNED AMBER AT 4.0. CREW REDUCED THRUST TO ENGINE NR 2 WITH VIBRATIONS AT 3.8. CREW STOPPED CLIMB AT THIS POINT AND CALLED MAINTENANCE. AFTER DISCUSSION WITH MX, CREW DID NOT DECLARE AN EMERGENCY, BUT ELECTED TO RETURN TO PHL WHERE THEY LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE W9 HARNESS BAD. MAINTENANCE REMOVED AND REPLACED THE HARNESS AND PERFORMED ENGINE RUNS PER EMB AMM. OPS CHECKED GOOD.