EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude
Flight Crew Took Evasive Action
Aircraft
During a climbing right turn off the EWR1 Departure the captain who was the pilot monitoring and I noticed an unusual traffic return on our TCAS display. At 2;500 MSL in clear VFR conditions there was traffic at our nose and altitude at a range of 3 miles; however we did not see any traffic outside. We were assigned a turn to heading 040 and a climb to 7000 as we turned towards MERIT intersection. Shortly after we were given a resolution advisory to descend aggressively at a rate of 2;500 FPM. Although we never saw the traffic I followed the RA and made an aggressive flight idle descent from 2;500 feet. During the process we saw 'traffic no bearing' displayed on our TCAS. The RA stopped at 2000 FT MSL and I started a climbing turn towards our assignment. We never saw any traffic and the aircraft displayed disappeared as we neared the target head on. ATC also did not see any primary or secondary targets after we queried them. There were no other issues with the flight. In my opinion this was an automation error. The target showed [straight ahead] at our altitude and close range for a potential impact. Neither the captain nor I ever saw an airplane which seems unlikely considering the range of the target.
EMB-145LR First Officer reported responding to what was probably a false TCAS RA.