B757-200
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human-Machine Interface; Situational Awareness
Aircraft Equipment Problem Less Severe
Flight Crew Rejected Takeoff; Flight Crew Returned To Gate
Aircraft; Human Factors
On takeoff at approximately 115mph; 'FWD Access door' EICAS alert came on. Air conditioning cart was used in ZZZ. Forward access door was closed and light extinguished prior to engine start. After 80 knot call I was focused on engine instruments when alert came on. I elected to reject at that time. Proceeded back to the gate. Brake cooling chart applied. Micro switch malfunction or door wasn't fully secured.
B757 Captain reported a rejected takeoff due to an access door EICAS alert.