B737 Undifferentiated or Other Model
Aircraft Equipment Problem Less Severe
Flight Crew Rejected Takeoff
Aircraft
Reject occurred on Runway 25 DEN. During the before takeoff check the Takeoff config switch was checked and did not sound. At around 80-85 knots the Takeoff Config horn sounded. The Captain rejected and we exited the runway uneventfully. We advised DEN Tower that we wanted time to run checklist and would advise. We ran the checklist and consulted brake cooling chart and found everything to be normal and none of the items that would cause the horn to sound were evident. We requested flaps 5 data and returned to the runway and took off without any further issues.
[Report narrative contained no additional information].
B737 flight crew reported they rejected the takeoff at DEN at about 80kts when the takeoff warning horn sounded. No cause for the warning was found.