Whirlpool Cabrio washer troubleshooting

Hi, My washer has stopped working ,was gonna see if you guys could guide/assist me to troubleshoot it?Its starts to agitate and just stops with a F 51 error and a beeping sound.It doesnt have problems until about 10-15 mins into the cycle.Ive attached a short video of whats its doing. It almost looks/sounds like the motor is losing power(or running out of juice) ,like it needs charged.I know that isnt whats wrong but just what it looks/sounds like that right before it gets the F error Model # is WTW7600XW2 Thanks in advance! https://www.youtube.com/watch?v=L_Df27g743U&feature=youtu.be