Mrslithers

So today I had to go to my brothers to get some parts from my 450R. When i first jumped in the truck, I put it in drive and as soon as I tapped the brake, my driver side tire only locked up completely. I put it in park and pumped the brakes and it did it again. So I drove it around our apartment parking lot and it seemed to go away so I headed on down the road. I started comin torwards an empty stoplight intersection and hit the brakes and that driverside tire locked up again puttin my butt in the ditch (wet roads). It just kinda happened out of the blue. Also, my check engine came on when it was doin it. Anyone have any ideas? I hate dealing with brakes.