So I'm driving to work cruising doing like 90mph in the express lane when traffic starts to slow me down so i hit the brakes and I'm getting closer to the car when all of a sudden my brake pedal gets hard and I'm not slowing down at all so at this point I'm like scared as hell I'm about to crash then the brakes get normal and I skid about an inch away from the car ahead of me I'm sitting in the car like WTF just happened

At that time 3 lights came on on the dashboard

Uploaded with ImageShack.us they are ABS, TRAC and TRACS OFF

I ran a scan with a OBD 2 scanner but no codes pop up I was wondering if anyone had this problem before and can somewhat help me single it out I drove it home and nothing was wrong then the lights came on again leaving later on that night but my brakes were still working fine I'm thinkning its a master cylinder or the ABS pump but I'm just a rookie at these things

Any help would be appreciated

 

It looks like your brake booster is bad. Does it feel like you don't have power brakes?

 

No it feels normal thats the weird thing my brakes feel fine there is slight vibration but that could be because of my rotors I'm gonna change them when I get a chance to see if it makes a difference

 

if the pedal got hard is because you lost power assist or the ABS system was kicking in witch makes the pedal feel hard but you would experience some kind of violent pedal vibration. Since i didn't see you mention anything about that i would go with brake boost diagnosis first.

 

oh and the reason your scanner didnt read anything is because most likely you got an engine computer scanner(like most people). not all scanners read ABS> etc.

 

My wifes Chevy equinox is doing this, and it's an abs sensor on one of the wheels gone to ****.

If you didn't get the freakout like vibrations stated in the quote, then definitely check the booster first. Drive the car around town and see if you get these vibrations before or after the pedal goes hard as a rock. If you do, start checking the ABS system.