Britt Reid is fighting back in his car crash case -- the former Kansas City Chiefs coach pled NOT GUILTY Monday to a DWI charge, court records show.
The 36-year-old is accused of drinking and driving prior to a violent wreck in Kansas City back on Feb. 4 that badly injured a 5-year-old girl.
Officials say Reid had a .113 BAC when measured around 2 hours after he allegedly crashed his pickup truck into others ... and claim Reid was also going 83.9 MPH in a 65 MPH zone just seconds before the collision.
Reid -- son of Chiefs head coach Andy Reid -- was ultimately hit with one charge of felony DWI ... but TMZ Sports has confirmed Britt entered a plea of not guilty Monday.
Britt also had the conditions of his bond adjusted Monday ... with the judge in the case allowing Britt to drive, so long as he uses an interlock device forcing him to pass a breathalyzer test every time he gets behind the wheel.
Britt is due back in court in late July for another hearing in the case.
The little girl who was injured in the crash, meanwhile, has since returned from the hospital ... though her family says she still has a long road to full recovery.