2017 Hino 258 - No Acceleration


New Recruit
Hey Guys. New here. Have a Hino 258 with no acceleration. will not go over 5mph. Checked the brake switch correspondence and they are both off and on when they should be. Did as much testing through DXII as I can think. No engine lights. Air brake truck. With the parking brake on, truck has enough power to push through the brakes, like there is nothing wrong with it. Once the brake is off and in gear, it will scoot to 5mph and stay there. Any suggestions?