Why is my 2005 Dodge ram abs and brake light on?

The 2005 Dodge Ram abs and brake light on causes are a faulty speed sensor or low brake fluid. The vehicle speed sensor (VSS) measures transmission/transaxle output or wheel speed. The ECM uses this information to modify engine functions such as ignition timing, air/fuELRatio, transmission shift points, and to initiate diagnostic routines. Without a valid speed signal from these sensors, the PCM will not be able to correctly control the shifting of gears within the transmission. This may cause the transmission to shift roughly or more quickly than normal.You can still drive the vehicle, and the brakes will still work, but on slippery surfaces, You will have to manually pump the brakes Yourself to avoid wheel lockup and sliding (just like we did back in the days before there was such a thing as antilock brakes).