Please help

Hello, how are I adrian and I am new here I have a Renault Megane 5 doors of the year 2000 1.9 dt and I have stopped working the velocimetro needle but the accountability account if it works. The car does not have the speed sensor in the gearbox but it works with the ABS. But the Light of the ABS works well, when I start the car, the few seconds go out, if someone has an idea that it can be or how to solve it would appreciate the information. Greetings to all and I hope someone has the solution