changing springs on car and found abs sensor broken, so replaced the sensor, now i am getting code for n/s/f wheel speed sensor mechnical failure intermittent. When you start the cra abs light is always on speedo reads iratically eg can do 60mph in first gear although only around 30mph, but once driven for a fw minutes the traction control light and tyre pressure light also come on and speedo goes back to normal.Is this a wiring fault or a faulty wheel bearing?