After visiting the midwest site under trouble shooting section, I found out that it was the axle nut loose and it was enough to trigger the ABS light on and the speedometer to malfunctioned. Thanks for reading just in case you are having same issues.

I have a 2000 S40 with over 180K miles on it, yesterday, when I was backing out from my garage, I heard a short noise (pump) under the hood and 10 miles later while trying to stop, my brake pedal was spongegy and pulsating. Continued driving on the interstate and my dashboard light came on for ABS a...