Volvo: 1999 S70 ABS and Brake light, abs light, abs brake

Question
I recived a ABS light read code bad speed sensor. Everything was fine for 6 months. Now the ABS , Brake warning and the kicker the ondomneter and speed go off. Car keeps running I can clear codes but now and then it happens again. Unable to find problem at Volvo shop. A friendy tech suggested the ignition switch (which was replaced 5 years ago.
Any thoughts. Thank You

Answer
Mike,
If you are still getting fault codes in the ABS then you may need a control unit. The speed signal goes through the ABS control unit and then the dash cluster. You can also wiggle the ignition key to see if the switch makes contact and things begine to work.