speedometer/abs

2000 windstar...about 2 years ago abs light went on and speedometer started reading half speed...ie going 60...registers 30...also my mileage registers half...go 60 miles says u went 30...anyone know what this is? is the abs and sppedometer related?

They are indeed linked togather. ABS works by monitoring the speed at which a particular tire is spinning compared to other tires. It accomplishes this by reading a "Speed Sensor" which is mounted on the brake caliper or sometimes on the wheel assembly.

I am 100% positive that one or more of these sensors are shot. That justifies everything else also because if sensor is malfunctioning, the speedo and computer is getting false input.

I would highly (and I cannot stress it much more) recommend for you to take your vehicle in for service. Malfunctioning Speed sensors can trigger ABS when not needed or always when you brake - offcourse unnecessarily.

my 2c worth.

There is also a "speed sensor" that reads the rpm of the trannie output shaft. This gear-driven-creature has an elect connector that you might check first to make sure its secure and not corroded or something. The basic part number is 9E731. One screw holds it in place, RH rear of trannie... near the RH drive shaft.