04 3.5 Engine management mil light - f m s
I have a strange problem with the MIL light.The light is on all the time and the power is down,my scanner says there is no fault codes stored and the system is normal but when I start the engine and read the data stream, the speed sensor is fluctuating between 12 and 135 mph whith the car stationary.I first thought of an air flow meter problem as there are no codes stored but this speed sensor has me stumped,does anyone know if this has happened before as the local dealer is no help at all.
PS,it has an automatic gearbox.