My van is not shifting speed and trans axle light is flashing
My car has 151000 miles.
My car has an automatic transmission.
The shifting is controlled by the transmission control module and if the shift light is flashing then the module is detecting a problem in one of the sensors (like a speed sensor which will cause the module to set a code and go into a failure mode and will shift rough). This is so you do not get stranded on the road and can take it to a service facility and get the computer scanned and diagnose the codes stored.