The D$ light flashing indicates an automatic transmission fault but yo are lucky in that the Vehicle Speed Sensor (VSS) is a key sensor input for transmission controls. It operates the speedometer and is necessary fro cruise control as well. Common failure relatively easy to change and relatively inexpensive part (compared to a transmission failure).
my car is doing the samething the D4 light is flashing and speedo problems and from reading all the information I think its the VSS, my question is can I do it myself and what else should be done at the same time. Thank you.