08 Express 2500 4.8 speedometer/trany
The speedometer intermittently fails to display any speed
as I move away from a stop.
The failure only occurs as I move away from a stop it never falls to zero while moving
As I move away from a stop, the meter remains at zero.
As long as I am in motion, the meter will always remain at zero.
With the van in motion and the speedometer reading zero,
the transmission will not shift out or 1st gear.
To work around that issue, I stop the van for a few seconds.
When I come to a complete stop, then start moving,
the speedometer will function normally.
The meter never fails as long as the van is in motion.
As said, this problem is intermittent.
What would be the first step toward a solution for this problem??