flashing instrument panel

Your Instrument Cluster circuit board is probably defective. I suggest you go to your local dealership to have them inspect and diagnose your concern.

there is a way to reset the computer that controls the speedometer. turn the ignition key backwards so it is on alternate power....then press in and hold the odometer button, maybe for about a minute... you will wait unti a message appears in the odometer screen, you can then let go and in a few seconds(10 -15) you will see your odometer running thru and checking itself you will see your speedomter move around within a minute it should be reset. restart you minivan... hope this helps.