2000 ml 320 possible sensor problem?

[Pepperusmc]

I have a small issue with my ml 320, when I start the truck the needles on the instrument cluster seem to hesitate for a few seconds then begin to work properly. Not sure if this is normal but it didn't bother me to much, but upon returning from a drive when I turn the ignition off the needles begin to rapidly jump up and down then stop after a few seconds...has anyone ever experienced this and if so any ideas as to what may cause this? There are no codes to report but I thought it may be a speed sensor....thanks