Odo "Error" Message

My odometer reads "error" sometimes and flashes back and forth between the mileage and "error". The odo still accrues mileage correctly even when it's reading error. Any ideas?

This is the digital dash. The error can come from the odometer itself, the wiring to and from the odometer. I had a problem on my '89 and it turned out to be a poor connection at the back of the instrument cluster