What would cause a stoneridge tacho to record driving time while the vehicle is stood? I know it sems like a strange question but it happened today. One of our Scania’s tipping a tank and using the PTO and the tacho has recorded the whole time as driving, its come out on the print out as driving aswell. I know it will have to go in to be sorted but I was wondering if anybody else has heard of it happening, if this is a common problem, and what may of caused it 