Could a damaged speed sensor cause milometre to stop working

Hi a few months ago i noticed that the milometre on my Audi coupe had stopped working. I removed the instrument cluster and totally took it appart and everything seemed in tact. I even removed the milometre which is inside a clear casing and there were wires inside that all looked in tact. The black plastic button which you press to reset the 3 digit last mileage seemed fine. I thought it might of been sticking at first but all was good and the plastic cog was in place as it should be so ive sort of ruled out the instrument cluster but would only rule it out after trying another one in the car. At the moment im waiting for the car to go in the garage next Monday to have the steering rack replaced. Whilst looking around the engine bay i noticed thst power steering fluid that leaked from the rack was all over the speed sensor by the gearbox and i know how corrossive power steering fluid can be so thought that maybe that had damaged the speed sensor which doesnt look great anyway. From what ive seen i think the speed sensor records the speedometre which works fine as it should but i wonder if it could be effecting the milometre. The rev counter works fine too.dont know if its relevant. Any help or opinions would be much appreciated. Thanks