2. Mar 23, 2015. #1. Hi all! I am a complete car novice so bear with my ramblings of text. I have a W reg seicento which has a non working speedo/mileometer. Ive been told to get the electronic speed sensor which is all well and dandy. I have checked the eper and found the part numbers. 46523738 or 46758026, MD4po5.