Ford Focus 1.6 Mk1 - Speed Sensor - Twixer
Had issues with the speed dial dropping to zero, diagnostic test showed a faulty speed sensor. I replaced this 6 months ago and everything was perfect until yesterday when the speed dial became erratic with the dreaded loss of power and the ------ ----- displayed again. In addition the engine management light is permenantly displayed on the dashboard. Everything else on the dashboard is working OK.Any ideas why this problem could reoccur?

Have been advised that the oil seal to the speed sensor has failed again, shorting the power circuit. Any advice on how to fix the oil seal?
Ford Focus 1.6 Mk1 - Speed Sensor - elekie&a/c doctor

The speed sensor is a sealed unit.Can't really see it being a failed oil seal.There are no moving parts.Was this a genuine Ford part or aftermarket?

Ford Focus 1.6 Mk1 - Speed Sensor - amyamandaallen

Mine does this quite a bit.

Dont get an engine management light though. ( thankfully )

Ford Focus 1.6 Mk1 - Speed Sensor - Energyman
My sister had similar problem some years ago, display was faulty, known problem, there was a company that could fix rather than replace. I believe alternator was also a possible cause, contact problems I believe, try googling it