As promised MINI has been working (at times with the help of MINI enthusiasts) to eliminate the dreaded Yo-Yo issue that has plagued some Cooper S's for over two years now. Now it appears they may have a solution. But first for those who aren't familiar with the Yo-Yo issue here's an excerpt of an article we ran last January about the efforts of one enthusiasts better understand the problem:

Ryan Malcolm (Ryephile on North American Motoring) has researched this subject extensively and gives us the following insight into the problem: “The Yo-Yo is the oscillation of the supercharger bypass valve, which is excited by an under-damped P.I.D. throttle body servo controller. The parameters of the Yo-Yo occurring are simple: typically during medium acceleration, on-boost, and with the throttle pedal reasonably steady. Amplitude of the Yo-Yo seems to vary per vehicle, ranging from imperceptible to an almost violent bucking.”

You can read the entire article here.

Recently Ryan wrote us again to let us know some details of the upcoming official MINI fix:

The V38 (or actually CD version 38) portion of the MINI code was completed as of Monday evening. The V38 is specifically designed to eradicate the Yo-Yo. Currently, MINIUSA is allowing select customers that have severe Yo-Yo to send their ECU's to the New Jersey headquarters through their local MINI dealership only to have the new software uploaded prior to its dealership distribution in June.

We'll hopefully have a full review of V38 in the coming weeks.