The US time zone wrap has all the news on what drove the USD

(ICYMI : The FOMC! ... ForexLive Americas FX news wrap: Dollar jumps on the FOMC)

There was a retracement, USD/JPY back from circa 112.50 highs to circa 112.10. There was also a little nervousness around the UN / Iran nuclear discussion contributing to those early (early Asia time) lows.

At the UN ... well .... nothing: EU Mogherini says no discussion on changes to Iran nuclear deal

And, as noted in that post, its helped USD/JPY to regain, and surpass its US highs.

Updates: