On April 14, 2014 at 10:40 MSK (06:40 UTC) the Strategic Rocket Forces successfully launched an RS-24 Yars ballistic missile from the Plesetsk test site. The missile was launched from a road-mobile launcher. The missile carried multiple warheads, all of which reached their targets at the Kura test site at Kamchatka. According to the official statement on the launch, it was conducted to test reliability of the production series of missiles manufactured at the Votkinsk Machine-Building Plant.
This is clearly the "serial production test" that was listed by the Rocket Forces as it announced its launch plans for 2014.
As it turns out, it's been a while since Russia tested a road-mobile RS-24 - the last record I could find is a test in November 2008. There was a plan to test RS-24 in 2011, but there was no launch that year. Of course, a silo-based version of the missile was tested in December 2013, but that's a somewhat different matter