Quoting from another site:
"Ok I ended up taking it to bmw, really nice mechanic there tested it for me, gave me schematics, told me the metering valve was pooched, just put a new one in and for the first time in months the check engine light is off!! Yay!!"

Here is the link:
Trouble code P2062 [Archive] - Bimmerfest - BMW Forums


Few more:
P2062 Generic DTC: Reductant/Regeneration Supply Control Circuit/Open
Trouble code P2062 - Bimmerfest - BMW Forums