The English version of the CDG website does not mirror the French one...
CDG landside shuttle bus
schedule and routes
Take the #1 bus. It leaves from the curb (not 'inside'), between terminals 2B and 2D. This means you will have to walk to the 'right' end of 2D upon exiting the secure area.
I don't think there is an airside T1-T2 bus for Schengen transfers.