  We present an updated description of the Planck Low Frequency Instrument
(LFI) data processing pipeline, associated with the 2015 data release. We point
out the places where our results and methods have remained unchanged since the
2013 paper and we highlight the changes made for the 2015 release, describing
the products (especially timelines) and the ways in which they were obtained.
We demonstrate that the pipeline is self-consistent (principally based on
simulations) and report all null tests. For the first time, we present LFI maps
in Stokes Q and U polarization. We refer to other related papers where more
detailed descriptions of the LFI data processing pipeline may be found if
needed.
