  A systematic analysis of correlations between different orders of
$p_T$-differential flow is presented, including mode coupling effects in flow
vectors, correlations between flow angles (a.k.a. event-plane correlations),
and correlations between flow magnitudes, all of which were previously studied
with integrated flows. We find that the mode coupling effects among
differential flows largely mirror those among the corresponding integrated
flows, except at small transverse momenta where mode coupling contributions are
small. For the fourth- and fifth-order flow vectors $V_4$ and $V_5$ we argue
that the event plane correlations can be understood as the ratio between the
mode coupling contributions to these flows and and the flow magnitudes. We also
find that for $V_4$ and $V_5$ the linear response contribution scales linearly
with the corresponding cumulant-defined eccentricities but not with the
standard eccentricities.
