  We study augmentations of a Legendrian surface $L$ in the $1$-jet space,
$J^1M$, of a surface $M$. We introduce two types of algebraic/combinatorial
structures related to the front projection of $L$ that we call chain homotopy
diagrams (CHDs) and Morse complex $2$-families (MC2Fs), and show that the
existence of either a $\rho$-graded CHD or MC2F is equivalent to the existence
of a $\rho$-graded augmentation of the Legendrian contact homology DGA to
$\mathbb{Z}/2$. A CHD is an assignment of chain complexes, chain maps, and
homotopy operators to the $0$-, $1$-, and $2$-cells of a compatible polygonal
decomposition of the base projection of $L$ with restrictions arising from the
front projection of $L$. An MC2F consists of a collection of formal handleslide
sets and chain complexes, subject to axioms based on the behavior of Morse
complexes in $2$-parameter families. We prove that if a Legendrian surface has
a tame at infinity generating family, then it has a $0$-graded MC2F and hence a
$0$-graded augmentation. In addition, continuation maps and a monodromy
representation of $\pi_1(M)$ are associated to augmentations, and then used to
provide more refined obstructions to the existence of generating families that
(i) are linear at infinity or (ii) have trival bundle domain. We apply our
methods in several examples.
