  We derive the transit timing variations (TTVs) of two planets near a second
order mean motion resonance on nearly circular orbits. We show that the TTVs of
each planet are given by sinusoids with a frequency of $j n_2-(j-2)n_1$, where
$j \ge 3$ is an integer characterizing the resonance and $n_2$ and $n_1$ are
the mean motions of the outer and inner planets, respectively. The amplitude of
the TTV depends on the mass of the perturbing planet, relative to the mass of
the star, and on both the eccentricities and longitudes of pericenter of each
planet. The TTVs of the two planets are approximated anti-correlated, with
phases of $\phi$ and $\approx \phi+\pi$, where the phase $\phi$ also depends on
the eccentricities and longitudes of pericenter. Therefore, the TTVs caused by
proximity to a second order mean motion resonance do not in general uniquely
determine both planet masses, eccentricities, and pericenters. This is
completely analogous to the case of TTVs induced by two planets near a first
order mean motion resonance. We explore how other TTV signals, such as the
short-period synodic TTV or a first order resonant TTV, in combination with the
second order resonant TTV, can break degeneracies. Lastly, we derive
approximate formulae for the TTVs of planets near any order eccentricity-type
mean motion resonance; this shows that the same basic sinusoidal TTV structure
holds for all eccentricity-type resonances. Our general formula reduces to
previously derived results near first order mean motion resonances.
