  We develop a controlled high-temperature expansion for nonequilibrium steady
states of the driven lattice gas. We represent the steady state as
$P(\eta)\propto e^{-H(\eta)-\Psi(\eta)}$, and evaluate the lowest order
contribution to the nonequilibrium effective interaction $\Psi(\eta)$. We see
that, in dimensions $d\ge2$, all models with nonsingular transition rates have
the same $\Psi(\eta)$, which consists of a three-body effective interaction
decaying like $1/r^{2d+1}$. The models with the Metropolis rule show
exceptional behavior.
