Vacuum Modulator for C4 Automatic Transmission, Single Outlet

This is a vacuum operated shift module for a C4 automatic transmission. This controls the shift points of the transmission. Installs into the very rear of the transmission case and uses a vacuum line leading to the intake manifold. If your transmission is short-shifting or shifting really hard, this is a possible solution. This particular modulator is a single vacuum port module and has a yellow indicator dot.