Dist. Thermal Vacuum Switch (EGR-EFE-EMR-DTVS)

When engine coolant temperature is below the calibration value of the switch, the EFE valve actuator and the EMR vacuum switch receive manifold vacuum from port 2, which is directed through the TVS from port 1. Port 3 is vented through port 6 while ported vacuum at port 4 and the distributor ports are sealed.
When engine coolant temperature is above the switching point, distributor port 5 receives vacuum from port 1; the EFE actuator and the EMR vacuum switch are vented at port 6; while port 3 receives ported vacuum from port 4.