EGR Thermal Vacuum Switch (EGR-TVS)

PURPOSE
Controls activation of the EGR valve depending on temperature.

OPERATION
When engine coolant temperature is below the calibration point of the thermal vacuum switch, the TVS blocks ported vacuum from reaching the EGR valve.

When engine coolant temperature is at or above the calibration point, ported vacuum is directed from the TVS to the valve--for effective EGR operation.