Missing return control from ECU to emmission canaster vent valve. on 2003 Volkswagen EuroVan

Looks like a solid state driver because with the vent valve electrical connection disconnected I originally could read a +3.5 bias voltage which looks like a base to collector voltage without an emmiter groung return indicating a faulty transistor. Is the control driver internal or external to the ECU?

Asked by for the 2003 Volkswagen EuroVan