Ford
Type:
    Powertrain - Auxiliary Emission Controls - ISO/SAE Controlled
Description:
    EVAP System Canister Vent Solenoid Fault Conditions
Cause:
    Engine running, then the PCM detected a fault in the solenoid circuit with the canister vent solenoid energized or de-energized

Generic
Type:
    Powertrain - Auxiliary Emission Controls - ISO/SAE Controlled
Description:
    Evaporative Emission System Vent Control Circuit

GM
Type:
    Powertrain - Auxiliary Emission Controls - ISO/SAE Controlled
Description:
    EVAP Purge Vent Valve Circuit Conditions
Cause:
    Engine speed over 40 rpm, system voltage from 7.5-15v, then the PCM detected a short to ground, an open circuit or a short to power in the Purge control circuit during the test period.