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Home >> GMC >> 1999 >> Safari Van AWD V6-4.3L VIN W >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Scan Tool Testing and Procedures >> Scan Tool Data, Normal Values and Definitions >> Scan Tool Data Definitions - Powertrain Systems >> EVAP Duty Cycle
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EVAP Duty Cycle

Range 0 - 100%
The scan tool indicates the [1][2]EVAP duty cycle that the VCM is commanding. The EVAP duty cycle is a pulse width modulated voltage applied to the purge valve which is displayed as a percentage. A high percentage of EVAP duty cycle would indicate near maximum canister purging.
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