DTC P0443: EVAP Purge Solenoid Control Circuit: Description
WARNING: This page is about a different car, the 2002 Pontiac Montana, 2002 Oldsmobile Silhouette, and 2002 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.
The Evaporative (EVAP) emission purge valve is pulse width modulated (PWM). The Powertrain Control Module (PCM) controls the EVAP purge valve duty cycle by controlling the amount of purge valve ON time. The scan tool displays the amount of ON time as a percentage. An ignition voltage is supplied directly to the EVAP purge valve. The PCM controls the EVAP purge valve by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the controlled component. The PCM monitors the status of the driver. If the PCM detects an incorrect voltage for the commanded state of the driver, DTC P0443 sets.