Circuit Description

The DTC P0443 EVAP System - Purge Solenoid Control Circuit diagnostic monitors the control circuit voltage of the EVAP canister purge valve. Ignition voltage is supplied directly to the EVAP canister purge valve solenoid. The Powertrain Control Module (PCM) supplies a ground path to the solenoid control circuit using an internal solid state device called a driver. The purge valve driver has a fault line that is monitored by the PCM. If the fault detection circuit senses a voltage other than what is expected, this DTC will set.

The PCM will monitor the solenoid control circuit for short to ground, short to voltage, open circuit, open solenoid, or internally shorted or excessively low resistance solenoid coil.