DTC P0403: EGR Solenoid Control Circuit: Description

The Engine Control Module (ECM) controls the Exhaust Gas Recirculation (EGR) valve with a solid state device called a driver. The driver supplies the EGR solenoid with a ground that is Pulse Width Modulated (PWM) through the EGR solenoid control circuit. 12 volts are provided by the Engine CNTL 1 fuse through the ignition positive voltage circuit. The ECM uses a pull-up voltage of 2.6-4.6 volts to determine if a circuit is open, shorted to ground or shorted to voltage. If the ECM detects a pull-up voltage between 2.6-4.6 volts with the EGR not commanded, indicating an open circuit, DTC P0403 sets.