DTC P0403: EGR Solenoid Control Circuit: Description

The Exhaust Gas Recirculation (EGR) value consists of a pintle valve which moves by the use of an internal solenoid and an internal position sensor (potentiometer) which used to determine pintle valve position. The ECM controls the solenoid by supplying it ground whenever exhaust gas needs to be recirculated into the intake manifold. When the solenoid is commanded OFF (circuit not grounded), the voltage level at the ECM should be high (ignition voltage). When the solenoid is commanded ON (circuit grounded), the voltage level at the ECM should lower. The ECM EGR solenoid feedback circuit uses a pull-up voltage (2.6-4.6 volts) which allow the ECM to individually differentiate between an open, short to ground or short to voltage. DTC P0403 will set if the ECM detects an open EGR solenoid control circuit when EGR solenoid is commanded Off with engine cranking/running.