DTC P0402: EGR Flow Excessive: Description

Exhaust Gas Recirculation (EGR) solenoid and pintle valve assembly serve to reduce temperature of combustion by introducing non-volitile exhaust gas into combustion chambers. EGR flow check diagnostic runs once per ignition cycle after 3.3 lbs. (1.5 kg.) of air passed through engine. ECM compares MAP sensor reading to a modeled value that it calculates. DTC sets when measured value is more than a calibrated value of modeled value.