Control method for a motor vehicle drive unit to increase the richness of the exhaust gas during regeneration of a nitrogen oxide trap

摘要

IC engine (12) has an exhaust gas recirculation pipe (30) linking the exhaust (16) to the intake (14) placed before the nitrogen oxide trap (28). Motopropulsion group command (10) regulates the air intake (40,42) depending on a threshold value of intake air flow during the trap regeneration phase and the amount of exhaust air recirculated (36,38) depending on a threshold value of intake air flow on normal working conditions.