EGR modules electronically control Exhaust Gas Recirculation (EGR) valve operation, optimizing emissions and engine performance. These units are typically mounted near the intake manifold or EGR valve itself, receiving data from engine sensors like engine speed, load, and temperature. Functionality includes precise valve lift control via PWM signals and diagnostic capabilities reporting valve position and system faults. Modern EGR modules often incorporate proportional control for finer adjustments and may feature integrated position sensors for closed-loop feedback. Failures commonly manifest as drivability issues, increased emissions, or diagnostic trouble codes related to EGR system performance.