Hyundai Repair: speed sensor right front wheel, speed sensors, engine control module ecm

Question
I have a speed sensor on the right front wheel that is not functioning properly.  Normally i understand that these speed sensors monitor abs function, however in this case, the vehicle does not have abs.  I want to know exactly what this sensor does (other than give me a headache by turning on the engine check light)

Answer
Both the engine control module (ECM) and transmission control module (TCM) use the right front wheel speed sensor to determine vehicle speed.  The ECM also uses this sensor to determine when to activate misfire monitoring.  Since your ECM and TCM cannot read the vehicle speed, the ECM has illuminated your check engine lamp.