A control valve assembly includes a body having a first mud flow passage defining a mud flow inlet and one or more second mud flow passage portions. A magnetic plunger is slidingly mounted within the body. The magnetic plunger includes one or more third mud flow passage portions each including an inlet section and an outlet section configured to selectively align with the one or more second mud flow passage portions. A solenoid is mounted at the body. The solenoid is selectively activated to shift the magnetic plunger between a first position wherein the third mud flow passage portion is misaligned with the one or more second mudflow passage portions and a second position wherein the third mud flow passage portion aligns with the one or more second mud flow passage portions allowing a pulse of mud to flow through the mud flow passage.