Technician A says that most current highway diesel engines use the engine ECM to master control of engine braking cycles. Technician B says that some current trucks option engine braking as part of cruise control and directional stability management. Who is correct?

The response indicating that both technicians are correct highlights the advanced functionalities integrated into modern highway diesel engines. The engine ECM (Electronic Control Module) plays a pivotal role in managing the various systems of the engine, including engine braking. This control is crucial because it enables the engine to effectively manage the vehicle's speed and deceleration, particularly on downhill grades, by utilizing engine braking rather than relying solely on the traditional brake system.

Additionally, the incorporation of engine braking into cruise control settings and directional stability management enhances vehicle safety and efficiency. By utilizing engine braking as part of these systems, trucks can maintain a steady speed while descending hills or when deceleration is necessary, thereby reducing wear on conventional brakes and optimizing fuel consumption.

These advanced features reflect the sophisticated design and integration of electronic controls in contemporary diesel engines, confirming the accuracy of both technicians' statements.