In the Allison ATEC/CEC transmission, solenoids are used to do which of the following?

In the Allison ATEC/CEC transmission, solenoids are used to do which of the following?

• A. Send fluid directly to clutches
• B. Control the flow of transmission fluid to valves
• C. Replace the function of the load- and speed-sensing devices
• D. Act as system pressure-modulation devices

Answer: (B)

Solenoids in the Allison ATEC/CEC transmission act as electromechanical actuators that control how hydraulic fluid is directed within the valve body. When the transmission controller sends an electrical signal, a solenoid moves a valve spool, opening or closing passages and changing which circuits receive pressurized fluid. This flow control to the various valves shapes which clutches or bands are engaged and how pressure is applied in different parts of the hydraulic system. They don’t push fluid directly to the clutches, they don’t replace load or speed sensors, and they aren’t standalone system pressure modulators. Their main role is to regulate the flow of transmission fluid to the valve body, enabling the hydraulic control needed for gear shifts.

Solenoids in the Allison ATEC/CEC transmission act as electromechanical actuators that control how hydraulic fluid is directed within the valve body. When the transmission controller sends an electrical signal, a solenoid moves a valve spool, opening or closing passages and changing which circuits receive pressurized fluid. This flow control to the various valves shapes which clutches or bands are engaged and how pressure is applied in different parts of the hydraulic system.

They don’t push fluid directly to the clutches, they don’t replace load or speed sensors, and they aren’t standalone system pressure modulators. Their main role is to regulate the flow of transmission fluid to the valve body, enabling the hydraulic control needed for gear shifts.