In ATEC and CEC systems, which technician is correct about the trimmer regulator valve control and shift softness?

• A. Technician A
• B. Technician B
• C. Both Technician A and Technician B
• D. Neither Technician A nor Technician B

Answer: (B)

Shift softness in ATEC and CEC transmissions comes from how the hydraulic pressure is shaped during a gear change. The trimmer regulator valve is the part the control system uses to trim that pressure, so the clutch packs engage smoothly. When this valve is trimmed correctly, pressure rises and falls gradually through the shift, giving a soft, smooth engagement. If the trimming is off, shifts can feel harsh or slip-reliant. Technician B is correct because the regulator valve control directly determines the pressure profile during a shift, which defines the shift feel. Other statements that attribute softness only to other components miss this crucial trimming role of the regulator valve.