When the fluid in an Allison ATEC/CEC transmission is extremely cold, below -25 degrees Fahrenheit, the transmission controller allows which of the following?

When the fluid in an Allison ATEC/CEC transmission is extremely cold, below -25 degrees Fahrenheit, the transmission controller allows which of the following?

• A. All range shifts to occur
• B. Shifts from neutral to first or reverse only
• C. Weather does not affect the transmission shifts.
• D. No shifting

Answer: (D)

When the transmission fluid is extremely cold, the hydraulic system becomes much less responsive because the oil’s viscosity is very high. To protect the clutches, gears, and hydraulic circuits from damage or excessive wear, the controller engages a cold-weather protection strategy and withholds shifts. This means the transmission stays in the current gear until the fluid warms enough for normal hydraulic pressure to develop. So at those temperatures, no shifting occurs until the oil temperature rises to a safe level, after which usual shifting can resume.

When the transmission fluid is extremely cold, the hydraulic system becomes much less responsive because the oil’s viscosity is very high. To protect the clutches, gears, and hydraulic circuits from damage or excessive wear, the controller engages a cold-weather protection strategy and withholds shifts. This means the transmission stays in the current gear until the fluid warms enough for normal hydraulic pressure to develop. So at those temperatures, no shifting occurs until the oil temperature rises to a safe level, after which usual shifting can resume.