Patent ID: 6024668
Filing Date: 2000-02-15
Classification: F16H,Y10T

Abstract:
An automatic transmission, comprising:a planetary geartrain including at least one planetary gearset, said planetary geartrain including a first friction member selectively engagable in combination with an overrunning clutch for obtaining a first gear ratio and a second friction member selectively engagable in combination with said first friction member for obtaining a second gear ratio lower than said first gear ratio,a temperature sensor for sensing a temperature of oil in said automatic transmission;a transmission controller including extreme cold logic, wherein upon detection of a transmission oil temperature below a predetermined temperature said extreme cold logic is activated wherein said automatic transmission is limited to shifting to the first gear ratio and the second gear ratio wherein said transmission is controlled to operate in said first gear ratio when a vehicle speed is below a predetermined value and said transmission is controlled to operate in said second gear ratio when the vehicle speed exceeds said predetermined value.