Patent ID: 7747366

Claim:
A method for determining an estimated transmission oil sump temperature of a manual transmission of a vehicle, the method comprising the steps of: (a) obtaining an initial transmission oil sump temperature; (b) determining a heat input to the manual transmission based on vehicle operating parameters, including determining in which one of a plurality of gears the manual transmission is operating; calculating a mechanical inefficiency value for the one gear by solving the equation IEFF=(C1+C2*|ENGTRQACT|+C3*ENGSPD*e.sup.(−C4*Ts))/|ENGTRQACT|, where IEFF is the mechanical inefficiency value, |ENGTRQACT| is an absolute value of a torque being produced by an engine, ENGSPD is a rotational speed of the engine, Ts is a current value of the estimated transmission oil sump temperature, and C1, C2, C3 and C4 are constants that are based in part on the one gear in which the manual transmission is operating; the heat input to the manual transmission being determined by (|ENGTRQACT|*ENGSPD*(2.pi./60)*IEFF; (c) determining a heat loss from the manual transmission based on the vehicle operating parameters; (d) adding the heat input to and subtracting the heat loss from the initial transmission oil sump temperature to obtain the estimated transmission oil sump temperature; (e) storing the estimated transmission oil sump temperature in an electronic control module of the vehicle; (f) determining if the estimated transmission oil sump temperature is greater than a first transmission heat threshold; and (g) entering a transmission protection mode if the estimated transmission oil sump temperature is greater than the first transmission heat threshold.