System and method for controlling pump performance in a transmission

A method of controlling fluid flow through a transmission, comprising:

• providing a controller, a variable displacement pump having an inlet and an outlet, a first circuit, a second circuit, a regulator valve, a pressure switch, a pump control solenoid, and a temperature sensor, the method comprising:
• pumping fluid from the pump into the first circuit to achieve a first fluid pressure in the first circuit;
• detecting when the first fluid pressure in the first circuit reaches a first regulation pressure;
• fluidly actuating the regulator valve from an unregulated position to a regulated position when the first fluid pressure in the first circuit reaches the first regulation pressure;
• pumping fluid into the second circuit to fluidly couple the second circuit with the pump;
• detecting a fluid temperature of the fluid with the temperature sensor;
• communicating the fluid temperature via the temperature sensor to the controller;
• comparing the fluid temperature to a fluid temperature threshold;
• and
• actuating the pump control solenoid by the controller to adjust the fluid temperature if the fluid temperature does not satisfy the fluid temperature threshold.

A method of controlling fluid flow through a transmission, comprising:

• providing a controller, a variable displacement pump having an inlet and an outlet, a first circuit, a second circuit, a third circuit, a first regulator valve, a second regulator valve, a pressure switch, a pump control solenoid, and a temperature sensor, the method comprising:
• pumping fluid from the pump into the first circuit to achieve a first fluid pressure in the first circuit;
• detecting when the first fluid pressure in the first circuit reaches a first regulation pressure;
• fluidly actuating the first regulator valve from an unregulated position to a regulated position when the first fluid pressure in the first circuit reaches the first regulation pressure;
• pumping fluid into the second circuit and the third fluid circuit to fluidly couple the second and third circuits with the pump;
• detecting when the fluid pressure in the third circuit reaches a second regulation pressure;
• fluidly actuating the second regulator valve from an unregulated position to a regulated position when the fluid pressure in the third circuit reaches the second regulation point;
• detecting a fluid temperature of the fluid with the temperature sensor;
• communicating the fluid temperature via the temperature sensor to the controller;
• comparing the fluid temperature to a fluid temperature threshold;
• actuating the pump control solenoid by the controller to adjust pump displacement from a first pump displacement value to a second pump displacement value;
• and
• controlling the fluid temperature by the actuating step until the fluid temperature satisfies the fluid temperature threshold.