Machine control system having hydraulic warmup procedure

A method of warming a machine control system, comprising:

• pressurizing a fluid with a pump;
• directing pressurized fluid to an actuator;
• determining a temperature of the fluid;
• determining a pressure of the fluid;
• and
• in response to the sensed temperature, selectively directing pressurized fluid to bypass the actuator, fixing the displacement amount, and comparing the pressure of the fluid of the actuator with a pressure threshold, moving the warmup valve to a flow-blocking position and reducing an outlet pressure of the pump when the pressure of the fluid is greater than the pressure threshold.

A machine, comprising:

• an engine;
• an engine temperature sensor configured to generate an engine temperature signal indicative of a temperature of the engine;
• a pump driven by the engine to pressurize fluid;
• a low pressure reservoir;
• a work tool;
• at least one actuator connected to receive fluid pressurized by the pump and discharge fluid to the low pressure reservoir to move the work tool;
• a valve stack having:
• a supply passage fluidly connected to the pump;
• a drain passage fluidly connected to the drain passage;
• at least one control valve fluidly connected between the supply and the drain passages and being configured to selectively regulate fluid flow to and from the at least one actuator;
• a bypass passage fluidly connecting the supply and drain passages;
• and
• a warmup valve disposed within the bypass passage and being movable between a flow-passing position and a flow-blocking position;
• a hydraulic temperature sensor configured to generate a hydraulic temperature signal indicative of a temperature of the fluid;
• a pressure sensor associated with the at least one actuator and configured to generate a signal indicative of a pressure of the fluid;
• and
• a controller in communication with the engine, the engine temperature sensor, the pump, the warmup valve, and the hydraulic temperature sensor, the controller being configured to move the warmup valve to the flow-passing position, fix a displacement position of the pump, compare the pressure of the fluid of the at least one actuator with a pressure threshold, and move the warmup valve to a flow-blocking position when the pressure of the fluid is greater than the pressure threshold.