Systems and methods for controlling transmission valves in a marine propulsion device

A transmission for a marine propulsion device, the transmission comprising:

• a valve and a gear that is selectively engageable by the valve to generate propulsion for the marine propulsion device, wherein the engagement of the gear is controlled by controlling a current supplied to the valve;
• a memory module that stores first, second, and third currents for supplying current to the valve, and first and second wait times for controlling the current supplied to the valve, wherein the first and second wait times are non-zero;
• a processing module operatively coupled to the memory module and the valve and configured to:
• receive a request to disengage the gear and to subsequently reduce the current supplied to the valve from a starting current to the first current;
• count a first elapsed time since the valve was reduced to the first current;
• compare the first elapsed time to the first wait time and to increase the current supplied to the valve to the second current once the first elapsed time exceeds the first wait time;
• count a second elapsed time since the valve was increased to the second current;
• compare the second elapsed time to the second wait time and to reduce the current supplied to the valve to the third current once the second elapsed time exceeds the second wait time;
• wherein the valve is closed when the current supplied to the valve is the third current.

A method for controlling a valve to disengage a gear in a transmission for a marine propulsion device, the method comprising:

• reducing, after receiving a request to disengage the gear, a current supplied to the valve from a starting current to a first current, wherein the first current is less than 50% of the starting current and also greater than zero;
• counting a first elapsed time since the valve was reduced to the first current;
• comparing the first elapsed time to a first wait time that is between 5 and 900 ms;
• increasing the current supplied to the valve to a second current once the first elapsed time is determined to exceed the first wait time;
• counting a second elapsed time since the valve was increased to the second current;
• comparing the second elapsed time to a second wait time greater than zero seconds;
• and
• reducing the current supplied to the valve to a third current once the second elapsed time is determined to exceed the second wait time;
• wherein the valve is closed when the current supplied to the valve is the third current.