Method for diagnosing sticking of lubrication control valve of hybrid vehicle

A method of diagnosing sticking of a lubrication control valve of a hybrid vehicle, the method comprising:

• by a transmission control unit (TCU), determining driving intention of a driver;
• when determined that there is the driver's driving intention, requesting a hybrid control unit (HCU) to diagnose sticking of an independent type lubrication control valve;
• determining, by the HCU, whether or not to permit a sticking diagnosis request of the TCU;
• ordering, by the HCU, pressure to the TCU for operating clutch engagement to an engine clutch, after permitting the sticking diagnosis;
• by the TCU, turning on an electric oil pump which supplies fluid pressure for the engine clutch engagement and controlling an operating speed of the electric oil pump in accordance with pressure order for the engine clutch engagement of the HCU;
• measuring, by an engine clutch pressure sensor, engine clutch engagement pressure in a state in which the engine clutch is engaged by the fluid pressure supplied from the electric oil pump, by measuring first engine clutch engagement pressure in an off-state of the independent type lubrication control valve and second engine clutch engagement pressure in an on-state thereof;
• and
• determining, by the TCU, whether or not the independent type lubrication control valve is stuck, on the basis of a pressure difference between the first engine clutch engagement pressure and the second engine clutch engagement pressure.