Abstract: An object of the present invention is, even if an abnormality occurs in an oil pressure circuit of an automatic transmission, to avoid traveling performance deterioration by the abnormality when gear change is performed. The present invention provides a control device of an automatic transmission and a method of controlling the automatic transmission, each of which switches from a normal state to an abnormality diagnosis state at a predetermined change gear ratio to diagnose whether there is an abnormality in an automatic transmission, the normal state being a state where an oil pressure supply portion supplies oil pressure to a predetermined friction engaging element, the abnormality diagnosis state being a state where an abnormality diagnosis oil pressure supply portion including an oil pressure supply passage different from an oil pressure supply passage of the oil pressure supply portion supplies the oil pressure to the predetermined friction engaging element.

Abstract: A hydraulic control circuit includes: a shift valve configured to be switched between a state of supplying oil pressure to a clearance adjusting chamber of an LR brake and a state of discharging the oil pressure from the clearance adjusting chamber of the LR brake; and a linear SV configured to control the oil pressure supplied to a pressing chamber of the LR brake. The hydraulic control circuit further includes a source pressure oil passage through which oil pressure equal to the oil pressure supplied from the shift valve to the clearance adjusting chamber is supplied to a source pressure port a of the linear SV. By discharging the oil pressure in the clearance adjusting chamber at the time of opening malfunction of the linear SV, the oil pressure in the pressing chamber is also discharged through a drain port of the shift valve.

Abstract: An object of the present invention is, even if an abnormality occurs in an oil pressure circuit of an automatic transmission, to avoid a case where a traveling performance deterioration by the abnormality when gear change is performed. The present invention provides a control device of an automatic transmission and a method of controlling the automatic transmission, each of which switches from a normal state to an abnormality diagnosis state at a predetermined change gear ratio to diagnose whether there is an abnormality in an automatic transmission, the normal state being a state where an oil pressure supply portion supplies oil pressure to a predetermined friction engaging element, the abnormality diagnosis state being a state where an abnormality diagnosis oil pressure supply portion including an oil pressure supply passage different from an oil pressure supply passage of the oil pressure supply portion supplies the oil pressure to the predetermined friction engaging element.

Abstract: A hydraulic control circuit includes: a shift valve configured to be switched between a state of supplying oil pressure to a clearance adjusting chamber of an LR brake and a state of discharging the oil pressure from the clearance adjusting chamber of the LR brake; and a linear SV configured to control the oil pressure supplied to a pressing chamber of the LR brake. The hydraulic control circuit further includes a source pressure oil passage through which oil pressure equal to the oil pressure supplied from the shift valve to the clearance adjusting chamber is supplied to a source pressure port a of the linear SV. By discharging the oil pressure in the clearance adjusting chamber at the time of opening malfunction of the linear SV, the oil pressure in the pressing chamber is also discharged through a drain port of the shift valve.

Abstract: A vehicle idle stop system is disclosed. The idle stop system comprises an engine, an automatic transmission, a first oil pump driven by said engine and generating hydraulic pressure which is supplied to a friction element of said automatic transmission, a second oil pump capable of operating and generating hydraulic pressure which is supplied to a friction element of said automatic transmission during an engine stop, and a controller. The controller is configured to control the engine to stop when a predetermined engine stop condition is satisfied, and to control the second oil pump to supply hydraulic pressure to a predetermined friction element coupled to a forward starting gear of the automatic transmission, the hydraulic pressure supplied to couple the predetermined friction element when the engine is automatically stopped and when a gear range of the automatic transmission is in a neutral range.

Abstract: A vehicle idle stop system is disclosed. The idle stop system comprises an engine, an automatic transmission, a first oil pump driven by said engine and generating hydraulic pressure which is supplied to a friction element of said automatic transmission, a second oil pump capable of operating and generating hydraulic pressure which is supplied to a friction element of said automatic transmission during an engine stop, and a controller. The controller is configured to control the engine to stop when a predetermined engine stop condition is satisfied, and to control the second oil pump to supply hydraulic pressure to a predetermined friction element coupled to a forward starting gear of the automatic transmission, the hydraulic pressure supplied to couple the predetermined friction element when the engine is automatically stopped and when a gear range of the automatic transmission is in a neutral range.