DTC P0811: General Description
When running at 44 mph (70 km/h) or more, the line pressure is supplied to the clutch piston in response to a request for engagement of the over drive clutch from the powertrain control module (PCM) to cause the clutch to be engaged and the input shaft and the over drive gear rotate together to transmit the driving force. The hydraulic pressure to the clutch is supplied from the ATF pump -> regulator valve -> shift valve -> clutch piston. (Failure in the clutch piston in the supply paths above is detected by failure detection of each shift solenoid valve.) The PCM calculates the difference between the input revolution speed (Engine speed) to the over drive clutch and the output revolution speed (Traction motor speed) and detects a malfunction of the hydraulic pressure supply system or the clutch and stores a DTC when the difference in the revolution speed is more than the prescribed value when engagement of the over drive clutch is requested.