Circuit Description

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

Shift valve D is incorporated into the control circuit inside the transmission. When the shift lever is in D or I range, line pressure is supplied to shift valve D, and clutch control pressure A is supplied to the 4th clutch. When the shift lever is in L range, the shift valve D is pushed by the spring D and the clutch control pressure B is supplied to the L/H clutch. Shift valve D operates upon rise in the line pressure or clutch control pressure A. Shift valve D is pushed back by the reactive force of spring D when the line pressure or clutch control pressure A drops. The PCM monitors mainshaft to output shaft speed ratio in the gear positions determined by the shift schedule.

When the PCM detects an incorrect ratio for the commanded gear, DTC P0780 sets. DTC P0780 is a type B DTC.