GM Service Manual Online
For 1990-2009 cars only

When the transmission is operating in EVT Mode Low (D), and the HPCM determines that operating conditions are appropriate, the internal combustion engine is turned OFF, the auxiliary fluid pump is turned ON, and the TCM commands the following changes to the transmission's hydraulic and electrical systems:

Pressure Regulation

Pressure Control (PC) Solenoid 5

The PC solenoid 5 is energized (ON) allowing actuator feed limit fluid to enter the PCS 5 signal circuit. PCS 5 signal fluid is then routed through orifice #41 to the auxiliary line boost valve.

Auxiliary Line Boost Valve

PCS 5 signal fluid, at the auxiliary line boost valve, opposes auxiliary line boost valve spring force and orificed auxiliary line boost fluid pressure to regulate line or auxiliary line pressure into the auxiliary line boost circuit. Auxiliary line boost fluid is routed to the fluid pump and auxiliary fluid pump valve in order to regulate auxiliary line fluid pressure.

Line Pressure Control (PC) Solenoid

The line PC solenoid is de-energized (OFF) allowing PCS line fluid pressure to exhaust through the solenoid.

Hybrid Low, 1-2 Clutch Remains Applied

Hybrid Low, 1-2 Clutch Assembly

With the exception of the switch to auxiliary line fluid pressure from the auxiliary fluid pump, no other changes occur to the transmission's hydraulic system and the hybrid low, 1-2 clutch remains applied.

EVT Mode Low - Engine Off/Auto Stop


Object Number: 1968878  Size: FS