3-2 Control Solenoid Valve and 3-2 Control Valve
WARNING: This page is about a different car, the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
These components are used to increase the exhaust rate of 3rd accumulator fluid, as needed, depending on the vehicle speed.
The 3-2 control solenoid valve is a normally closed On/Off solenoid controlled by the PCM. The PCM controls the solenoid state during a 3-2 downshift according to vehicle speed.
Low Speed
- At lower vehicle speeds, the PCM operates the 3-2 control solenoid valve in the Off position.
- In the Off position the solenoid blocks actuator feed limit fluid pressure from the 3-2 control valve.
- With no actuator feed limit fluid pressure, the 3-2 control valve spring force keeps the valve open to allow a faster exhaust of 3rd accumulator fluid through orifice #14 into the 3-4 clutch fluid circuit.
- A faster exhaust of the 3rd accumulator exhaust fluid provides a faster apply of the 2-4 band, as needed at lower vehicle speeds.
High Speed
- At high vehicle speed, the PCM operates the 3-2 control solenoid valve in the On position allowing actuator feed limit fluid to pass through the solenoid. This pushes the 3-2 control valve into the closed position.
- This action permits a slow apply of the 2-4 band by blocking off 3rd accumulator exhaust fluid from entering the 3-4 clutch fluid circuit through orifice #14.
- This allows the engine speed to easily come up to the necessary RPM before the 2-4 band is applied.