Grand Cherokee 4WD V8-4.7L Flex Fuel (2009)
Accumulator: Description and Operation
Valve Body - Operation
OPERATION
NOTE: Refer to the Hydraulic Schematics for a visual aid in determining valve location, operation and design.
SOLENOID SWITCH VALVE
The Solenoid Switch Valve (SSV) controls the direction of the transmission fluid when the L/R-TCC solenoid is energized.
The Solenoid Switch Valve controls line pressure from the LR-TCC solenoid. In 1st gear, the SSV will be in the downshifted position, thus directing
fluid to the L/R clutch circuit. In 2nd, 3rd, 4th, and fifth gears, the solenoid switch valve will be in the upshifted position and directs the fluid into the
torque converter clutch (TCC) circuit.
When shifting into 1st gear, a special hydraulic sequence is performed to ensure SSV movement into the downshifted position. The L/R pressure switch
is monitored to confirm SSV movement. If the movement is not confirmed (the L/R pressure switch does not close), 2nd gear is substituted for 1st. A
DTC will be set after three unsuccessful attempts are made to get into 1st gear in one given key start.
MANUAL VALVE
The manual valve is a relay valve. The purpose of the manual valve is to direct fluid to the correct circuit needed for a specific gear or driving range. The
manual valve, as the name implies, is manually operated by the driver with a lever located on the top of the valve body. The valve is connected
mechanically by a cable to the gearshift mechanism. The valve is held in each of its positions by a roller detent spring (2) that engages the rooster comb
of the TRS selector plate (1).
LOW/REVERSE SWITCH VALVE
The low/reverse switch valve allows the low/reverse clutch to be operated by either the LR/CC solenoid or the MS solenoid.
