Self-Study Program

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367_067
Hydraulic control
Valve assembly
The clutches and brakes (shift elements) are
controlled by the valve assembly by means of
hydraulic shift control valves (so-called gate valves).
The gate valves are controlled by electromagnetic
valves, which, in turn, are activated by the
automatic gearbox control unit J217.
In addition to the shift elements, the valve assembly
controls the lockup clutch and the various pressures
throughout the gearbox (e.g. main pressure, control
pressure, torque converter pressure, lubricating
pressure etc.). The valve assembly is largely
responsible for oil supply and therefore for proper
functioning of the gearbox.
The valve assembly comprises the following
components:
– the mechanically actuated selector valve
– the hydraulic shift control valves
– two electrically controlled shift solenoids
(3/2-way valves)
– six electronic pressure control valves
(modulating valves) and
– the gearbox oil temperature sensor
N93 N90 N92
N283 N282
N88
Shift solenoids
OPEN-CLOSE valves
Gearbox oil temperature sensor
N89N91
G93
Electronic pressure control valves (EPCV)
Selector valve
Oil intake port
Bottom view of valve assembly
to/from gearbox
control unit J217
Connection to gearbox input speed sender G182 Connection to gearbox output speed sender G195
Gearbox subassemblies