Chrysler 2005 Crossfire SRT6 Service Manual page 3417

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STATOR
Torque multiplication is achieved by locking the sta-
tor's over-running clutch to its shaft. Under stall condi-
tions (the turbine is stationary), the oil leaving the
turbine blades strikes the face of the stator blades and
tries to rotate them in a counterclockwise direction (3).
When this happens the over-running clutch of the sta-
tor locks and holds the stator from rotating. With the
stator locked, the oil strikes the stator blades and is
redirected into a "helping" direction before it enters the
impeller. This circulation of oil from impeller to turbine,
turbine to stator, and stator to impeller, can produce a
maximum torque multiplication of about 2.0:1. As the
turbine begins to match the speed of the impeller, the
fluid that was hitting the stator in such as way as to
cause it to lock-up is no longer doing so. In this con-
dition of operation, the stator begins to free wheel and
the converter acts as a fluid coupling.
TORQUE CONVERTER CLUTCH (TCC)
In a standard torque converter, the impeller and tur-
bine are rotating at about the same speed and the
stator is freewheeling, providing no torque multiplica-
tion. By applying the turbine's piston and friction mate-
rial to the front cover, a total converter engagement
can be obtained. The result of this engagement is a
direct 1:1 mechanical link between the engine and the
transmission.
The clutch can be engaged in second, third, fourth,
and fifth gear ranges.
The TCM controls the torque converter by way of
internal logic software. The programming of the soft-
ware provides the TCM with control over the torque
converter solenoid. There are four output logic states
that can be applied as follows:
• No EMCC
• Partial EMCC
• Full EMCC
• Gradual-to-no EMCC
NO EMCC
Under No EMCC conditions, the TCC Solenoid is OFF. There are several conditions that can result in NO EMCC
operations. No EMCC can be initiated due to a fault in the transmission or because the TCM does not see the need
for EMCC under current driving conditions.
PARTIAL EMCC
Partial EMCC operation modulates the TCC Solenoid (duty cycle) to obtain partial torque converter clutch applica-
tion. Partial EMCC operation is maintained until Full EMCC is called for and actuated. During Partial EMCC some
slip does occur. Partial EMCC will usually occur at low speeds, low load and light throttle situations.
AUTOMATIC - NAG1 SERVICE INFORMATION 21 - 347