ELECTRONIC COMPONENTS (CONT'D)
TORQUE CONVERTER CLUTCH (TCC) SOLENOID
NORMALLY-LOW PRESSURE CONTROL SOLENOID
TCC CONTROL VALVE
TCC REGULATOR VALVESHTL
SHFT SOL 1
The Torque Converter Clutch (TCC) PC Solenoid is
a "normally-low", electronic pressure regulator used
to control the apply and release of the torque
converter clutch based on current flow through its coil
windings. The TCC PC solenoid regulates actuator
feed limit fluid pressure to the TCC regulator valve,
located in the lower valve body, and provides a signal
pressure to shift the TCC control valve, located in the
pump, to the apply position, as shown in Figure 12.
When the TCM determines to apply the TCC, the
TCC PC solenoid is commanded to specific
pressures, dependent on vehicle operating conditions,
resulting in a smooth apply or release of the TCC.
The solenoid's ability to "Ramp" the TCC apply and
release pressures result in a smoother TCC operation.
When vehicle operating conditions are appropriate
to apply the TCC, the TCM increases current flow to
allow the TCC PC solenoid to increase PCS TCC fluid
pressure, to move the TCC control valve to the apply
position, as shown in Figure 12, and move the
TCC regulator valve to the regulating position to
regulate fluid pressure porportional to solenoid
pressure. Release pressure is directed to exhaust, and
regulated apply pressure is directed to the apply
The TCC PC Solenoid is part of the Control
Solenoid Body And TCM Assembly and is not
side of the converter clutch plate/damper assembly.
The TCM then increases the pressure to control a
slippage of 20-80 RPM between the clutch plate and
converter cover. This "Ramping" procedure provides
improved dampening of engine vibrations and allows
the TCC to apply at low engine speeds in 2nd, 3rd, 4th,
5th and 6th gear.
Release of the TCC is achieved by decreasing TCC
solenoid pressure to a level low enough to allow
spring force to move the TCC control valve and TCC
regulating valve to the release position.
There are also some operating conditions that may
prevent or enable TCC apply, such as engine temp,
transmission temperature, brake switch activation.
If the TCM detects that the TCC system is stuck ON
or OFF, a DTC will be activated.
AUTOMATIC TRANSMISSION SERVICE GROUP
Technical Service Information
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