Page 54 - Hydra-matic 6 Speed RWD Technician's Guide (October 2005)

ELECTRICAL COMPONENTS

Torque Converter Clutch Pressure Control (TCC PC) Solenoid:
The TCC PC solenoid is a normally-low, precision electronic
pressure regulator used to control the apply and release of the
converter clutch based on current flow through its coil
windings. The TCC PC solenoid is located in the control CONTROL COIL
PRESSURE
solenoid (w/body and TCM) valve assembly and is not ASSEMBLY HOUSING
serviced separately. The TCC PC solenoid regulates actuator SUPPLY
PRESSURE EXHAUST
feed limit fluid pressure to the TCC regulator valve located (ACTUATOR
in the lower valve body and provides a signal pressure to FEED LIMIT)
shift the TCC control valve, located in the pump, to the apply
position. 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 results in a CLOSED END
FEATURE O-RING
smoother TCC operation. VARIABLE
RESTRICTION
When vehicle operating conditions are appropriate to apply
CONNECTOR
the TCC, the TCM increases the current flow to allow the
TCC PC solenoid to direct PCS TCC fluid pressure to move NORMALLY-LOW PRESSURE CONTROL SOLENOID
the TCC control valve to the apply position and move the
TCC regulator valve to the regulating position to regulate
fluid pressure proportional to TCC PC solenoid pressure.
Release pressure is directed to exhaust, and regulated apply
fluid is directed to the apply side of the converter pressure
plate/damper assembly. The TCM then increases the pressure
There are also some operating conditions that may prevent or
to control a slippage of 20–80 RPM between the pressure
plate/damper assembly and the converter cover. This provides enable TCC apply such as: engine temperature, transmission
temperature, brake switch activation.
for improved dampening of engine vibrations and allows the
TCC to apply at low engine speeds in 2nd, 3rd, 4th, 5th and
6th gear. The TCC PC solenoid is commanded to maximum The TCC PC solenoid is the only electronic control component
pressure to fully apply the pressure plate/damper assembly. of the TCC apply and release system. Other components are
hydraulic control or regulating valves. The illustration below
Release of the TCC is achieved by decreasing TCC PC
shows the valves and the TCC PC solenoid that comprise the
solenoid pressure to a level low enough to allow spring force TCC control system. (For more information on TCC system
to move the TCC control valve and the TCC regulator valve
operation see page 14 & 15).
to the release position. TCC apply fluid is then directed to
the cooler and converter feed limit fluid is directed into the
release circuit, to the release side of the pressure plate/damper If the TCM detects that the TCC system is stuck ON or
assembly. This fluid then flows into the apply side of the
stuck OFF, a DTC will be activated.
pressure plate/damper assembly and out of the converter
through the apply circuit to the TCC control valve.

ACT FD LIM

ACT FD LIM

TCC PCS TCC
CONV FD LIMIT SOLENOID DRIVE 1-6
PRESSURE
CONTROL
N.L.
ON
7 9
EXH PCS TCC SHTL TCC REGULATOR VALVE
TCC REL 10 EX EX 11
➤
SOL 1 REG APP REG APP
TCC CONTROL VALVE REG APP
COOLER FD
TCC APPLY
PCS TCC

Figure 41 45