PUMP-OIL
DESCRIPTION
The oil pump is located in the pump housing inside
the bell housing of the transmission case. The oil
pump assembly consists of an inner (3) and outer (2)
gear, a housing (1), and a cover that also serves as
the reaction shaft support (6).
OPERATION
As the torque converter rotates, the converter hub rotates the inner and outer gears. As the gears rotate, the clear-
ance between the gear teeth increases in the crescent area, and creates a suction at the inlet side of the pump.
This suction draws fluid through the pump inlet from the oil pan. As the clearance between the gear teeth in the
crescent area decreases, it forces pressurized fluid into the pump outletand to the valve body.
DISASSEMBLY
1. Remove the reaction shaft support bolts.
2. Remove the reaction shaft support (2) from the
pump housing (1).
SENSOR-OUTPUT SPEED
DESCRIPTION
The Input (1) and Output (2) Speed Sensors are two-
wire magnetic pickup devices that generate AC signals
as rotation occurs. They are mounted in the left side
of the transmission case and are considered primary
inputs to the Transmission Control Module (TCM).
OPERATION
The Input Speed Sensor provides information on how fast the input shaft is rotating. As the teeth of the input clutch
hub pass by the sensor coil, an AC voltage is generated and sent to the TCM. The TCM interprets this information
as input shaft rpm.
The Output Speed Sensor generates an AC signal in a similar fashion, thoughitscoilisexcitedbyrotationofthe
rear planetary carrier lugs. The TCM interprets this information as outputshaftrpm.
The TCM compares the input and output speed signals to determine the following:
Transmission gear ratio
Speed ratio error detection
CVI calculation
The TCM also compares the input speed signal and the engine speed signal to determine the following:
Torque converter clutch slippage
Torque converter element speed ratio
REMOVAL
1. Raise vehicle.
2. Place a suitable fluid catch pan under the transmis-
sion.
3. Remove the wiring connector from the output
speed sensor (2).
NOTE: The speed sensor bolt has a sealing patch
applied from the factory. Be sure to reuse the
same bolt.
4. Remove the bolt holding the output speed sensor
to the transmission case.
5. Remove the output speed sensor (2) from the
transmission case.
SEAL-OIL PUMP
REMOVAL
1. Remove the transmission from the vehicle (Refer to 21 - TRANSMISSION/AUTOMATIC - 42RLE - REMOVAL).
2. Remove the torque converter from the transmission bellhousing.
3. Use a screw mounted in a slide hammer to remove oil pump seal.
INSTALLATION
1. Clean and inspect oil pump seal seat. Then install seal using Seal Installer C-4193-A.
2. Clean and inspect torque converter hub. If nicks, scratches or hub wear are found, torque converter replacement
will be required.
CAUTION: If the torque converter isbeing replaced, apply a light coating of grease to the crankshaft pilot
hole. Also inspect the engine drive plate for cracks. If any cracks are found replace the drive plate. Do not
attempt to repair a cracked drive plate. Always use new torque converter todrive plate bolts.
3. Apply a light film of transmission oil to the torque converter hub and oilseal lips. Then install torque converter
into transmission. Be sure that the hub lugs mesh with the front pump lugs when installing.
4. Reinstall the transmission into the vehicle. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE -
INSTALLATION)
SOLENOID-PRESSURE CONTROL
DESCRIPTION
Thepressurecontrolsolenoid(1)ismountedonthe
top of the valve body, next to the line pressure sensor
(2).
The TCM utilizes a closed-loop system to control
transmission line pressure. The system contains a
variable force style solenoid, the Pressure Control
Solenoid. The solenoid is duty cycle controlled by the
TCM to vent the unnecessary line pressure supplied
by the oil pump back to the sump. The system also
contains a variable pressure style sensor, the Line
Pressure Sensor, which is a direct input to the TCM.
The line pressure solenoid monitors the transmission
line pressure and completes the feedback loop to the
TCM. The TCM uses this information to adjust its con-
trol of the pressure control solenoid to achieve the
desired line pressure.
OPERATION
The pressure control solenoid (PCS) is a variable force (VFS) style solenoid. A VFS solenoid is an electro-hydraulic
actuator, combining a solenoid and a regulating valve.
The transmission control module varies the current for the PCS, which variesthepressureinthelinepressure
hydraulic circuit. When the current (duty cycle) of the PCS is low, the pressure in the circuit is higher. At 0 current
(0% duty cycle), the pressure is at the maximum value. Conversely, when thecurrent is maximized (100% duty
cycle), the pressure in the circuit is at the lowest possible value.
REMOVAL
1. Remove the valve body from the transmission.
(Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE/VALVE BODY - REMOVAL)
2. Remove the electrical connectors from the pres-
sure control solenoid (1) and the line pressure sen-
sor (2).
3. Remove the screws (6) holding the pressure con-
trol solenoid (1) and line pressure sensor (2) to the
valve body.
4. Remove the pressure control solenoid and line
pressure sensor from the valve body.
SOLENOID
DESCRIPTION
The typical electrical solenoid used in automotive applications is a linear actuator. It is a device that produces
motion in a straight line. This straight line motion can be either forward or backward in direction, and short or long
distance.
A solenoid is an electromechanical device that uses a magnetic force to perform work. It consists of a coil of wire,
wrapped around a magnetic core made from steel or iron, and a spring loaded,movable plunger, which performs
the work, or straight line motion.
The solenoids used in transmission applications are
attached to valves which can be classified asnor-
mally openornormally closed.Thenormally open
solenoid valve is defined as a valve which allows
hydraulic flow when no current or voltage is applied to
the solenoid. Thenormally closedsolenoid valve is
defined as a valve which does not allow hydraulic flow
when no current or voltage is applied to the solenoid.
These valves perform hydraulic control functions for
the transmission and must therefore be durable and
tolerant of dirt particles. For these reasons, the valves
have hardened steel poppets and ball valves. The
solenoids operate the valves directly, which means
that the solenoids must have very high outputs to
close the valves against the sizable flow areas and
line pressures found in current transmissions. Fast
response time is also necessary to ensure accurate
control of the transmission.
The strength of the magnetic field is the primary force
that determines the speed of operation in a particular
solenoid design. A stronger magnetic field will cause
the plunger to move at a greater speed than a weaker
one. There are basically two ways to increase the
force of the magnetic field:
1. Increase the amount of current applied to the
coil or
2. Increase the number of turns of wire in the coil.
The most common practice is to increase the number
of turns by using thin wire that can completely fill the
available space within the solenoid housing. The
strength of the spring and the length of the plunger
also contribute to the response speed possible by a
particular solenoid design.
A solenoid can also be described by the method by
which it is controlled. Some of the possibilities include
variable force, pulse-width modulated, constant ON, or
duty cycle. The variable force and pulse-width modu-
lated versions utilize similar methods to control the
current flow through the solenoid to position the sole-
noid plunger at a desired position somewhere
between full ON and full OFF. The constant ON and
duty cycled versions control the voltage across the
1 - MANUAL VALVE
2 - LINE PRESSURE
3 - 2/4 - LOW REVERSE SOLENOID ENERGIZED
4 - UNDERDRIVE SOLENOID DE-ENERGIZED
5 - UNDERDRIVE CLUTCH
1-OVERDRIVECLUTCH
2 - NO VENT
3 - OVERDRIVE SOLENOID ENERGIZED
4 - MANUAL VALVE
5 - LOW REVERSE/CONVERTER CLUTCH SOLENOID DE-
ENERGIZED
6-SOLENOIDSWITCHVALVE
7 - TAPER
8 - VENT TO SUMP
9 - ORIFICE
10 - CHECK BALL
CONVERTER-TORQUE
DESCRIPTION
The torque converter is a hydraulic device that cou-
ples the engine crankshaft to the transmission. The
torque converter consists of an outer shell with an
internal turbine (1), a stator (4), an overrunning clutch,
an impeller (2) and an electronically applied converter
clutch (6). The converterclutch provides reduced
engine speed and greater fuel economy when
engaged. Clutch engagement also provides reduced
transmission fluid temperatures. The torque converter
hub drives the transmission oil (fluid) pump.
The torque converter is a sealed, welded unit that is
not repairable and is serviced as an assembly.
CAUTION: The torque converter must be replaced
if a transmission failure resulted in large amounts
of metal or fiber contamination in the fluid.
IMPELLER
The impeller is an integral part of the converter housing. The impeller consists of curved blades placed radially
along the inside of the housing on the transmission side of the converter. As the converter housing is rotated by the
engine, so is the impeller, because they are one and the same and are the driving members of the system.
Impeller
1 - ENGINE FLEXPLATE 4 - ENGINE ROTATION
2 - OIL FLOW FROM IMPELLER SECTION INTO TURBINE
SECTION5 - ENGINE ROTATION
3 - IMPELLER VANES AND COVER ARE INTEGRAL
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 (if appicable) gear ranges depending on over-
drive control switch position. If the overdrive control
switch is in the normal ON position, the clutch will
engage after the shift to fourth gear. If the control
switch is in the OFF position, the clutch will engage
after the shift to third gear.
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 L/R-CC
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 L/R 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 L/R Solenoid (duty cycle) to obtain partial torque converter clutch application.
Partial EMCC operation is maintaineduntil 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.
FULL EMCC
During Full EMCC operation, the TCM increases the L/R Solenoid duty cycle to full ON after Partial EMCC control
brings the engine speed within the desired slip range of transmission input speed relative to engine rpm.
GRADUAL-TO-NO EMCC
This operation is to soften the change from Full or Partial EMCC to No EMCC. This is done at mid-throttle by
decreasing the L/R Solenoid duty cycle.
REMOVAL
1. Remove transmission and torque converter from vehicle. (Refer to 21 - TRANSMISSION/AUTOMATIC - 45RFE/
545RFE - REMOVAL)
2. Place a suitable drain pan under the converter housing end of the transmission.
CAUTION: Verify that transmission is secure on the lifting device or work surface, the center of gravity of
the transmission will shift when the torque converter is removed creatingan unstable condition. The torque
converter is a heavy unit. Use caution when separating the torque converter from the transmission.
3. Pull the torque converter forward until the center hub clears the oil pumpseal.
Stator Operation
1 - DIRECTION STATOR WILL FREE WHEEL DUE TO OIL
PUSHING ON BACKSIDE OF VANES
2-FRONTOFENGINE
3 - INCREASED ANGLE AS OIL STRIKES VANES
4 - DIRECTION STATOR IS LOCKED UP DUE TO OIL PUSHING
AGAINST STATOR VANES