(3) Install steering column lower shroud.
(4) Install knee bolster (Fig. 274).
(5) Install instrument panel lower silencer (Fig.
275).
(6) Connect battery negative cable.
(7) Verify proper shift interlock system operation.
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 31TH/SHIFT INTERLOCK SOLENOID -
OPERATION)
SOLENOID/PRESSURE
SWITCH ASSY
DESCRIPTION
The Solenoid/Pressure Switch Assembly (Fig. 276)
is external to the transaxle and mounted to the transaxle case. The assembly consists of four sole-
noids that control hydraulic pressure to the LR/CC,
2/4, OD, and UD friction elements. The reverse
clutch is controlled by line pressure from the manual
valve in the valve body. The solenoids are contained
within the Solenoid/Pressure Switch Assembly, and
can only be serviced by replacing the assembly.
The solenoid assembly also contains pressure
switches that monitor and send hydraulic circuit
information to the PCM/TCM. Likewise, the pressure
switches can only be service by replacing the assem-
bly.
OPERATION
SOLENOIDS
The solenoids receive electrical power from the
Transmission Control Relay through a single wire.
The PCM/TCM energizes or operates the solenoids
individually by grounding the return wire of the sole-
noid needed. When a solenoid is energized, the sole-
noid valve shifts, and a fluid passage is opened or
closed (vented or applied), depending on its default
operating state. The result is an apply or release of a
frictional element. The 2/4 and UD solenoids are normally applied,
which by design allow fluid to pass through in their
relaxed or ªoffº state. This allows transaxle limp-in
(P,R,N,2) in the event of an electrical failure. The continuity of the solenoids and circuits are
periodically tested. Each solenoid is turned on or off
depending on its current state. An inductive spike
Fig. 274 Knee Bolster
1 - KNEE BOLSTER
Fig. 275 Instrument Panel Lower Silencer
1 - INSTRUMENT PANEL LOWER SILENCER
Fig. 276 Solenoid/Pressure Switch Assembly
1 - SOLENOID AND PRESSURE SWITCH ASSEMBLY
RS 40TE AUTOMATIC TRANSAXLE21s - 137
SHIFT INTERLOCK SOLENOID (Continued)
should be detected by the PCM/TCM during this test.
It no spike is detected, the circuit is tested again to
verify the failure. In addition to the periodic testing,
the solenoid circuits are tested if a speed ratio or
pressure switch error occurs.
PRESSURE SWITCHES
The PCM/TCM relies on three pressure switches to
monitor fluid pressure in the L/R, 2/4, and OD
hydraulic circuits. The primary purpose of these
switches is to help the PCM/TCM detect when clutch
circuit hydraulic failures occur. The range for the
pressure switch closing and opening points is 11-23
psi. Typically the switch opening point will be
approximately one psi lower than the closing point.
For example, a switch may close at 18 psi and open
at 17 psi. The switches are continuously monitored
by the PCM/TCM for the correct states (open or
closed) in each gear as shown in the following chart:
PRESSURE SWITCH STATES
GEAR L/R 2/4 OD
ROPOPOP
P/N CL OP OP 1st CL OP OP
2nd OP CL OP DOPOPCL
OD OP CL CL OP = OPEN
CL = CLOSED
A Diagnostic Trouble Code (DTC) will set if the
PCM/TCM senses any switch open or closed at the
wrong time in a given gear. The PCM/TCM also tests the 2/4 and OD pressure
switches when they are normally off (OD and 2/4 are
tested in 1st gear, OD in 2nd gear, and 2/4 in 3rd
gear). The test simply verifies that they are opera-
tional, by looking for a closed state when the corre-
sponding element is applied. Immediately after a
shift into 1st, 2nd, or 3rd gear with the engine speed
above 1000 rpm, the PCM/TCM momentarily turns
on element pressure to the 2/4 and/or OD clutch cir-
cuits to identify that the appropriate switch has
closed. If it doesn't close, it is tested again. If the
switch fails to close the second time, the appropriate
Diagnostic Trouble Code (DTC) will set.
REMOVAL
NOTE: If solenoid/pressure switch assembly is
being replaced, it is necessary to perform the TCM
Quick Learn Procedure. (Refer t o 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/TRANSMISSION
CONTROL MODULE - STANDARD PROCEDURE)
(1) Disconnect battery negative cable.
(2) Remove air cleaner assembly.
(3) Disconnect solenoid/pressure switch assembly
connector (Fig. 277). (4) Disconnect input speed sensor connector (Fig.
277).
Fig. 277 Transmission Connectors
1 - SOLENOID PACK CONNECTOR
2 - INPUT SPEED SENSOR CONNECTOR
3 - OUTPUT SPEED SENSOR CONNECTOR
4 - TRANSMISSION RANGE SENSOR CONNECTOR
21s - 138 40TE AUTOMATIC TRANSAXLERS
SOLENOID/PRESSURE SWITCH ASSY (Continued)
TORQUE CONVERTER
DESCRIPTION
The torque converter (Fig. 293) is a hydraulic
device that couples the engine crankshaft to the
transmission. The torque converter consists of an
outer shell with an internal turbine, a stator, an
overrunning clutch, an impeller and an electronically
applied converter clutch. The converter clutch pro-
vides reduced engine speed and greater fuel economy
when engaged. Clutch engagement also provides
reduced transmission fluid temperatures. The con-
verter clutch engages in third gear. The torque con-
verter 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.
Fig. 293 Torque Converter Assembly
1 - TURBINE
2 - IMPELLER
3 - HUB
4-STATOR
5 - CONVERTER CLUTCH DISC
6 - DRIVE PLATE
21s - 144 40TE AUTOMATIC TRANSAXLERS
OPERATION
The converter impeller (Fig. 299) (driving member),
which is integral to the converter housing and bolted
to the engine drive plate, rotates at engine speed.
The converter turbine (driven member), which reacts
from fluid pressure generated by the impeller, rotates
and turns the transmission input shaft.
TURBINE
As the fluid that was put into motion by the impel-
ler blades strikes the blades of the turbine, some of
the energy and rotational force is transferred into the
turbine and the input shaft. This causes both of them
(turbine and input shaft) to rotate in a clockwise
direction following the impeller. As the fluid is leav-
ing the trailing edges of the turbine's blades it con-
tinues in a ªhinderingº direction back toward the
impeller. If the fluid is not redirected before it strikes
the impeller, it will strike the impeller in such a
direction that it would tend to slow it down.
Fig. 299 Torque Converter Fluid Operation
1 - APPLY PRESSURE 3 - RELEASE PRESSURE
2 - THE PISTON MOVES SLIGHTLY FORWARD 4 - THE PISTON MOVES SLIGHTLY REARWARD
21s - 148 40TE AUTOMATIC TRANSAXLERS
TORQUE CONVERTER (Continued)
STATOR
Torque multiplication is achieved by locking the
stator's over-running clutch to its shaft (Fig. 300).
Under stall conditions (the turbine is stationary), the
oil leaving the turbine blades strikes the face of the
stator blades and tries to rotate them in a counter-
clockwise direction. When this happens the over±run-
ning clutch of the stator locks and holds the stator
from rotating. With the stator locked, the oil strikes
the stator blades and is redirected into a ªhelpingº
direction before it enters the impeller. This circula-
tion of oil from impeller to turbine, turbine to stator,
and stator to impeller, can produce a maximum
torque multiplication of about 2.4:1. 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
turbine are rotating at about the same speed and the
stator is freewheeling, providing no torque multipli-
cation. By applying the turbine's piston to the front
cover's friction material, a total converter engage-
ment can be obtained. The result of this engagement
is a direct 1:1 mechanical link between the engine
and the transmission. The engagement and disengagement of the TCC
are automatic and controlled by the Powertrain Con-
trol Module (PCM). The engagement cannot be acti-
vated in the lower gears because it eliminates the
torque multiplication effect of the torque converter
necessary for acceleration. Inputs that determine clutch engagement are: coolant temperature, vehicle
speed and throttle position. The torque converter
clutch is engaged by the clutch solenoid on the valve
body. The clutch will engage at approximately 56
km/h (35 mph) with light throttle, after the shift to
third gear.
REMOVAL
(1) Remove transmission and torque converter
from vehicle. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 41TE - 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 con-
verter is removed creating an 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 cen-
ter hub clears the oil pump seal. (4) Separate the torque converter from the trans-
mission.
INSTALLATION
Check converter hub and drive notches for sharp
edges, burrs, scratches, or nicks. Polish the hub and
notches with 320/400 grit paper or crocus cloth if nec-
essary. The hub must be smooth to avoid damaging
the pump seal at installation. (1) Lubricate converter hub and oil pump seal lip
with transmission fluid. (2) Place torque converter in position on transmis-
sion.
CAUTION: Do not damage oil pump seal or bushing
while inserting torque converter into the front of the
transmission.
(3) Align torque converter to oil pump seal open-
ing. (4) Insert torque converter hub into oil pump.
(5) While pushing torque converter inward, rotate
converter until converter is fully seated in the oil
pump gears. (6) Check converter seating with a scale and
straightedge (Fig. 301). Surface of converter lugs
should be 1/2 in. to rear of straightedge when con-
verter is fully seated. (7) If necessary, temporarily secure converter with
C-clamp attached to the converter housing. (8) Install the transmission in the vehicle. (Refer
to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC
- 41TE - INSTALLATION)
Fig. 300 Stator Operation
1 - DIRECTION STATOR WILL FREE WHEEL DUE TO OIL
PUSHING ON BACKSIDE OF VANES
2 - FRONT OF ENGINE
3 - INCREASED ANGLE AS OIL STRIKES VANES
4 - DIRECTION STATOR IS LOCKED UP DUE TO OIL PUSHING
AGAINST STATOR VANES
RS 40TE AUTOMATIC TRANSAXLE21s - 149
TORQUE CONVERTER (Continued)
(9)Fill the transmission with the recommended fluid.
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 41TE/FLUID - STANDARD PROCEDURE)
TRANSMISSION CONTROL RELAY
DESCRIPTION
The transmission control relay (Fig. 302) is located
in the Intelligent Power Module (IPM), which is
located on the left side of the engine compartment
between the battery and left fender.
OPERATION
The Transmission Control Relay is supplied fused
B+ voltage, energized by the PCM, and is used to
supply power to the solenoid pack when the trans-
mission is in normal operating mode. When the relay
is ªoffº, no power is supplied to the solenoid pack and
the transmission is in ªlimp-inº mode. After a control-
ler reset (ignition key turned to the ªrunº position or
after cranking engine), the PCM energizes the relay.
Prior to this, the PCM verifies that the contacts are
open by checking for no voltage at the switched bat-
tery terminals. After this is verified, the voltage at
the solenoid pack pressure switches is checked. After
the relay is energized, the PCM monitors the termi-
nals to verify that the voltage is greater than 3 volts.
TRANSMISSION RANGE SENSOR
DESCRIPTION
The Transmission Range Sensor (TRS) is mounted
to the top of the valve body inside the transaxle and can only be serviced by removing the valve body. The
electrical connector extends through the transaxle
case (Fig. 303).
The Transmission Range Sensor (TRS) has four
switch contacts that monitor shift lever position and
send the information to the PCM/TCM.
Fig. 301 Checking Torque Converter Seating
1 - SCALE
2 - STRAIGHTEDGE
Fig. 302 Transmission Control Relay Location
1 - TRANSMISSION CONTROL RELAY
2 - LEFT FENDER
3 - INTELLIGENT POWER MODULE (IPM)
4 - BATTERY
Fig. 303 Transmission Range Sensor (TRS) Location
1 - TRANSMISSION RANGE SENSOR
21s - 150 40TE AUTOMATIC TRANSAXLERS
TORQUE CONVERTER (Continued)
The TRS also has an integrated temperature sen-
sor (thermistor) that communicates transaxle tem-
perature to the TCM and PCM (Fig. 304).
OPERATION
The Transmission Range Sensor (TRS) (Fig. 303) com-
municates shift lever position (SLP) to the PCM/TCM as
a combination of open and closed switches. Each shift
lever position has an assigned combination of switch
states (open/closed) that the PCM/TCM receives from
four sense circuits. The PCM/TCM interprets this infor-
mation and determines the appropriate transaxle gear
position and shift schedule.
Since there are four switches, there are 16 possible
combinations of open and closed switches (codes).
Seven of these codes are related to gear position and
three are recognized as ªbetween gearº codes. This
results in six codes which should never occur. These
are called ªinvalidº codes. An invalid code will result
in a DTC, and the PCM/TCM will then determine the
shift lever position based on pressure switch data.
This allows reasonably normal transmission opera-
tion with a TRS failure.
TRS SWITCH STATES
SLP T42 T41 T3 T1
P CL CL CL OP
R CL OP OP OP
N CL CL OP CL
OD OP OP OP CL
3 OP OP CL OP
L CL OP CL CL
TRANSMISSION TEMPERATURE SENSOR
The TRS has an integrated thermistor (Fig. 304)
that the PCM/TCM uses to monitor the transmis-
sion's sump temperature. Since fluid temperature
can affect transmission shift quality and convertor
lock up, the PCM/TCM requires this information to
determine which shift schedule to operate in. The
PCM also monitors this temperature data so it can
energize the vehicle cooling fan(s) when a transmis-
sion ªoverheatº condition exists. If the thermistor cir-
cuit fails, the PCM/TCM will revert to calculated oil
temperature usage.
CALCULATED TEMPERATURE
A failure in the temperature sensor or circuit will
result in calculated temperature being substituted for
actual temperature. Calculated temperature is a pre-
dicted fluid temperature which is calculated from a
combination of inputs: ² Battery (ambient) temperature
² Engine coolant temperature
² In-gear run time since start-up
REMOVAL
(1) Remove valve body assembly from transaxle.
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 41TE/VALVE BODY - REMOVAL) (2) Remove transmission range sensor retaining
screw and remove sensor from valve body (Fig. 305).
(3) Remove TRS from manual shaft.
Fig. 304 Transmission Temperature Sensor
1 - TRANSMISSION RANGE SENSOR
2 - TEMPERATURE SENSOR
Fig. 305 Remove Transmission Range Sensor
1 - TRANSMISSION RANGE SENSOR
2 - MANUAL VALVE CONTROL PIN
3 - RETAINING SCREW
RS 40TE AUTOMATIC TRANSAXLE21s - 151
TRANSMISSION RANGE SENSOR (Continued)
INSTALLATION
(1) Install transmission range sensor (TRS) to the
valve body and torque retaining screw (Fig. 305) to 5
N´m (45 in. lbs.). (2) Install valve body to transaxle. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC -
41TE/VALVE BODY - INSTALLATION)
VALVE BODY
DESCRIPTION
The valve body assembly consists of a cast alumi-
num valve body, a separator plate, and transfer
plate. The valve body contains valves and check balls
that control fluid delivery to the torque converter
clutch, solenoid/pressure switch assembly, and fric-
tional clutches. The valve body contains the following
components (Fig. 306): ² Regulator valve
² Solenoid switch valve
² Manual valve
² Converter clutch switch valve
² Converter clutch control valve
² Torque converter regulator valve ²
Low/Reverse switch valve
In addition, the valve body also contains the ther-
mal valve, #2,3&4 check balls, the #5 (overdrive)
check valve and the 2/4 accumulator assembly. (Refer
to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC
- 41TE/VALVE BODY - DISASSEMBLY)
OPERATION
NOTE: Refer to the Hydraulic Schematics for a
visual aid in determining valve location, operation
and design.
REGULATOR VALVE
The regulator valve controls hydraulic pressure in
the transaxle. It receives unregulated pressure from
the pump, which works against spring tension to
maintain oil at specific pressures. A system of sleeves
and ports allows the regulator valve to work at one of
three predetermined pressure levels. Regulated oil
pressure is also referred to as ªline pressure.º
Fig. 306 Valve Body Assembly
1 - VALVE BODY 5 - MANUAL VALVE
2 - T/C REGULATOR VALVE 6 - CONVERTER CLUTCH SWITCH VALVE
3 - L/R SWITCH VALVE 7 - SOLENOID SWITCH VALVE
4 - CONVERTER CLUTCH CONTROL VALVE 8 - REGULATOR VALVE
21s - 152 40TE AUTOMATIC TRANSAXLERS
TRANSMISSION RANGE SENSOR (Continued)