
SPEED SENSOR - INPUT
DESCRIPTION
The Input Speed Sensor is a two-wire magnetic
pickup device that generates AC signals as rotation
occurs. It is threaded into the transaxle case (Fig.
281), sealed with an o-ring (Fig. 282), and is consid-
ered a primary input to the Powertrain/Transmission
Control Module.
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 (Fig.
283), an AC voltage is generated and sent to the
PCM/TCM. The PCM/TCM interprets this informa-
tion as input shaft rpm.
The PCM/TCM compares the input speed signal
with output speed signal to determine the following: ² Transmission gear ratio
² Speed ratio error detection
² CVI calculation
The PCM/TCM also compares the input speed sig-
nal and the engine speed signal to determine the fol-
lowing: ² Torque converter clutch slippage
² Torque converter element speed ratio
Fig. 281 Input Speed Sensor Location
1 - INPUT SPEED SENSOR
Fig. 282 O-Ring Location
1 - INPUT SPEED SENSOR
2 - O-RING
Fig. 283 Sensor Relation to Input Clutch Hub
1 - INPUT SPEED SENSOR
2 - TRANSAXLE CASE
3 - INPUT CLUTCH HUB
21s - 140 40TE AUTOMATIC TRANSAXLERS

SPEED SENSOR - OUTPUT
DESCRIPTION
The Output Speed Sensor is a two-wire magnetic
pickup device that generates an AC signal as rotation
occurs. It is threaded into the transaxle case (Fig.
287), sealed with an o-ring (Fig. 288), and is consid-
ered a primary input to the Powetrain/Transmission
Control Module.
OPERATION
The Output Speed Sensor provides information on
how fast the output shaft is rotating. As the rear
planetary carrier park pawl lugs pass by the sensor
coil (Fig. 289), an AC voltage is generated and sent to
the PCM/TCM. The PCM/TCM interprets this infor-
mation as output shaft rpm.
The PCM/TCM compares the input and output
speed signals to determine the following: ² Transmission gear ratio
² Speed ratio error detection
² CVI calculation
VEHICLE SPEED SIGNAL
The vehicle speed signal is taken from the Output
Speed Sensor. The PCM converts this signal into a
pulse per mile signal and sends the vehicle speed
message across the communication bus to the BCM.
The BCM sends this signal to the Instrument Cluster
to display vehicle speed to the driver. The vehicle
speed signal pulse is roughly 8000 pulses per mile.
Fig. 287 Output Speed Sensor
1 - OUTPUT SPEED SENSOR
Fig. 288 O-Ring Location
1 - OUTPUT SPEED SENSOR
2 - O-RING
Fig. 289 Sensor Relation to Planet Carrier Park Pawl
1 - OUTPUT SPEED SENSOR
2 - REAR PLANET CARRIER/OUTPUT SHAFT ASSEMBLY
3 - TRANSAXLE CASE
21s - 142 40TE AUTOMATIC TRANSAXLERS

(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)

SOLENOID SWITCH VALVE
The solenoid switch valve controls line pressure
from the LR/CC solenoid. In one position, it allows
the low/reverse clutch to be pressurized. In the other,
it directs line pressure to the converter control and
converter clutch valves.
MANUAL VALVE
The manual valve is operated by the mechanical
shift linkage. Its primary responsibility is to send
line pressure to the appropriate hydraulic circuits
and solenoids. The valve has three operating ranges
or positions.
CONVERTER CLUTCH SWITCH VALVE
The main responsibility of the converter clutch
switch valve is to control hydraulic pressure applied
to the front (off) side of the converter clutch piston.
Line pressure from the regulator valve is fed to the
torque converter regulator valve, where it passes
through the valve, and is slightly regulated. The
pressure is then directed to the converter clutch
switch valve and to the front side of the converter
clutch piston. This pressure pushes the piston back
and disengages the converter clutch.
CONVERTER CLUTCH CONTROL VALVE
The converter clutch control valve controls the
back (on) side of the torque converter clutch. When
the PCM/TCM energizes or modulates the LR/CC
solenoid to apply the converter clutch piston, both
the converter clutch control valve and the converter
control valve move, allowing pressure to be applied to
the back side of the clutch.
T/C REGULATOR VALVE
The torque converter regulator valve slightly regu-
lates the flow of fluid to the torque converter.
LOW/REVERSE SWITCH VALVE
The low/reverse clutch is applied from different
sources, depending on whether low (1st) gear or
reverse is selected. The low/reverse switch valve
alternates positions depending on from which direc-
tion fluid pressure is applied. By design, when the
valve is shifted by fluid pressure from one channel,
the opposing channel is blocked. The switch valve
alienates the possibility of a sticking ball check, thus
providing consistent application of the low/reverse
clutch under all operating conditions.
REMOVAL
NOTE: If valve body is replaced or reconditioned,
the TCM Quick Learn Procedure must be per-
formed. (Refer t o 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/TRANSMISSION CONTROL
MODULE - STANDARD PROCEDURE)
(1) Disconnect battery negative cable.
(2) Disconnect gearshift cable from manual valve
lever. (3) Remove manual valve lever from manual shaft.
(4) Raise vehicle on hoist.
(5) Remove oil pan bolts (Fig. 307).
(6) Remove oil pan (Fig. 308).
Fig. 307 Oil Pan Bolts
1 - OIL PAN BOLTS (USE RTV UNDER BOLT HEADS)
Fig. 308 Oil Pan
1 - OIL PAN
2 - 1/8 INCH BEAD OF RTV SEALANT
3 - OIL FILTER
RS 40TE AUTOMATIC TRANSAXLE21s - 153
VALVE BODY (Continued)

DISASSEMBLY
NOTE: If valve body assembly is being recondi-
tioned, the PCM/TCM Quick Learn Procedure must
be performed. (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/TRANSMISSION
CONTROL MODULE - STANDARD PROCEDURE)
(1) Remove manual shaft seal (Fig. 313).
(2) Remove Transmission Range Sensor retaining
screw (Fig. 314). (3) Remove Manual Shaft/Rooster Comb and
Transmission Range Sensor (Fig. 315).
(4) Remove 2/4 Accumulator Retaining Plate (Fig.
316).
Fig. 313 Manual Shaft Seal
1 - SEAL
2 - MANUAL SHAFT
Fig. 314 Remove Transmission Range Sensor
1 - TRANSMISSION RANGE SENSOR
2 - MANUAL VALVE CONTROL PIN
3 - RETAINING SCREW
Fig. 315 Manual Shaft/Rooster Comb and Transmission Range Sensor
1 - TRANSMISSION RANGE SENSOR
2 - MANUAL SHAFT
3 - ROOSTER COMB
Fig. 316 2/4 Accumulator Retaining Plate
1 - 2±4 ACCUMULATOR RETAINING PLATE
2 - DETENT SPRING
RS 40TE AUTOMATIC TRANSAXLE21s - 155
VALVE BODY (Continued)

(15) Remove remaining retainers as shown in (Fig.
327). (16) Remove valves and springs as shown in (Fig.
328).
NOTE: Refer to Valve Body Cleaning and Inspection
for cleaning procedures.
ASSEMBLY
NOTE: If valve body assembly is reconditioned, the
PCM/TCM Quick Learn Procedure must be per-
formed. (Refer t o 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/TRANSMISSION CONTROL
MODULE - STANDARD PROCEDURE)
(1) Install valves and springs as shown in (Fig.
328).
Fig. 328 Springs and Valves Location
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
Fig. 327 Valve Retainer Location
1 - RETAINER
2 - RETAINER
RS 40TE AUTOMATIC TRANSAXLE21s - 159
VALVE BODY (Continued)

(16) Install manual shaft seal (Fig. 343).
INSTALLATION
NOTE: If valve body assembly is being replaced or
reconditioned, it is necessary to perform the TCM
Quick Learn Procedure. (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/TRANSMISSION
CONTROL MODULE - STANDARD PROCEDURE)
(1) Install valve body assembly to transaxle (Fig.
344). Install and torque valve body-to-transaxle case
bolts (Fig. 345) to 12 N´m (105 in. lbs.). (2) Install transaxle oil filter (Fig. 346). Inspect
the o-ring and replace if necessary.
Fig. 343 Manual Shaft Seal
1 - SEAL
2 - MANUAL SHAFT
Fig. 344 Valve Body Removal/Installation
1 - VALVE BODY
Fig. 345 Valve Body Attaching Bolts
1 - VALVE BODY ATTACHING BOLTS (18)
2 - VALVE BODY
Fig. 346 Filter and O-Ring
1 - OIL FILTER
2 - O-RING
21s - 164 40TE AUTOMATIC TRANSAXLERS
VALVE BODY (Continued)