OPERATION
The Brake/Transmission Shift Interlock (BTSI)
Solenoid prevents the transmission shift lever from
being moved out of PARK (P) unless the brake pedal
is applied. The BTSI solenoid is hardwired to and
controlled by the Intelligent Power Module (IPM).
Battery voltage is applied to one side of the solenoid
with the ignition key is in either the OFF, ON/RUN,
or START positions (Fig. 293). The ground side of the
solenoid is controlled by a driver within the IPM. It
relies on voltage supplied from the stop lamp switch
to the stop lamp sense circuit within the IPM to tell
when the brake pedal is depressed. When the brake
pedal is depressed, the ground circuit opens, de-ener-
gizing the solenoid. When the brake pedal is
released, the ground circuit is closed, energizing the
solenoid.
When the ignition key is in either the OFF,
ON/RUN, or START positions, the BTSI solenoid is
energized, and the solenoid plunger hook pulls the
shift lever pawl into position, prohibiting the shift
lever from moving out of PARK (P) (Fig. 294). When
the brake pedal is depressed, the ground circuit
opens, de-energizing the solenoid. This moves the
gearshift lever pawl out of the way (Fig. 295), allow-
ing the shift lever to be moved into any gear position.
Fig. 293 Ignition Key/Switch Positions
1 - ACC
2 - LOCK
3 - OFF
4 - ON/RUN
5-START
Fig. 294 Pawl Engaged to Shift Lever
1 - GEAR SHIFT LEVER
2 - GEAR SHIFT LEVER PAWL
Fig. 295 Pawl Disengaged From Shift Lever
1 - GEAR SHIFT LEVER
2 - GEAR SHIFT LEVER PAWL
RS41TE AUTOMATIC TRANSAXLE21 - 265
SHIFT INTERLOCK SOLENOID (Continued)
A conventional mechanical interlock system is also
used. This system manually prohibits shifter move-
ment when the ignition switch is in the LOCK or
ACC positions. Solenoid operation is not required in
these key positions.
For intended BTSI system operation, refer to the
following chart:
ACTION EXPECTED RESPONSE
1. Turn key to the9OFF9
position.1. Shifter CAN be shifted
out of park with brake
pedal applied.
2. Turn key to the
9ON/RUN9position.2. Shifter CANNOT be
shifted out of park.
3. Turn key to the
9ON/RUN9position and
depress the brake pedal.3. Shifter CAN be shifted
out of park.
4. Leave shifter in any
gear and try to return key
to the9LOCK9or9ACC9
position.4. Key cannot be
returned to the9LOCK9or
9ACC9position.
5. Return shifter to
9PARK9and try to remove
the key.5. Key can be removed
(after returning to9LOCK9
position).
6. With the key removed,
try to shift out of9PARK9.6. Shifter cannot be
shifted out of9PARK9.
NOTE: Any failure to meet these expected
responses requires system adjustment or repair.
DIAGNOSIS AND TESTING - BRAKE/
TRANSMISSION SHIFT INTERLOCK SOLENOID
For intended BTSI system operation, refer to the
following chart:
ACTION EXPECTED RESPONSE
1. Turn key to the9OFF9
position.1. Shifter CAN be shifted
out of park with brake
pedal applied.
2. Turn key to the
9ON/RUN9position.2. Shifter CANNOT be
shifted out of park.
3. Turn key to the
9ON/RUN9position and
depress the brake pedal.3. Shifter CAN be shifted
out of park.
4. Leave shifter in any
gear and try to return key
to the9LOCK9or9ACC9
position.4. Key cannot be
returned to the9LOCK9or
9ACC9position.
5. Return shifter to
9PARK9and try to remove
the key.5. Key can be removed
(after returning to9LOCK9
position).
ACTION EXPECTED RESPONSE
6. With the key removed,
try to shift out of9PARK9.6. Shifter cannot be
shifted out of9PARK9.
NOTE: Any failure to meet these expected
responses requires system repair. Refer to the
appropriate Diagnostic Information.
REMOVAL
(1) Disconnect battery negative cable.
(2) Remove instrument panel lower shroud (Fig.
296).
(3) Remove knee bolster (Fig. 297).
Fig. 296 Instrument Panel Lower Silencer
1 - INSTRUMENT PANEL LOWER SILENCER
Fig. 297 Knee Bolster
1 - KNEE BOLSTER
21 - 266 41TE AUTOMATIC TRANSAXLERS
SHIFT INTERLOCK SOLENOID (Continued)
(3) Install steering column lower shroud.
(4) Install knee bolster (Fig. 302).
(5) Install instrument panel lower silencer (Fig.
303).
(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. 304)
is external to the transaxle and mounted to thetransaxle 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. 302 Knee Bolster
1 - KNEE BOLSTER
Fig. 303 Instrument Panel Lower Silencer
1 - INSTRUMENT PANEL LOWER SILENCER
Fig. 304 Solenoid/Pressure Switch Assembly
1 - SOLENOID AND PRESSURE SWITCH ASSEMBLY
21 - 268 41TE AUTOMATIC TRANSAXLERS
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, the ªQuick-Learnº procedure must
be performed. (Refer to 8 - ELECTRICAL/ELEC-
TRONIC 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. 305).
(4) Disconnect input speed sensor connector (Fig.
305).
Fig. 305 Transmission Connectors
1 - SOLENOID PACK CONNECTOR
2 - INPUT SPEED SENSOR CONNECTOR
3 - OUTPUT SPEED SENSOR CONNECTOR
4 - TRANSMISSION RANGE SENSOR CONNECTOR
RS41TE AUTOMATIC TRANSAXLE21 - 269
SOLENOID/PRESSURE SWITCH ASSY (Continued)
(5) Remove input speed sensor (Fig. 306).
(6) Remove three (3) solenoid/pressure switch
assembly-to-transaxle case bolts (Fig. 307).
(7) Remove solenoid/pressure switch assembly and
gasket (Fig. 308). Use care to prevent gasket mate-
rial and foreign objects from become lodged in the
transaxle case ports.
INSTALLATION
NOTE: If solenoid/pressure switch assembly is
being replaced, it is necessary to perform the
ªQuick-Learnº procedure. (Refer to 8 - ELECTRI-
CAL/ELECTRONIC CONTROL MODULES/TRANS-
MISSION CONTROL MODULE - STANDARD
PROCEDURE)
(1) Install solenoid/pressure switch assembly and
new gasket to transaxle (Fig. 308).
(2) Install and torque three (3) bolts (Fig. 307) to
13 N´m (110 in. lbs.).
(3) Install input speed sensor (Fig. 306) and torque
to 27 N´m (20 ft. lbs.).
(4) Connect input speed sensor connector (Fig.
305).
(5) Install solenoid/pressure switch 8-way connec-
tor and torque to 4 N´m (35 in. lbs.) (Fig. 305).
(6) Install air cleaner assembly.
(7) Connect battery negative cable.
(8) If solenoid/pressure switch assembly was
replaced, perform the ªQuick-Learnº procedure.
(Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/TRANSMISSION CONTROL
MODULE - STANDARD PROCEDURE)
Fig. 306 Input Speed Sensor
1 - INPUT SPEED SENSOR
Fig. 307 Solenoid/Pressure Switch Assembly-to-
Case Bolts
1 - BOLTS
2 - SOLENOID AND PRESSURE SWITCH ASSEMBLY
Fig. 308 Solenoid/Pressure Switch Assembly and
Gasket
1 - SOLENOID/PRESSURE SWITCH ASSEMBLY
2 - GASKET
21 - 270 41TE AUTOMATIC TRANSAXLERS
SOLENOID/PRESSURE SWITCH ASSY (Continued)
REMOVAL
(1) Disconnect battery negative cable.
(2) Disconnect input speed sensor connector (Fig.
312).
(3) Unscrew and remove input speed sensor (Fig.
313).
(4) Inspect speed sensor o-ring (Fig. 314) and
replace if necessary.
INSTALLATION
(1) Verify o-ring is installed into position (Fig.
314).
(2) Install and tighten input speed sensor to 27
N´m (20 ft. lbs.) (Fig. 313).
(3) Connect speed sensor connector (Fig. 312).
(4) Connect battery negative cable.
Fig. 312 Transmission Connectors
1 - SOLENOID PACK CONNECTOR
2 - INPUT SPEED SENSOR CONNECTOR
3 - OUTPUT SPEED SENSOR CONNECTOR
4 - TRANSMISSION RANGE SENSOR CONNECTOR
Fig. 313 Input (Turbine) Speed Sensor
1 - INPUT SPEED SENSOR
Fig. 314 O-ring Location
1 - INPUT SPEED SENSOR
2 - O-RING
21 - 272 41TE AUTOMATIC TRANSAXLERS
SPEED SENSOR - INPUT (Continued)
REMOVAL
(1) Disconnect battery negative cable.
(2) Raise vehicle on hoist.
(3) Disconnect output speed sensor connector (Fig.
318).
(4) Unscrew and remove output speed sensor (Fig.
319).
(5) Inspect speed sensor o-ring (Fig. 320) and
replace if necessary.
INSTALLATION
(1) Verify o-ring is installed into position (Fig.
320).
(2) Install and tighten input speed sensor to 27
N´m (20 ft. lbs.).
(3) Connect speed sensor connector (Fig. 318).
(4) Connect battery negative cable.
Fig. 318 Transmission Connectors
1 - SOLENOID PACK CONNECTOR
2 - INPUT SPEED SENSOR CONNECTOR
3 - OUTPUT SPEED SENSOR CONNECTOR
4 - TRANSMISSION RANGE SENSOR CONNECTOR
Fig. 319 Output Speed Sensor
1 - OUTPUT SPEED SENSOR
Fig. 320 O-ring Location
1 - OUTPUT SPEED SENSOR
2 - O-RING
21 - 274 41TE AUTOMATIC TRANSAXLERS
SPEED SENSOR - OUTPUT (Continued)
TRANSMISSION CONTROL
RELAY
DESCRIPTION
The transmission control relay (Fig. 330) 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 relay is supplied fused B+ voltage, energized by
the PCM/TCM, and is used to supply power to the sole-
noid pack when the transmission 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 controller reset (ignition key turned to the
ªrunº position or after cranking engine), the PCM/TCM
energizes the relay. Prior to this, the PCM/TCM verifies
that the contacts are open by checking for no voltage at
the switched battery terminals. After this is verified,
the voltage at the solenoid pack pressure switches is
checked. After the relay is energized, the PCM/TCM
monitors the terminals 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 andcan only be serviced by removing the valve body. The
electrical connector extends through the transaxle
case (Fig. 331).
The Transmission Range Sensor (TRS) has four
switch contacts that monitor shift lever position and
send the information to the PCM/TCM.
The TRS also has an integrated temperature sen-
sor (thermistor) that communicates transaxle tem-
perature to the TCM and PCM (Fig. 332).
Fig. 330 Transmission Control Relay Location
1 - TRANSMISSION CONTROL RELAY
2 - LEFT FENDER
3 - INTELLIGENT POWER MODULE (IPM)
4 - BATTERY
Fig. 331 Transmission Range Sensor (TRS)
Location
1 - TRANSMISSION RANGE SENSOR
Fig. 332 Transmission Temperature Sensor
1 - TRANSMISSION RANGE SENSOR
2 - TEMPERATURE SENSOR
RS41TE AUTOMATIC TRANSAXLE21 - 281