clutch ISUZU TF SERIES 2004 Workshop Manual

CONSTRUCTION AND FUNCTION 7A1-33
LEARNING CONTROL

Oil pressure control timing is optimally corrected at the time of clutch engagement and disengagement
and controlled to bring the speed-change time to the value preset to the TCM and compensate the
changes of the engine performance and changes of the transmission with time.

When the gear is shifted, the clutch pressure 2 is optimally corrected so that the speed-change time is as
near as the target value
1 preset to the TCM and the changes in the engine performance and the
changes of the transmission with time can be compensated based on the past speed-change results.

When the clutch is operated to shift the gear, the time of the clutch oil pressure release timing 4 on the
disengagement side is optimally corrected so that the changes of the engine rpm
3 is optimum.


Note:

When the battery terminal is disconnected, contents of learning are cleared and resultantly the speed
change shock may increase. After the vehicle has traveled, learning is repeated and the shock
decreases gradually.





Figure 53. Learning Control

7A1-34 CONSTRUCTION AND FUNCTION
MAJOR INPUT/OUTPUT COMPONENT AND THEIR FUNCTIONS
Speed sensor Detects output shaft revolution and sends rpm signal to TCM.
Turbine sensor Detects input shaft revolution and sends rpm signal to TCM.
Engine speed sensor Inputs engine revolution from engine control computer.
Brake switch Detects brake pedal operated by the driver and sends signal to
TCM.
Inhibitor switch Detects select lever position and sends signal to TCM.
Mode select switch Detects "Power Drive" or "3rd Start" selected by the driver and
sends signal to TCM.
4L switch (4WD Only) Inputs 4L mode from transfer control computer.
ATF thermo sensor Detects ATF temperature and sends signal to TCM.
High clutch oil pressure switch Detects high clutch supply oil pressure and sends signal to
TCM.
2-4 brake oil pressure switch Detects 2-4 brake supply oil pressure and sends signal to
TCM.
Low & Reverse brake oil pressure switch Detects low & reverse brake supply oil pressure and signal to
TCM.
Throttle position sensor Inputs throttle opening angle from engine control computer.
Input
TCM Judges necessary line pressure, gear shifting point and lock-up
operation based on electrical signals from switches and
sensors and sends appropriate signals to solenoids.
Line pressure solenoid Regulates oil pump delivery pressure to the appropriate line
pressure for current driving condition based on signal from
TCM.
Low clutch solenoid Selects appropriate gear shifting position for current driving
condition and regulates low clutch supply oil pressure based on
signal from TCM.
High clutch solenoid Selects appropriate gear shifting position for current driving
condition and regulates high clutch supply oil pressure based
on signal from TCM.
2-4 brake solenoid Selects appropriate gear shifting position for current driving
condition and regulates 2-4 brake supply oil pressure based on
signal from TCM.
Low & Reverse brake solenoid Selects appropriate gear shifting position for current driving
condition and regulates low & reverse brake supply oil
pressure based on signal from TCM.
Lock-up solenoid Regulates lock-up pressure to appropriate level for current
driving conditions based on signal from TCM.
Mode indicator lamp Indicates POWER DRIVE or 3rd START switch position.
Speed meter signal (2WD Only) Outputs vehicle speed to speed meter.
A/T OIL TEMP indicator lamp Indicates A/T OIL TEMP indicator lamp in case of high
temperature.
Output
CHECK TRANS indicator lamp Indicates CHECK TRANS indicator lamp in case of
malfunction.

CONSTRUCTION AND FUNCTION 7A1-35
CONTROL CIRCUIT BLOCK DIAGRAM



Speed sensor
Turbine sensor
Brake switch
Inhibitor switch
Power drive, 3rd start
switch
ATF oil thermo sensor
High clutch oil pressure
switch
2-4 brake oil pressure
switch
Low & reverse brake oil
pressure switch
Transfer control module
(4WD Only)



Engine Control Module
(ECM)
Line pressure solenoid
Low clutch solenoid
High clutch solenoid
2-4 brake solenoid
Low & reverse brake
solenoid
Lock-up solenoid
ATF temperature
indicator lamp
Speed meter (2WD
Only)
Power, 3rd start indicator
lamp
Check trans indicator
lamp
Data link connector Self-diagnosis
function



Transmission
Control
Module
(TCM)
4L mode
Engine
speed
Throttle
angle
Figure 54. Control Circuit Block Diagram

7A1-36 CONSTRUCTION AND FUNCTION
GEAR TRAIN (TRANSMISSION MECHANISM) OPERATION AND
HYDRAULIC CIRCUIT
CONSTRUCTION AND OPERATION
The JR405E consists of two sets of planetary gears, three multiple plate clutches, two multiple plate brakes
and one one-way clutch.





COMPONENT NAME AND FUNCTION
Component Name Symbol Function
Low Clutch L/C Connects the front planetary carrier to the rear
internal gear.
Engaged at 1st, 2nd and 3rd gear.
High Clutch H/C Connects the input shaft to the front planetary
carrier.
Engaged at 3rd and 4th (O/D) gear.
Reverse Clutch R/C Connects the input shaft to the front sun gear.
Engaged at Reverse gear.
Low & Reverse Brake L&R/B Locks the front planetary carrier.
Engaged at L range and Reverse gear.
2-4 Brake 2-4/B Locks the front sun gear.
Engaged at 2nd and 4th (O/D) gear.
Low One-way Clutch L/O.C Allows the front planetary carrier to turn forward
(clockwise) but locks to opposite direction
(counterclockwise).
Operative when accelerating.
Low Clutch Solenoid L/C.S Regulates low clutch pressure.
High Clutch Solenoid H/C.S Regulates high clutch pressure.
Low & Reverse Brake Solenoid L&R/B.S Regulates low & reverse brake pressure.
2-4 Brake Solenoid 2-4/B.S Regulates 2-4 brake pressure.
Lock-up Solenoid L/U.S Regulates lock-up clutch pressure.
High Clutch Oil Pressure SW H/C.P/SW Detects high clutch supply oil pressure.
Low & Reverse Brake Oil Pressure SW L&R/B.P/SWDetects low & reverse brake supply oil pressure.
2-4 Brake Oil Pressure SW 2-4/B.P/SWDetects 2-4 brake supply oil pressure.

CONSTRUCTION AND FUNCTION 7A1-37
COMPONENT AND THEIR OPERATING CONDITION

Clutch Brake Solenoid Pressure Switch
Select
lever
position
Gear
position
Gear
Shift
Lock-
up
L/C
H/C
R/C
L/O.C
L&R/B
2-4/B
L/C.S
H/C.S
L&R/
B.S
2-4/
B.S
L/U.S H/
C.P/
SWL&R/
B.P/
SW2-4
B.P/
SW
P - -

R Reverse -

N - -

1st

2nd
3rd


D
4th

1st

2nd
3rd


3
4th(*1)


1st

2nd

3rd(*1)



2
4th(*1)


1st
2nd(*1)

3rd(*1)



L
4th(*1)



*1:Transmission is shifted at high speed to prevent engine over-run.
- Engaged or operated
- Operative when accelerating

7A1-38 CONSTRUCTION AND FUNCTION
P Range
Though the driving force of the input shaft is transmitted to the rear sun gear and reverse & high clutch drum,
the driving force is not transmitted to the output shaft since all of the clutches and brakes are not engaged.
Therefore, the vehicle can move at this condition. However, since the output shaft is mechanically locked
with the parking pawl, the rear planetary carrier and front internal gear are locked. For this reason, the
vehicle does not move.

CONSTRUCTION AND FUNCTION 7A1-39
N Range
Though the driving force of the input shaft is transmitted to the rear sun gear and reverse & high clutch drum,
the driving force is not transmitted to the output shaft, since all of the clutches and brakes are not engaged.
Therefore, the vehicle can move at this condition.

7A1-40 CONSTRUCTION AND FUNCTION
Reverse Gear in Range
The driving force from the input shaft is transmitted to the rear sun gear and reverse & high clutch drum. In the R
range, the reverse clutch is engaged and the driving force is transmitted to the front sun gear and rotates it
clockwise. The low & reverse brake is also engaged and the front planetary carrier is fixed so that the front pinion
gear does not rotate clockwise but can rotate counterclockwise. As a result, the output shaft rotates
counterclockwise and the vehicle goes back.

CONSTRUCTION AND FUNCTION 7A1-41
1st Gear in D, 3, 2 Range
The driving force from the input shaft is transmitted to the rear sun gear and reverse & high clutch drum.
Since the low clutch is engaged, the movement of the rear internal gear is restricted and, since the low one-
way clutch acts at the same time, counterclockwise rotations of the rear internal gear are locked. As a result,
the driving force transmitted to the rear sun gear rotates the rear planetary carrier clockwise, is decreased in
speed and transmitted to the output shaft.
When decelerating, since the rotating speed of the rear planetary carrier (rear pinion gear) is higher than that
of the rear sun gear and therefore, the rear internal gear attempts to rotate clockwise. At this time, the low
one-way clutch does not act but races and therefore the rear internal gear rotates clockwise. That is, the
reverse torque from the driving shaft is not transmitted to the engine side and therefore, the engine brake
does not act.

7A1-42 CONSTRUCTION AND FUNCTION
1st Gear in L Range
The basic mechanism is the same as in the D, 3, and 2 Range. To apply the engine brake, the low & reverse
brake is engaged to restrict the movement of the low one-way clutch.
When decelerating, since the rear internal gear is fixed, reverse torque from the drive shaft is transmitted to
the engine side so that the engine brake is applied.