Isuzu KB P190. Manual — part 1068

CONSTRUCTION AND FUNCTION 7A1-33

LEARNING FUNCTION

•

Oil pressure control timing is optimally corrected at the time of clutch engagement and disengagement. It

is controlled to bring the shift time to the value preset to the TCM, and compensate for the changes in
engine performance and transmission characteristics.

•

When the gear is shifted, the clutch pressure

2

is optimally corrected so that the shift time

1

is as close

to the target value preset to the TCM. The variation in the engine performance and changes to
transmission characteristics which occur with time, can be compensated for based on the past shift
results.

•

When the clutch is operated to shift the gear, the time of the clutch oil pressure release

4

on the

disengagement side is optimally corrected so that the change of the engine rpm

3

is optimum.

Note:

•

When the battery terminal is disconnected, the contents of learning are cleared and as a result the shift

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 operation 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 sends
signal to TCM.

Accelerator Pedal 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 conditions based on a signal from
TCM.

Low clutch solenoid

Selects appropriate gear shifting position for current driving
conditions and regulates low clutch supply oil pressure based
on a signal from TCM.

High clutch solenoid

Selects appropriate gear shifting position for current driving
conditions and regulates high clutch supply oil pressure based
on a signal from TCM.

2-4 brake solenoid

Selects appropriate gear shifting position for current driving
conditions and regulates 2-4 brake supply oil pressure based
on a signal from TCM.

Low & Reverse brake solenoid

Selects appropriate gear shifting position for current driving
conditions and regulates low & reverse brake supply oil
pressure based on a signal from TCM.

Lock-up solenoid

Regulates lock-up pressure to appropriate level for current
driving conditions based on a signal from TCM.

Mode indicator lamp

Indicates POWER DRIVE or 3rd START switch position.

Speed meter signal (2WD Only)

Outputs vehicle speed to the speed meter.

A/T OIL TEMP indicator lamp

Indicates A/T OIL TEMP indicator lamp in case of high
temperature.

O

utput

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

Tachometer
signal output

APP PWM
position signal
output

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 position 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/SW

Detects low & reverse brake supply oil pressure.

2-4 Brake Oil Pressure SW

2-4/B.P/SW

Detects 2-4 brake supply oil pressure.