2004 ISUZU TF SERIES Tcm

7A3-6 ON-VEHICLE SERVICE (AW30 –40LE)

Diagnosis
Basic Troubleshooting
AW30
–40LE transmission, with Transmission Control
Module (TCM), differs from the Mechanical – Hydraulic
control type transmissions. Accordingly, its
troubleshooting procedure differs also.
Before troubleshooting an TCM, first determine whethe
r
the problem is electrical or mechanical. To do this, just
refer to the basic troubleshooting flowchart provided
below.

If the cause is already known, using the basic
troubleshooting chart below along with the
troubleshooting chart should speed the procedure.




F07R200005-X

7A3-12 ON-VEHICLE SERVICE (AW30 –40LE)

Manual Shifting Test
NOTE: With this test, it can be determined whether the
trouble lies within the electrical circuit or is a mechanical
problem in the transmission.
1. Disconnect TCM connector
Inspect manual driving operation
2. Inspect manual driving operation
Check that the shift and gear positions correspond
with the table.
If the “L", “2", “3" and “D" range gear positions are
difficult to distinguish, do perform the following road
test.
While driving, shift through the “L", “2", “3" and “D"
ranges. Check that the gear change corresponds to
the gear position.
If any abnormality is found in the above test, do
perform the stall, time lag or gear change tests.



RUW37ASH004101
3. Connect TCM connector
With the engine off, connect the TCM connector.


Stall Test



RUW37ALH000101
The object of this test is to check the overall
performance of the transmission and engine b
y
measuring the maximum engine speeds at the “D" and
“ R" ranges.
NOTE:
1. Perform the test at normal operation fluid
temperature (50 – 80 
C or 122 – 176 
F).
2. Do not continuously run this test longer than 5 seconds.

7A3-34 ON-VEHICLE SERVICE (AW30 –40LE)

Transmission Control Module (TCM)


RTW37ALF001801
Removal
Preparation:
Disconnect negative ( –) battery cable.
1. Disconnect the TCM harness connectors.
2. Remove fixing nuts (2 pieces) and TCM with bracket from the car.
NOTE: The TCM is fitted under instrument panel of the
driver's compartment by means of two stud bolts.
3. Remove fixing nuts (2 pieces) and remove TCM
from bracket.


Installation
To install, follow the removal steps in reverse order.

CONSTRUCTION AND FUNCTION 7A1-1

SECTION 7A1
CONSTRUCTION AND FUNCTION
TABLE OF CONTENTS
PAGE
DESCRIPTION ..............................................................................................................................7A1- 3
CONSTRUCTION ....................................................................................................................7A1- 3
MAIN DATA AND SPECIFICATION .....................................................................................7A1- 4
NUMBER PLATE LOCATION ...............................................................................................7A1- 5
ELECTRONIC CONTROL COMPONENTS LOCATION ..................................................7A1- 6
TRANSMISSION CONTROL UNIT (TCM) PERIPHERAL CIRCUIT ..............................7A1- 7
STRUCTURE AND FUNCTION OF COMPONENT ...........................................................7A1- 8
TORQUE CONVERTER (WITH LOCK-UP FUNCTION) ..................................................7A1- 8
OIL PUMP .................................................................................................................................7A1- 9
INPUT SHAFT ..........................................................................................................................7A1- 10
OUTPUT SHAFT ......................................................................................................................7A1- 10
GEAR SHIFTING MECHANISM ............................................................................................7A1- 10
CONTROL VALVE ...................................................................................................................7A1- 14
OIL PASSAGE .........................................................................................................................7A1- 19
PARKING FUNCTION .............................................................................................................7A1- 20
INHIBITOR SWITCH ...............................................................................................................7A1- 21
TURBINE SENSOR .................................................................................................................7A1- 22
SPEED SENSOR .....................................................................................................................7A1- 22
THROTTLE POSITION SENSOR (TPS) .............................................................................7A1- 23
ENGINE SPEED SENSOR (=TDC SENSOR) ....................................................................7A1- 23
BRAKE SWITCH ......................................................................................................................7A1- 24
MODE SELECT SWITCH .......................................................................................................7A1- 24
TRANSMISSION CONTROL MODULE (TCM) ..................................................................7A1- 25
CONTROL MECHANISM ............................................................................................................7A1- 26
CONTENT OF FUNCTION AND CONTROL ......................................................................7A1- 26
CONTROL ITEM, INPUT AND OUTPUT .................................................................... 7A1- 29
LINE PRESSURE CONTROL ..................................................................................... 7A1- 30

CONSTRUCTION AND FUNCTION 7A1-3

DESCRIPTION
CONSTRUCTION



































1 Converter Housing 6 Low Clutch 11 Oil Pump
2 Torque Converter 7 Low & Reverse Brake 12 Control Valve
3 High Clutch 8 Output Shaft 13 Low One-way Clutch
4 Reverse Clutch 9 Extension Housing 14 Parking Gear
5 2-4 Brake 10 Input Shaft

Figure 1. Construction of Automatic Transmission

The JR405E automatic transmission is electrically controlled by a microcomputer transmission control module
(TCM). There are four forward speeds and one reverse speed.
This JR405E automatic transmission employs a clutch pressure direct control system (Direct Electronic Shift
Control: DESC) using a duty cycle type solenoid, which ensures high shift quality.
This transmission also controls learning and constantly checks the time of each clutch and brake required for
the speed change to match this time with the target value for the optimum speed change.

The TCM will automatically select the most appropriate shift points and lock-up points depending on the
throttle opening angle, the vehicle speed and the vehicle load.
If any trouble arises in the vehicle sensor, throttle sensor, solenoid, etc., the fail-safe control function is
activated to keep the running performance.
Problems with the sensors, the solenoids can be quickly detected with the self diagnosis procedure described
in this manual.

The JR405E automatic transmission consists of the torque converter, the oil pump, the input shaft, the out put
shaft, the planetary gears and the control valve.
The gear train consists of two planetary gear sets and three multiple plate clutches in combination with two
multiple plate brakes and a one-way clutch.
2WD
4WD

7A1-6 CONSTRUCTION AND FUNCTION
ELECTRONIC CONTROL COMPONENTS LOCATION

4WD Only 4WD Only
Instrument panel (Meter)







Speed meter (2WD Only)
Shift position indicator lamp
POWER DRIVE, 3rd START
indicator lamp
A/T OIL TEMP indicator lamp
CHECK TRANS indicator lam
p

Brake pedal





Brake Switch
Select lever








Power Drive
, 3rd Start select switch
Transmission Control Module (TCM)
Electrical source






Ignition
Battery voltage
Speed sensor
Turbine sensor
Inhibitor switch
ATF thermo sensor
High clutch oil pressure switch
2-4 brake oil pressure switch
Low & Reverse brake oil pressure
switch
Line pressure solenoid
Low clutch solenoid
High clutch solenoid
2-4 brake solenoid
Low & Reverse brake solenoid
Lock-up solenoid
Transmission
Transfer Control Module
Transfer




4L mode switch
Engine




Engine speed sensor
Throttle Position Sensor


Engine Control Module (ECM)
Data link connector

CONSTRUCTION AND FUNCTION 7A1-7

TRANSMISSION CONTROL UNIT (TCM) PERIPHERAL CIRCUIT



































































Figure 4. TCM Peripheral Circuit

CONSTRUCTION AND FUNCTION 7A1-11


The JR405E consists of two sets of planetary gears, which are called front planetary gear and rear
planetary gear.

The sun gear of front planetary gear is fixed to the drive plates of 2-4 brake and reverse clutch.

The planetary carrier of front planetary gear is fixed to the drum of low clutch, the drive plates of low &
reverse brake and the hub of high clutch.

The internal gear of front planetary gear and the planetary carrier of rear planetary gear are connected as
one, and they are fixed to output shaft.

The sun gear of rear planetary gear is fixed to input shaft.

The internal gear of rear planetary gear is fixed to the hub of low clutch.

Clutch and Brake

Basic structure of the clutch and brake is shown in the figures below.

In the figure A, the clutch plates (drive plate and driven plate) are in the fluid so that they slip against each
other transmitting no power.

Figure B shows the condition where the oil pressure is acting on the piston. The clutch plates are fitted
to each other under pressure transmitting the rotations of the clutch drum to the clutch hub.

When the oil pressure is removed from the piston, the clutch returns to the condition in the figure A by the
return spring.


Figure 13. Basic Construction of Clutch and Brake

Low Clutch, High Clutch and Reverse Clutch (Multi-Plate Clutch)

The multi-plate clutch is composed of drive plates and driven plates. By applying the oil pressure onto
the end surface of the plates, the clutch is engaged or disengaged. The oil pressure is adjusted with the
control valve according to the signal from the TCM.

All clutches use dish plates to prevent uncontrolled operation of the clutches when engaged, causing a
shock.

For the reverse clutch, a piston check ball is used to release the oil pressure for the purpose of preventing
the clutch drag due to oil pressure generated by residual ATF because of the centrifugal force while the
clutch is racing (under no oil pressure).

For the low clutch and high clutch, a centrifugal balance chamber always full of ATF is provided to offset
the excessive oil pressure, for the purpose of preventing the clutch drag due to oil pressure generated by
residual ATF because of the centrifugal force while the clutch is racing (under no oil pressure).

The solenoid in the control valve is driven based on the speed change signal from TCM and moves the
shift valve, thereby engaging the drive plate and driven plate through the piston of each clutch.

Resultantly, elements of the planetary gear unit are combined.

When the oil pressure is removed, the piston returns to the original position by the force of the return
spring.