2004 ISUZU TF SERIES change time

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

7A1-26 CONSTRUCTION AND FUNCTION
CONTROL MECHANISM
CONTENT OF FUNCTION AND CONTROL
Item Description
Line pressure control TCM issues a signal according to the vehicle traveling, engine load and other conditions to
TCM and the ON/OFF type line pressure solenoid is driven to switch the line pressure to
high or low pressure.
The line pressure solenoid is switched to the low pressure side when the solenoid is turned
ON (power supplied) and to the high pressure side when turned OFF (no power supplied).
In the forward travel range (D, 3, 2, L range), the line pressure decreases lower than that in
the P, N, and R range through the oil pressure circuit for the forward travel range.


Gear shift control The TCM issues a shift solenoid drive signal based on the traveling mode switch, inhibitor
switch, vehicle speed, throttle opening and other input signal to control the optimum gear
position automatically.
Speed change features have been set up to the TCM; the normal mode is suited to usual
traveling and the power mode is appropriate when the vehicle is loaded or accelerates the
speed.
In addition, speed change features used only for high oil temperature, hill climbing, and
down have been set up to the TCM, which are automatically switched depending on the
traveling conditions.
When the oil temperature is low (below 10
C), speed change from the third to the fourth
speed is prohibited by the gear shift control.


Shift pattern selection
control
According to a vehicle condition, the TCM selects the following shift pattern.

Selection Priority Shift Pattern 3rd Start Lamp Power Drive Lamp
High High Temperature OFF OFF
3rd Start ON
4L
Power SW Off
OFF
Down Slop Power SW On
Power ON
Up Slope
Low Normal
OFF
OFF

- High temperature mode -
High temperature mode setting condition
ATF temperature: More than 123
C
Above condition is met for more than 10 seconds.
High temperature mode cancel condition
ATF temperature: Less than 116
C
Above condition is met for more than 10 seconds.

- 3rd start mode -
3rd start mode setting condition
3rd start switch: On  Off (Pushed)
Vehicle speed: Less than 11km/h
ATF temperature: Less than 115
C
Throttle position: Less than 8%
Select lever position: D range
Above conditions are met at the same time.
3rd start mode reset condition
3rd start switch: On  Off again(Pushed again)
Vehicle speed: More than 34km/h
Select lever position: Other than D range
At least, one of above conditions is met.

CONSTRUCTION AND FUNCTION 7A1-27
Item Description
- 4L mode -
4L mode setting condition
4L switch: On
Vehicle speed: More than 5km/h
Above conditions are met at the same time.
4L mode reset condition
4L switch: Off
Vehicle speed: Less than 4km/h
Above conditions are met at the same time.

- Down slope mode -
Down slope mode setting condition
Brake switch: On
Engine idle condition: More than 2.5 seconds
Select lever position: D or 3 range
Vehicle speed: More than 55km/h
Vehicle speed change: More than 1km/h
Above conditions are met at the same time.
Down slope mode reset condition
Engine idle condition: Not idle condition
Select lever position: Other than D or 3 range
At least, one of above conditions is met.

- Power Mode -
When power drive switch is On at only D range or 3 range, the shift change is performed by
1 – 4 speed based on shift diagram set as power pattern.

- Up slope mode -
Up-slope reasoning value is calculated from the average throttle angle and the average
acceleration. Otherwise, up-slope reasoning value is calculated from the vehicle speed.
TCM judges as up-slope mode when the former is bigger than latter.


Lock-up control The lock-up solenoid adjusts the pressure based on the signal from the TCM according to
the vehicle speed, throttle opening and other input signals based on the pre-set lock-up
point to control the lock-up.
Smooth lock-up control engages and disengages the clutch smoothly at the time of lock-up.
When the oil temperature is low (below 20
C) or high (above 128
C), lock-up is prohibited
even when the vehicle is at a lock-up speed.
The lock-up is disengaged also when the throttle is closed.
Direct electronic shift
control (DESC)
The duty cycle type solenoid is used for each clutch and brake. The solenoid adjusts the
clutch pressure to be suited to the engine load and vehicle traveling condition based on the
signal from the TCM. The pressure switch provided in the control valve oil passage sends
the oil pressure condition to the TCM to control the disengagement and engagement of the
clutch and brake directly and finely.
Learning control Learning is controlled to correct the oil pressure control timing to engage or disengage the
clutch optimally in order to compensate changes of the engine performance and changes
of the transmission with time. It is controlled to bring the speed-change time closer to the
value pre-set to the TCM.

7A1-30 CONSTRUCTION AND FUNCTION
LINE PRESSURE CONTROL

Either the throttle opening, vehicle speed, turbine rotational speed, ATF temperature or speed-change
range signal appropriate under the situation is issued from the TCM. The ON/OFF type line pressure
solenoid is actuated and switches the line pressure to high or low pressure.

The line pressure generated by the oil pump acts on the point A of the pressure regulator valve. When
the pressure control solenoid is turned ON by the signal from the TCM, the solenoid pressure does not
act. The line pressure is adjusted to match the spring force acting on the right side of the pressure
regulator valve.

When the pressure control solenoid is turned OFF, the solenoid pressure acts so that the line pressure is
adjusted to match the spring force acting on the right side of the pressure regulator valve.

As a result, the line pressure is adjusted to be low when the pressure control solenoid is ON and to be
high when the pressure control solenoid is OFF.

In the D, 3, 2 and L range, the line pressure through the oil pressure circuit acts onto the point B of the
pressure regulator valve and the pressure regulator valve moves so as to increase the pressure to be
drained, so that the line pressure is adjusted to be lower than the P, N, and R range by the difference of
area at the point B.




Figure 50. Line Pressure Control

LOCK-UP CONTROL

The lock-up solenoid adjusts the pressure and controls the lock-up based on the pre-set lock-up point,
according to the vehicle speed, throttle opening, engine rotations, turbine rotations and ATF temperature
input signal, based on the signal from the TCM.

Smooth lock-up control is employed to engage or disengage the clutch smoothly at the time of lock-up.

When the oil temperature is low (below 20C) or high (over 128C), lock-up is disengaged even though
the vehicle is at the lock-up speed.

The lock-up is disengaged also when the throttle is closed.

When the TCM determines the lock-up engagement, the DUTY ratio to supply power to the lock-up
solenoid is gradually increased (5% to 95%) and the oil between the lock-up piston and converter cover is
gradually drained.
As a result, the lock-up piston is fitted slowly under pressure to the converter cover securing smooth lock-
up engagement.

CONSTRUCTION AND FUNCTION 7A1-31


Figure 51. Lock-up Control

DIRECT ELECTRIC SHIFT CONTROL (DESC)
Feature

Based on the each switch signals (low & reverse brake pressure, 2-4 brake pressure & high clutch
pressure) and sensors signals (turbine sensor, speed sensor, engine speed signal & throttle position
signal), duty cycle type solenoid adjusts the clutch pressure to match the engine load and vehicle
traveling condition. By this result, controlling the engagement and disengagement of the clutch and brake
pressure is directly and accurately controlled via TCM, which is not realized in previous accumulator type.
Operation

Instead of the previous system (on/off type of shift solenoid and shift valve), the combination of duty cycle
type solenoid and amplifier (Amp) valve are used to adjust the clutch pressure to match the engine load
and vehicle traveling condition based on the signal from the TCM, and the pressure switch provided in the
oil passage of the control valve transmits the oil pressure condition at that time to TCM, thus controlling
the engagement and disengagement of the clutch and brake directly and finely.

When the gear is shifted from the 2nd to 3rd, 3rd to 4th (O/D), 4th (O/D) to 3rd and 3rd to 2nd, the clutch
pressure on the engagement side and that on the disengagement side are simultaneously controlled.
As a result, engine racing or clutch drag is prevented securing smooth and quick speed change response

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

7A2-2 DIAGNOSIS (JR405E)
PAGE
DTC P0748 (FLASH CODE 35) LINE PRESSURE SOLENOID FAILURE.......................7A2-60
DTC P1860 (FLASH CODE 36) LOCK-UP DUTY SOLENOID FAILURE.........................7A2-62
DTC P1853 (FLASH CODE 26) LOW & REVERSE BRAKE PRESSURE
SWITCH FAILURE......................................................................................................................7A2-64
DTC P1858 (FLASH CODE 27) 2-4 BRAKE PRESSURE SWITCH FAILURE................7A2-68
DTC P1863 (FLASH CODE 28) HIGH CLUTCH PRESSURE SWITCH FAILURE..........7A2-72
DTC P0731 (FLASH CODE 41) 1st GEAR RATIO ERROR................................................7A2-76
DTC P0732 (FLASH CODE 42) 2nd GEAR RATIO ERROR...............................................7A2-76
DTC P0733 (FLASH CODE 43) 3rd GEAR RATIO ERROR................................................7A2-76
DTC P0734 (FLASH CODE 44) 4th GEAR RATIO ERROR................................................7A2-76
DTC P1750 (FLASH CODE 51) LOW & REVERSE BRAKE FAIL-SAFE
VALVE FAILURE........................................................................................................................7A2-78
DTC P1755 (FLASH CODE 52) 2-4 BRAKE FAIL-SAFE VALVE FAILURE....................7A2-80
DTC P0602 Programming Error ................................................................................... 7A2-82
SYMPTOM DIAGNOSIS.............................................................................................................7A2-83
SYMPTOM DIAGNOSIS TABLE...............................................................................................7A2-84
No. A1: VEHICLE DOES NOT RUN IN D, 3, 2, L and RANGE..........................................7A2-93
No. A2: VEHICLE DOES NOT RUN IN R RANGE................................................................7A2-94
No. A3: VEHICLE DOES NOT RUN IN D, 3, 2 and RANGE...............................................7A2-95
No. B1: VEHICLE RUNS IN N RANGE...................................................................................7A2-96
No. B2: POOR ACCELERATION AT STARTING.................................................................7A2-97
No. B3: ENGINE RACE UP DURING STARTING (SLIP)....................................................7A2-100
No. B4: LARGE SHOCK WHEN SHIFT LEVER IS CHANGED TO N TO D
RANGE OR N TO R RANGE....................................................................................................7A2-103
No. B5: ENGINE STALLS WHEN SELECTING FROM N RANGE TO R, D, 3, 2
OR L RANGE...............................................................................................................................7A2-104
No. B6: ENGINE STARTER DOES NOT RUN IN P OR N RANGE...................................7A2-106
No. B7: ENGINE STARTER RUNS EXCEPT IN P OR N RANGE.....................................7A2-106
No. B8: EXTENDED TIME LAG WHEN SHIFT LEVER IS CHANGED TO N TO D........7A2-106
No. B9: EXTENDED TIME LAG WHEN SHIFT LEVER IS CHANGED TO N TO R........7A2-106
No. B10: BRAKE IS APPLIED IN R RANGE..........................................................................7A2-107
No. B11: INSUFFICIENT STARTING OR SHAKING IN D RANGE...................................7A2-107

7A2-22 DIAGNOSIS (JR405E)


6. If you select “continue”, you have to select “Model Year”, “Vehicle Type”.
7. After that, push button and turn Ignition switch tuned on, off, on following Tech-2 display. Tech-2 will read
information from controller after this procedure.
8. During obtaining information, Tech-2 is receiving information from the control unit ECM and TCM at the same
time. With VIN not being programmed into the new control unit at the time of shipment, "obtaining
information" is not complete (because the vehicle model, engine model and model year are specified from
VIN). For the procedure get additional information on vehicles, instruction will be provided in dialog form,
when TIS2000 is in operation.
9. Following instructions by Tech-2, push the "Exit" switch of Tech-2, turn off the ignition of the vehicle and turn
off the power of Tech-2, thereby removing from the vehicle.


3. Data Exchange
1. Connect Tech-2 to P/C, turn on the power and click the "Next" button of P/C.
2. Check VIN of the vehicle and choose "Next".
3. Select “Transmission” in the “System Type” selection.
4. When a lack of data is asked from among the following menu, enter accordingly.
Select following Menu

Model Year

Model

Engine type

Destination code (vehicles for general export)*1

* 1: How to read the destination code:
Destination code can be read from service ID Plate affixed on vehicle, while on service ID Plate the destination
code is described at the right-hand edge of Body Type line. In the figure, the destination code can be read as "RR3"
for Australia.