4WD ISUZU TF SERIES 2004 Workshop Manual

CONSTRUCTION AND FUNCTION 7A1-29
CONTROL ITEM, INPUT AND OUTPUT

Control item


Item

Line
pressure
control
Gear
shift
control
Shift
pattern
selection
Lock-up
controlDirect
electronic
shift
control
(DECS)
Learning
control
Fail-safe
function
Self-
diagnosis
function
Speed sensor
Turbine sensor
Engine speed sensor
Brake switch

Inhibitor switch
Mode select switch

4L switch (4WD Only)

ATF thermo sensor
High clutch oil pressure switch

2-4 brake oil pressure switch

Low & Reverse brake oil pressure
switch
Input
Throttle position sensor
Line pressure solenoid
Low clutch solenoid

High clutch solenoid

2-4 brake solenoid

Low & Reverse brake solenoid

Lock-up solenoid

Shift pattern indicator lamp

ATF temperature indicator lamp

Output
Check trans indicator lamp

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

DIAGNOSIS (JR405E) 7A2-155
No. Wire
Color Pin Name Input /
OutputConnected toMeasurement
Item Measurement
Condition StandardInspection
Point at
Trouble
Related
harness
Engine
Speed
Sensor A7 BLK/
RED Engine Speed Sensor Input ECM Voltage (Wave
form) At 2000rpm.
Circuit tester
(+) to A7 pin,
(-) to B5 pin. Pulse
generated (At
AC range
approx. 6.2V)
ECM
A8 - - - - - - - -
A9 - - - - - - - -
Related
harness
Speed
sensor
Speed meter
A10 BLK/
YEL Vehicle Speed Sensor Out (2WD Only) Output Speed meter Voltage (Wave
form) At run in L
range in 1st
gear 20 km/h.
Circuit tester
(+) to A10 pin,
(-) to B5 pin. Pulse
generated (At
AC range
approx. 6.5V)
TCM
At switch
pushed Less than 2VRelated
harness
A11 GRN/
WHT 3rd Start Select Switch Input 3rd start switch Voltage
At switch off 10 – 14.5V 3rd start
switch
At 4L Less than 2VRelated
harness
A12 BLU/
WHT 4L Mode Switch (4WD Only) InputTransfer control
unit Voltage
At other than
4L 10 – 14.5V 4L switch
A13 - - - - - - - -
A14 - - - - - - - -
A15 - - - - - - - -
At fully close Off duty 10%Related
harness
ECM A16 RED/
WHT Throttle Position Sensor Input ECM Wave form
(140Hz Duty
signal) *1
At fully open Off duty 90%Throttle
position
sensor
At 3 range 10 – 14.5V Related
harness
A17 BLK/
GRN 3 Range Switch Input Inhibitor switch Voltage
At other than
3 range Less than 2VInhibitor
switch
At key switch
ON 10 – 14.5V Related
harness
A18 YEL/
BLK DIAG Switch InputData link
connector Voltage
At short circuit
of DIAG
switch Less than 2VRelated
harness
At lamp OFF 10 – 14.5V Related
harness A19 ORG/
BLU A/T OIL TEMP Indicator Lamp OutputAT OIL TEMP
indicator lamp Voltage
At lamp ON Less than 2V Lamp
At lamp OFF 10 – 14.5V Related
harness A20 GRN/
YEL CHECK TRANS Indicator Lamp OutputCHECK TRANS
indicator Lamp Voltage
At lamp ON Less than 2V Lamp
At lamp OFF 10 – 14.5V Related
harness A21 PNK POWER DRIVE Indicator Lamp OutputPOWER DRIVE
indicator lamp Voltage
At lamp ON Less than 2V Lamp
A22 - - - - - - - -
A23 - - - - - - - -

7A4-8 UNIT REPAIR (JR405E)

25ASSY019



Remove the 2-4 brake retainer and return spring.



26ASSY026

14.Carrier assembly (Carrier and low clutch assembly),
bearing, bearing race, and 2 – 4 brake assembly

Pull the carrier assembly, the bearing, the bearing race
and the 2-4 brake assembly (Dish plate, retaining plate,
drive plate, and driven plate) from the transmission case
at the same time.

Remove the bearing, the bearing race, and the 2-4
brake assembly from the carrier assembly.



27U-SPG02



Remove the 3 brake springs from the transmission case.



28L&R06

15.Low and reverse brake

Remove the snap ring.

Pull the low and reverse brake free.


16.Rear extension (2WD) or Adapter case (4WD)

Rotate the transmission case so that the oil pan opening
is facing up.

Remove the 10 bolts and the rear extension (2WD) o
r
the adapter case (4WD).

7A4-80 UNIT REPAIR (JR405E)

40ASSY091



Push the output shaft into place.


19.Rear extension (2WD) or adapter case (4WD)

Use the oil seal installer to install the oil seal to the rea
r
extension (2WD) or adapter case (4WD).
Oil seal installer:
5-8840-2769-0 (2WD)
5-8840-2770-0 (4WD)

41ASSY096



Install the bearing (with bearing race) to the rear
extension (2WD) or adapter case (4WD).
NOTE:







The black side (bearing race) of the bearing must be
visible.







Apply Vaseline to the bearing.




249L300005



Apply sealing agent (TB1216B) to the rear extension
(2WD) or adapter case (4WD) contact surfaces.



249L300006

Install the rear extension (2WD) or adapter case (4WD)
to the transmission case and tighten the 10 bolts to the
specified torque.
Torque: 53 N 


m (39 Ib 


ft)