oil temperature ISUZU TF SERIES 2004 Manual Online

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

7A1-30 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.

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) 7A2-5
PAGE
NO. Z3: MODE LAMP (POWER DRIVE OR 3RD START) LIGHTS UP WHEN
THE POWER MODE OR 3RD START MODE IS TURNED OFF .................................. 7A2-137
NO. Z4: OIL TEMPERATURE WARNING LAMP LIGHTS UP ...................................... 7A2-137
NO. Z5: SELECT LEVER FEELING IS FAULTY. .......................................................... 7A2-137
NO. Z6: POOR FUEL CONSUMPTION ......................................................................... 7A2-138
NO. Z7: PATTERN SELECT SWITCH IS FAULTY........................................................ 7A2-138
NO. Z8: OIL IS SPLASHED DURING THE RUNNING .................................................. 7A2-138
NO. Z9: ABNORMAL SMELL ........................................................................................ 7A2-138
NO. Z10: ATF QUANTITY IS LOW OR HIGH ................................................................ 7A2-138
NO. Z11: ABNORMAL OIL PRESSURE........................................................................ 7A2-139
NO. Z12: REVERSE BUZZER DOES NOT RING .......................................................... 7A2-139
STALL TEST .................................................................................................................. 7A2-140
LINE PRESSURE TEST................................................................................................. 7A2-141
TIME LAG TEST............................................................................................................. 7A2-143
TEST DRIVE................................................................................................................... 7A2-144
SHIFT POINT CHART .................................................................................................... 7A2-147
SHIFT POINT DIAGRAM................................................................................................ 7A2-149
TCM VOLTAGE CHECK ................................................................................................ 7A2-154

7A2-12 DIAGNOSIS (JR405E)
F0: Diagnostic Trouble Code
F0: Read DTC Infor As Stored By ECU
F1: Clear DTC Information
F1: Data Display
F2: Snapshot
F3: Miscellaneous Test
F0: Lamp
F0: Power Lamp Test
F1: 3rd Start Lamp Test
F2: AT Oil Temperature Lamp Test
F3: Transmission Check Light Test
F1: Solenoids
F0: Low & Reverse Brake Solenoid
F1: 2-4 Brake Solenoid
F2: High Clutch Solenoid
F3: Low Clutch Solenoid
F4: Line Pressure Solenoid
F5: Lock Up Duty Solenoid
F4: Programming
F0: Program VIN
F1: Lock ECU

F0: Diagnostic Trouble Code
The purpose of the "Diagnostic Trouble Codes" mode is to
display stored trouble code in the TCM.
When "Clear DTC Information" is selected, a "Clear DTC
Information", warning screen appears. This screen informs you
that by cleaning DTC's "all stored DTC information in the TCM
will be erased".
After clearing codes, confirm system operation by test driving
the vehicle.

F1: Data Display
The purpose of the "Data Display" mode is to continuously
monitor data parameters.
The current actual values of all important sensors and signals
in the system are display through F1mode.
See the "Typical Scan Data" section.

F2: Snapshot
"Snapshot" allows you to focus on making the condition occur,
rather than trying to view all of the data in anticipation of the
fault. The snapshot will collect parameter information around a
trigger point that you select.

F3: Miscellaneous Test:
The purpose of "Miscellaneous Test" mode is to check for
correct operation of electronic system actuators.

F4: Programming (Factory Use Only):
The purpose of "Programming" is to program VIN in the ECM
and lock the programmed data.

7A2-14 DIAGNOSIS (JR405E)
MISCELLANEOUS TEST
The state of each circuit can be tested by using miscellaneous test menus. Especially when DTC cannot be
detected, a faulty circuit can be diagnosed by testing each circuit by means of these menus.
Even DTC has been detected, the circuit tests using these menus could help discriminate between a mechanical
trouble and an electrical trouble.

Connect Tech 2 and select "Powertrain", "JR 405E" & "Miscellaneous Test".
F0: Lamps
The circuit is normal if the warning light in the meter panel comes on and goes out in accordance with Tech 2
instruction.

Lamps

F0: Power Lamp Test
F1: 3rd Start Lamp Test
F2: AT Oil Tempeature Lamp Test
F3: Transmission Check Light Test


F0: Power Lamp Test


Power Lamp Test

Power Lamp Off



 Press "Active" key.
Then, "POWER DRIVE" indicator lamp is turned on in the meter panel.
 Press "Inactive" key.
Then, "POWER DRIVE" indicator lamp is turned off in the
meter panel.
 Press "Quit" Key to cancel the test.
F1: 3rd Start Lamp Test
F2: AT Oil Temperature Lamp Test
F3: Transmisstion Check Light Test
Test procedure is same as "F0: Power Lamp Test".
The circuit is normal if the warning light in the meter panel
comes on and goes out in accordance with Tech 2 instruction.

F1: Solenoids
The circuit is normal if clicking sound is generated in accordance with Tech 2 instruction.

Solenoids
F0: Low & Reverse Brake Solenoid
F1: 2-4 Brake Solenoid
F2: High Clutch Solenoid
F3: Low Clutch Solenoid
F4: Line Pressure Solenoid
F5: Lock Up Duty Solenoid

7A2-42 DIAGNOSIS (JR405E)
DTC P0710 (Flash Code 15) ATF Temperature Sensor Failure

ATF
Temp.
Sensor
TCM


B4 (+)



B14 (-)

H23 (8)



(3)
C95 (4)



(14)
BLU
Terminal
Assembly
BLU/BLKE54 (2)



(8)
BLU
BLU/BLK


Setting Condition:

The condition in which the voltage of oil temperature sensor is below 0.1V (146 C) and ATF temperature
warning lamp ON in the P or N range lasts for more than 5 minutes.
Or

The vehicle speed exceeds 20 km/h and the voltage of oil temperature sensor exceeds 2.43V (-40 C) for more
than 10 seconds.

Fail Safe:

The lock-up is inhibited, and TCM is controlled ATF temperature 80 C condition as substitute.

When the engine speed is more than 470 rpm for 10 minuets, the lock-up and gear shift to 4th (over-drive) are
allowed.

Possible Cause:

Oil temperature sensor wire open circuit or short circuit.

Oil temperature sensor malfunction.

Power supply wire open circuit, short circuit to battery or short circuit to ground between oil temperature sensor
and TCM terminal B4 (C95).

Ground wire open circuit or short circuit to battery between oil temperature sensor terminal and TCM terminal
B14 (C95).

Poor connection of each connector.

Reference:
Following output voltage and resistance can be measured by circuit tester.
Measurement terminal: B4 (C95) and B14 (C95)

ATF Temperature Output Voltage Resistance ATF Temperature Output Voltage Resistance
20
C
1.55V 2,500  80
C
0.5V 320 
40
C 1.08V 1,160  100
C
0.3V 190 
60
C
0.7V 590  120
C
0.2V 120 

DIAGNOSIS (JR405E) 7A2-91
SYMPTOM DIAGNOSIS

Symptom Condition Description
Oil Leak Breather Oil leaks from breather. J1
Between engine and converter housing Oil leaks between engine and converter
housing. J2
Between converter housing and main caseOil leaks between converter housing and
main case. J3
Between main case and rear housing Oil leaks between main case and rear
housing. J4
Oil pan Oil leaks from oil pan. J5
Manual shaft oil seal Oil leaks from manual shaft oil seal. J6
Oil cooler pipe Oil leaks from oil cooler pipe joint. J7
Other Transmission overheat You smell the transmission burning. Z1

The transmission smokes.
Mode lamp does not light up when the
power mode or 3rd start mode is turned on
The mode lamp on the instrument panel
does not light up though the power mode or
3rd start mode is turned on with the ignition
switch in ON position.
Z2
Mode lamp lights up when the power mode
or 3rd start mode is turned off
The mode lamp on the instrument panel
lights up though the power mode or 3rd start
mode is turned off with the ignition switch in
ON position.
Z3
Oil temperature warning lamp lights up Sometimes, the oil temperature warning
lamp lights up. Z4
Select lever feeling is faulty Select lever feeling is faulty. Z5
Poor fuel consumption Poor fuel consumption. Z6
Pattern select switch is faulty Shift pattern does not change though the
pattern select switch is turned on. Z7
Oil is splashed during the running Oil is splashed during the running. Z8
Abnormal smell Abnormal smell. Z9
Oil quantity is low or high Oil quantity is low or high. Z10
Abnormal oil pressure Oil pressure is low or high. Z11
Reverse buzzer does not ring Reverse buzzer does not ring in R range. Z12

7A2-124 DIAGNOSIS (JR405E)
No. E2: Only 4th gear (O/D) is Not Selectable

Description:

Gear is not shifted up from 3rd to 4th though the vehicle is accelerated.

Possible Cause:

Disordered select cable.

Disordered inhibitor switch.

ATF thermo sensor detects low oil temperature (4th gear is prohibited temperature less than 10C.).

Clogged oil passage of low clutch duty solenoid.

Trouble in control valve body (faulty operation, sticking, clogged oil passage).

Step Action Yes No
1 Dislocation or disordered of select lever.
Does the vehicle move when the brake is released in a position
other than the P range and the vehicle is pushed?
Go to Step 2
Adjust the select
cable.
2 Gear ratio trouble diagnosis.
Travel in the following sequence for about 7 seconds or more in
each range: Start in the L range (1st) to 2 range (2nd) to 3 range
(3rd) to D range (4th) (to detect the gear ratio trouble exactly, this
process should be carried out)
Go to Step 3 Go to Step 3
3 Are any DTCs stored?
Go to DTC Chart Go to Step 4
4 Are the quantity, contamination and smell normal?
If the ATF level is
low, replenish up to
the specified level.

Go to Step 5
If ATF is extremely
black and
contaminated and
smells burnt, slip of
the clutch is
supposed.
Overhaul the AT
unit.