2007 ISUZU KB P190 oil

CONSTRUCTION AND FUNCTION 7A1-17

ATF Thermo Sensor • The ATF thermo sensor detects the ATF temperature in the oil pan and sends a signal to the TCM.
• The ATF thermo sensor is of the thermister type and the resistance value changes according to the ATF
oil temperature.
• When the ATF temperature is cold, the sensor resistance is high. When the ATF temperature increases,
the sensor resistance decreases.
• When the ATF temperature increases to 135 °C (275 °F), the TCM lights up the ATF temperature warning
lamp in the meter. When the ATF temperature decreases below 125 °C (257 °F), the ATF temperature
warning lamp switches off.
• The ATF thermo sensor is installed to the lower control valve body and integrated with the harness
assembly.













10.0
100.0
1,000.0
10,000.0
100,000.0
-30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 A TF Temp er a t ur e ( °C)
Resistance (Ω
)
Figure 29. Characteristic of Thermo Sensor


Figure 30. Location of Thermo Sensor
ATF Temperature
(deg. C) Resistance (Ohm)
(Approximately) ATF Temperature
(deg. C) Resistance (Ohm)
(Approximately)
-30 29,614 100190
-20 16,705 110149
-10 9,842 120118
0 6,028 128 98
20 2,500 130 94
40 1,160 135 84
50 819 140 76
60 591 14568
80 324 15062

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

7A1-18 CONSTRUCTION AND FUNCTION
Terminal Assembly Pin No. Connected to Connected TCMPin No.
6 Line Pressure Solenoid B23
12 Low & Reverse Brake Oil Pressure Switch B12
5 Low & Reverse Brake Duty Solenoid B6
11 Ground Return B22
4 Lock-up Duty Solenoid B17
10 High Clutch Duty Solenoid B8
3 Low Clutch Duty Solenoid B9
9 2-4 Brake Duty Solenoid B7
2 Oil Thermo Sensor B4
8 Oil Thermo Sensor Ground B14
1 High Clutch Oil Pressure Switch B20
7 2-4 Brake Oil Pressure Switch B1


123456
891011127

Terminal AssemblyInhibitor Switch
Figure 31. Pin Assignment Figure 32. Location of Terminal Assembly


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

CONSTRUCTION AND FUNCTION 7A1-19

OIL PASSAGE



Figure 33. Oil Passage of Transmission Case

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

7A1-20 CONSTRUCTION AND FUNCTION


Figure 34. Oil Passage of Oil Pump

PARKING FUNCTION
• By setting the select lever to the P position, the parking pawl is engaged with the parking gear and fixes
the output shaft.
• By moving the select lever, the manual shaft on the right side of the AT is moved. The manual plate and
parking rod in the AT are interlocked with the manual shaft. When the manual shaft moves, the parking
rod end pushes up the parking pawl.
• The parking pawl is engaged with the parking gear when pushed up, and fixes the output shaft.
• When the clutch is disengaged, it returns to the original position via the force of the return spring, fixed to
the parking pawl.


Figure 35. Parking Function


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

CONSTRUCTION AND FUNCTION 7A1-25
TRANSMISSION CONTROL MODULE (TCM)
• The TCM is fitted on the side of the brake pedal via two stud bolts.
• The TCM judges the line pressure, gear shifting point and lock-up operation based on electrical signals
from switches and sensors, and sends the appropriate signals to solenoids.





B9 B8 B7 B6 B5 B4 B3 B2 B1 A9 A8 A7 A6 A5 A4 A3 A2 A1
B18 B17 B16 B15 B14 B13 B12 B11 B10 A18 A17 A16 A15 A14 A13 A12 A11 A10
B24 B23 B22 B21 B20 B19 A24 A23 A22 A21 A20 A19
Connect to White Connector Connect to Grey Connector


Figure 49. Pin Assignment

Pin No. Pin Assignment Pin No.Pin Assignment
B1 2-4 Brake Oil Pressure Switch A1 V BATT (Battery Back-up Power Supply)
B2 2 Position Switch A2 P Position Switch
B3 Turbine Sensor A3 Brake Switch
B4 ATF Thermo Sensor A4 3rd Start Indicator Lamp
B5 Ground A5 K-Line Signal (Tech 2 Serial Communication)
B6 Low & Reverse Brake Duty Solenoid A6 No Connection
B7 2-4 Brake Duty Solenoid A7 Engine Speed Sensor
B8 High Clutch Duty Solenoid A8 No Connection
B9 Low Clutch Duty Solenoid A9 No Connection
B10 N Position Switch A10 Vehicle Speed Sensor Out (2W D Only)
B11 D Position Switch A11 3rd START Select Switch
B12 Low & Reverse Brake Oil Pressure Switch A12 4L Mode Switch (4W D Only)
B13 Vehicle Speed Sensor A13 No Connection
B14 ATF Thermo Sensor Ground A14 No Connection
B15 No Connection A15 No Connection
B16 No Connection A16 Accelerator Pedal Position Sensor
B17 Lock-up Duty Solenoid A17 3 Position Switch
B18 Vign (Ignition Power Supply) A18 DIAG Switch (Test Switch)
B19 R Position Switch A19 A/T OIL TEMP Indicator Lamp
B20 High Clutch Oil Pressure Switch A20 CHECK TRANS Indicator Lamp
B21 L Position Switch A21 POW ER DRIVE Indicator Lamp
B22 Ground (Shift Solenoid) A22 No Connection
B23 Line Pressure Solenoid A23 No Connection
B24 Vign (Ignition Power Supply) A24 POW ER DRIVE Select Switch

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

7A1-26 CONSTRUCTION AND FUNCTION
CONTROL MECHANISM
CONTENT OF FUNCTION AND CONTROL
Item Description
Line pressure control TCM issues a signal according to vehicle travel, engine load and other conditions, which
drives the ON/OFF type line pressure solenoid 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 position (D, 3, 2, L position), the line pressure decreases lower than
that in the P, N, and R position through the oil pressure circuit.


Gear shift control The TCM issues a shift solenoid drive signal based on the traveling mode switch, inhibitor
switch, the vehicle speed, the APP opening and other input signals, to control the optimum
gear position automatically.
Shift features have been set up to the TCM; the normal mode is suited to normal travel, and
the power mode is used when the vehicle is loaded or the speed accelerated.
In addition, shift features used only for high oil temperature, hill climbing, and downward
travel have been set up to the TCM. These are automatically switched depending on the
travel conditions.
W hen the oil temperature is low (10°C or less), shifting up from the third speed to the fourth
speed is prohibited by the gear shift control.


Shift pattern selection
control
The TCM selects the following shift pattern according to a vehicle condition.

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

Up Slope
Low Normal



OFF
OFF
- High temperature mode -
High temperature mode setting condition
ATF temperature: 122 °C or more
Above condition is met for 10.16 seconds.
High temperature mode cancel condition
ATF temperature: 115 °C or less
Above condition is met for 10.16 seconds.

-NOTE-
High temperature mode may be activated with driving conditions other than the setting
conditions stated, in order to protect Automatic Transmission from thermal damage.

- 3rd start mode -
3rd start mode setting condition
3rd start switch: On → Off (Pushed)
Vehicle speed: 11km/h or less.
ATF temperature: 115 °C or less.
APP position: 8% or less.
Select lever position: D position
Above conditions are all met at the same time.




BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

CONSTRUCTION AND FUNCTION 7A1-27
Item Description
3rd start mode reset condition
3rd start switch: On → Off again(Pushed again)
Vehicle speed: 34km/h or more
Select lever position: Other than D position
At least, one of above conditions is met.

- 4L mode -
4L mode setting condition
4L switch: On
Vehicle speed: 5km/h or more
Above conditions are all met at the same time.
4L mode reset condition
4L switch: Off
Vehicle speed: Less than 5km/h
Above conditions are all met at the same time.

- Down slope mode -
Down slope mode setting condition
Brake switch: On
Accelerator pedal condition: Released for 2 seconds or more.
Select lever position: D or 3 position
Vehicle speed: More than 60km/h
Increment of vehicle speed: More than 1km/h per second
Above conditions are all met at the same time.
Down slope mode reset condition
Accelerator pedal condition: Depressed
Select lever position: Other than D or 3 position
At least, one of above conditions is met.

- Power Mode -
W hen the power drive switch is On the shift pattern 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 APP angle and the average
acceleration. Otherwise, up-slope reasoning value is calculated from the vehicle speed.
TCM chooses up-slope mode when the former is bigger than the latter.


Lock-up control The lock-up solenoid adjusts the pressure to control the lock-up according to the signal
from the TCM. This signal is based on the vehicle speed, APP opening and other input
signals based on the pre-set lock-up point.
Smooth lock-up control engages and disengages the clutch smoothly at the time of lock-up.
W hen the oil temperature is low (20°C or less), lock-up is prohibited even when the vehicle
is at a lock-up speed.
The lock-up is also disengaged when the APP 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 suit 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, which controls the disengagement or engagement of the
clutch and brake directly and finely.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

7A1-28 CONSTRUCTION AND FUNCTION
Item Description
Learning function The learning function is provided 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 shift time closer to
the value pre-set to the TCM.
Fail-safe function In the case of a malfunction of the vehicle speed sensor, APP sensor, all solenoids or the
inhibitor switch, TCM automatically begins fail-safe control to minimize effects on driving.
The gear is fixed in 3rd gear and the power supply to the solenoid is shut off so that the
solenoid does not work. Lock up clutch is disengaged in this mode.
Self-diagnosis function Parts required for controlling the automatic transmission are provided with a self-diagnosis
function. W hen any trouble occurs, the check trans indicator lamp blinks to warn the driver.
The trouble code is memorized in the TCM.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007