sensor ISUZU KB P190 2007 Workshop Repair Manual

7A1-6 CONSTRUCTION AND FUNCTION
ELECTRONIC CONTROL COMPONENTS LOCATION
4WD Only 4W D 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
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
Accelerator pedal Position Sensor


Engine Control Module (ECM)
Data link connector
Select lever







Power Drive
, 3rd Start select switch

Figure 3. Electronic Control Components Location

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7A1-14 CONSTRUCTION AND FUNCTION
CONTROL VALVE
• Employing the direct electronic control (Direct Electronic Shift Control: DESC) for the clutch pressure has
simplified the oil pressure circuit, reduced the number of functional components and made the control
valve compact.
• The control valve body is divided into the upper body and the lower body. All solenoids, the oil pressure
switch and the ATF thermo sensor are installed to the lower body.
• Three-way valve type solenoids providing high responsibility are employed. Some of the solenoids are
switched between ON and OFF, and others repeat ON and OFF at 50Hz (duty cycle system).
Functionally, some supply output pressure when power is not supplied, and others drain the output
pressure.
• When the solenoid is driven based on the signal from the TCM, the oil pressure is changed.


Figure 22. Construction of Valve Body

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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

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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


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7A1-22 CONSTRUCTION AND FUNCTION
TURBINE SENSOR
• The turbine sensor is a hall element. It is installed to the front of the transmission case. The turbine
sensor converts the rotations of the reverse & high clutch drum fitted with the input shaft by spline to
pulse signal and sends the signal to the TCM.
• One turn of the reverse & high clutch drum generates 32-pulse signals, which are sent to the TCM.


Figure 38. Turbine Sensor

SPEED SENSOR
• The speed sensor is a hall element. It is installed to the rear of the transmission case. The speed sensor
converts the rotations of the parking gear, fitted with the output shaft by spline, to a pulse signal and
sends the signal to the TCM.
• One turn of the parking gear generates 16-pulse signals, which are sent to the TCM.


Figure 39. Speed Sensor Figure 40. Location of Turbine & Speed Sensor



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CONSTRUCTION AND FUNCTION 7A1-23
ACCELERATOR PEDAL POSITION SENSOR
• Opening of the accelerator pedal is converted to an electric signal which is transmitted from ECM to TCM.
• The accelerator pedal position sensor (1) is installed to the accelerator pedal.





Pin
No. W ire Color
Pin Function
1 BLU APP Sensor 3 +5V Reference
2 Not Used
3 ORN/BLU APP Sensor 2 Low Reference
4 BLK APP Sensor 1 Low Reference
5 RED APP Sensor 1 Signal
6 BLU/W HT APP Sensor 3 Signal
7 BLU/RED APP Sensor 3 Low Reference
8 ORN APP Sensor 2 +5V Reference
9 BLU/GRN APP Sensor 2 Signal
10 W HT APP Sensor 1 +5V Reference
RTW 77ASH000501
Figure 41. Accelerator Pedal Position Sensor
Figure 42. Pin Assignment

ENGINE SPEED SENSOR (=CKP SENSOR)
• The engine speed sensor converts the crankshaft from the Crankshaft Position (CKP) sensor rotation to a
pulse signal which is transmitted from ECM to TCM.








Pin
No. W ire Color
Pin Function
1 YEL Sensor Signal
2 BLU Sensor Low Reference
3 GRN Sensor +5V Feed
Figure 43. Crankshaft Position (CKP) Sensor Figure 44. Pin Assignment



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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

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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.

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

Control item

Item

Line
pressure control
Gear shift
control
Shift
pattern
selection
Lock-up control Direct
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 (4W D Only)

ATF thermo sensor
High clutch oil pressure switch

2-4 brake oil pressure switch
Low & Reverse brake oil pressure
switch
Input
Accelerator Pedal 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



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CONSTRUCTION AND FUNCTION 7A1-31
As a result, the lock-up piston is fitted slowly to the converter cover under pressure securing smooth lock-
up engagement.


Figure 51. Lock-up Control

DIRECT ELECTRIC SHIFT CONTROL (DESC)
Feature
• Based on each switch signal (low & reverse brake pressure, 2-4 brake pressure & high clutch pressure)
and each sensor signal (turbine sensor, speed sensor, engine speed signal & APP position signal), the
duty cycle type solenoid adjusts the clutch pressure to match the engine load and vehicle travel
conditions. Controlling the engagement and disengagement of the clutch and brake pressure is directly
and accurately controlled via TCM, which is different to the previous accumulator type.
Operation
• Instead of the previous system (on/off type of shift solenoid and shift valve), the combination of the duty
cycle type solenoid and the amplifier (Amp) valve are used to adjust the clutch pressure to match the
engine load and vehicle travel conditions, based on the signal from the TCM. Also, the pressure switch
provided in the oil passage of the control valve transmits the oil pressure condition (at that time) to TCM,
enabling the engagement and disengagement control of the clutch and brake to be directly and finely
carried out.
• 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
pressures on the engagement side and disengagement side are simultaneously controlled.
As a result, engine racing or clutch drag is prevented which enables a smooth and quick shift response.


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