Page 4263 of 6020
7A1-24 CONSTRUCTION AND FUNCTION
BRAKE SWITCH
• The brake switch (1) is installed to the brake pedal (2). When the driver steps on the brake pedal, an
electric signal is sent to the TCM.
TCM A3 +12V
RTW 77ASH000601
Figure 45. Brake Switch
Figure 46. Pin Assignment
MODE SELECT SWITCH
• The mode select switch (2) is installed beside the select lever (1). When the driver selects the PWR or
3rd, an electric signal is sent. It turns ON the indicator lamp in the meter.
• The 3rd START mode can only be used in the D position.
Power 3rd Illumination
Lamp
1 (Illumination)
2 (Ground)
3 (TCM A24)
4 (No Connection)
5 (TCM A11)
6 (Ground)
21
65 4 3
RTW 77ASH000701
Figure 47. Mode Select Switch
Figure 48. Pin Assignment
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ISUZU KB P190 2007
Page 4264 of 6020

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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ISUZU KB P190 2007
Page 4267 of 6020

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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Page 4268 of 6020
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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Page 4273 of 6020

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 operation 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 (4W D 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 sends signal to TCM.
Accelerator Pedal 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 conditions based on a signal from
TCM.
Low clutch solenoid Selects appropriate gear shifting position for current driving
conditions and regulates low clutch supply oil pressure based
on a signal from TCM.
High clutch solenoid Selects appropriate gear shifting position for current driving
conditions and regulates high clutch supply oil pressure based
on a signal from TCM.
2-4 brake solenoid Selects appropriate gear shifting position for current driving
conditions and regulates 2-4 brake supply oil pressure based
on a signal from TCM.
Low & Reverse brake solenoid Selects appropriate gear shifting position for current driving
conditions and regulates low & reverse brake supply oil
pressure based on a signal from TCM.
Lock-up solenoid Regulates lock-up pressure to appropriate level for current
driving conditions based on a signal from TCM.
Mode indicator lamp Indicates POW ER DRIVE or 3rd START switch position.
Speed meter signal (2W D Only) Outputs vehicle speed to the 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.
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Page 4274 of 6020
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
(4W D 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 (2W D
Only)
Power, 3rd start indicator
lamp
Check trans indicator
lamp
Data link connector Self-diagnosis
function
Transmission
Control
Module (TCM)
4L mode
Tachometer
signal output
APP PW M
position signal
output
Figure 54. Control Circuit Block Diagram
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ISUZU KB P190 2007
Page 4295 of 6020
TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-11
TR Switch and Indicator Lamps
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Page 4381 of 6020

TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-97
Faulty Operation in Stopping Vehicle moves in P range or parking is not disengaged in other than Prange G1
Large creeping force G2
Small creeping force G3
Large noise during idle with vehicle stop G4
Faulty Lock Up Judder Occurs at Lock Up H1
Large Shock at Lock Up H2
Lock Up Point is High or Low H3
No Lock Up No Lock Up I1
Transmission Fluid Leak Transmission fluid leaks from breather J1
Transmission fluid leaks between engine and converter housing J2
Transmission fluid leaks between converter housing and transmission
case J3
Transmission fluid leaks between transmission case and extension
housing J4
Transmission fluid leaks from oil pan J5
Transmission fluid leaks from manual shaft oil seal J6
Transmission fluid leaks from oil cooler pipe joint J7
Others Transmission overheat Z1
Mode lamp (power drive or 3rd start) does not turn On Z2
Mode lamp (power drive or 3rd start) does not turn Off Z3
A/T oil temperature lamp turns On Z4
Selector lever feeling is faulty Z5
Poor fuel consumption Z6
Shift indicator is faulty Z7
Abnormal smell Z8
Transmission fluid quantity is low or high Z9
Transmission fluid quantity is low or high Z10
Abnormal transmission fluid pressure Z11
Diagnostic Category
Category No.
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ISUZU KB P190 2007