ISUZU KB P190 2007 Workshop Repair Manual

TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-157
Down Slope Mode
Condition for setting the down slope mode shift map;
All of the following conditions are met:
• Brake pedal switch is depressed
• Accelerator pedal is released
• Vehicle speed is more than 60 km/h (36 MPH)
• Increment of vehicle speed is more than 1 km/h (1 MPH) per second
• Selector lever is D or 3 range
Condition for canceling the down slope mode shift map;
Either of the following condition is met:
• Accelerator pedal is depressed
• Selector lever is other than D or 3 range Power Drive Mode
When the power drive switch is ON, the TCM switches
shift map to the power drive mode map and performs
gearshift control from 1st to 4th to gain more
acceleration compared with normal mode.
Up Slope Mode
Up slope reasoning value is calculated from the
averaged accelerator pedal angle and the averaged
acceleration. Otherwise, up slope reasoning value is
calculated from the vehicle speed. The TCM selects a
up slope mode when the former is bigger than the
latter.
Lock Up Control
Legend 1. TCC solenoid valve
2. Solenoid fluid pressure
3. Lock up control spool valve
4. Torque converter clutch (TCC) 5. Torque converter front cover
6. TCC engagement fluid pressure
7. TCC disengagement fluid pressure
TCM
Sensor inputs
Input shaft speed (ISS) sensor
Output shaft speed (OSS) sensor
Transmission fluid temperature (TFT) sensor
Accelerator pedal position signal (via ECM)
Engine speed signal (via ECM)
Solenoid valve outputsTorque converter clutch (TCC) solenoid valve

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ISUZU KB P190 2007

7A2-158 TRANSMISSION CONTROL SYSTEM (JR405E)
The TCM controls the torque converter clutch (TCC)
solenoid valve based on the accelerator pedal angle,
input shaft speed, output shaft speed and transmission
fluid temperature.
Smooth lock up control is employed to engage or
disengage the TCC smoothly at the time of lock up On
or Off. When the TCM determines the TCC
engagement, the solenoid valve control duty cycle
(pulse width modulation [PWM]) signal is gradually
increased (5% to 95%) and the transmission fluid
between the TCC piston and torque converter front
cover is gradually drained. As a result, the TCC piston
is fitted slowly to the torque converter front cover under
fluid pressure securing smooth lock up engagement. The lock up control does not start when the
transmission fluid temperature is less than 20 °C (68 °F)
even though the vehicle is at the lock up control speed
area. The lock up control disengages when the
accelerator pedal angle is released.
Direct Electronic Shift Control (DECS)
Legend 1. Oil pump
2. Pressure regulator spool valve
3. ON/ OFF type solenoid valve (pressure control [PC]
solenoid valve 4. Duty cycle type solenoid valve (shift solenoid valve)
5. Amplifier (AMP) valve
6. Clutch
Solenoid valve outputs
Pressure control (PC) solenoid valve
Low & reverse brake solenoid valve
2-4 brake solenoid valve
High clutch solenoid valve
Low clutch solenoid valve
TCM
Sensor inputsInput shaft speed (ISS) sensor
Output shaft speed (OSS) sensor
Transmission fluid temperature (TFT) sensor
Accelerator pedal position signal (via ECM)
Engine speed signal (via ECM)
Switch inputs
Low & reverse brake transmission fluid
pressure (TFP) switch
2-4 brake transmission fluid pressure (TFP)
switch
High clutch transmission fluid pressure (TFP)
switch

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TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-159
Based on each transmission fluid pressure (TFP)
switch signal and each speed sensor signal and the
accelerator pedal angle, the duty cycle type shift
solenoid valve adjusts the clutch pressure to match the
engine load and vehicle running conditions. Controlling
the engagement and disengagement of the clutch and
brake pressure is directly and accurately controlled via
TCM, which is different to the conventional accumulator
type. Instead of the conventional system (On/ Off type
shift solenoid valve and shift valve), the combination of
the duty cycle type solenoid valve and the amplifier
(AMP) valve are used to adjust the clutch pressure to
match the engine load and vehicle driving conditions,
based on the signal from the TCM. Also, the TFP
switch provided in the fluid passage of the control valve
transmits to TCM, enabling the engagement and
disengagement control of the clutch and brake to be
directly and finely. When the gear is shifted from the
2nd to 3rd, 3rd to 4th, 4th 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.
Learning Control
Solenoid valve outputs
Low & reverse brake solenoid valve
2-4 brake solenoid valve
High clutch solenoid valve
Low clutch solenoid valve
TCM
Sensor inputs Input shaft speed (ISS) sensor
Output shaft speed (OSS) sensor
Transmission fluid temperature (TFT) sensor
Accelerator pedal position signal (via ECM)
Engine speed signal (via ECM)
Switch inputs
Low & reverse brake transmission fluid
pressure (TFP) switch
2-4 brake transmission fluid pressure (TFP)
switch
High clutch transmission fluid pressure (TFP)
switch

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7A2-160 TRANSMISSION CONTROL SYSTEM (JR405E)
Legend1. Input shaft speed
2. Transmission fluid pressure
3. Time
4. Clutch engagement fluid pressure 5. Engine speed
6. Disengagement side clutch fluid pressure
7. Engagement side clutch fluid pressure
Transmission fluid pressure control timing is optimally
corrected at the time of clutch engagement and
disengagement. It is controlled to bring the shift time to
the value preset to the TCM, and compensate for the
changes in engine performance and transmission
characteristics. When the gear is shifted, the clutch
pressure (B) is optimally corrected so that the shift time
(A) is as close to the target value preset to the TCM.
The variation in the engine performance and changes
to transmission characteristics which occur with time,
can be compensated for based on the past shift results.
When the clutch is operated to shift the gear, the time
of the clutch fluid pressure release (D) on the
disengagement side is optimally corrected so that the
change of the engine speed (C) is optimum.
Notice: When the battery terminal is disconnected, the
contents of learning are cleared and as a result the shift
shock may increase. After the vehicle has traveled,
learning is repeated and the shock decreases
gradually.

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TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-161
Transmission Power Flow Description
Legend1. Input shaft
2. Front planetary carrier
3. Front pinion gear
4. Front sun gear
5. Rear sun gear
6. Rear pinion gear
7. Rear internal gear
8. Output shaft
9. Reverse clutch 10. 2-4 brake
11. High clutch
12. Front internal gear
13. Rear planetary carrier
14. Low clutch
15. Low & reverse brake
16. Low one-way clutch
17. Parking pawl
Construction Parts
The JR405E consists of two sets of planetary gears,
three multiple plate clutches, two multiple plate brakes
and one one-way clutch.
High Clutch
High clutch (11) connects the input shaft (1) to the front
planetary carrier (2). It is engaged at 3rd and 4th gear.
Low Clutch
Low clutch (14) connects the front planetary carrier (2)
to the rear internal gear (7). It is engaged at 1st, 2nd
and 3rd gear.
Reverse Clutch
Reverse clutch (9) connects the input shaft (1) to the
front sun gear (4). It is engaged at reverse gear.
Low One-way Clutch
Low one-way clutch (16) allows the front planetary
carrier (2) to turn forward (clockwise) but locks to
opposite direction (counterclockwise). It is operative
when accelerating.
Low & Reverse Brake
Low & reverse brake (15) locks the front planetary
carrier (2). It is engaged in L range and reverse gear. 2-4 Brake
2-4 brake (10) locks the front sun gear (4). It is
engaged at 2nd and 4th (O/D) gear.

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7A2-162 TRANSMISSION CONTROL SYSTEM (JR405E)
Parking
Legend1. Input shaft
2. Front planetary carrier
3. Front pinion gear
4. Front sun gear
5. Rear sun gear
6. Rear pinion gear
7. Rear internal gear
8. Output shaft
9. Reverse clutch 10. 2-4 brake
11 . H i g h c l u t c h
12. Front internal gear
13. Rear planetary carrier
14. Low clutch
15. Low & reverse brake
16. Low one-way clutch
17. Parking pawl
Although the driving force of the input shaft (1) is
transmitted to the rear sun gear (5) and reverse & high
clutch drum, the driving force is not transmitted to the
output shaft (8) since all of the clutches and brakes are
not engaged. Therefore, the vehicle can move in this
condition. However, since the output shaft (8) is
mechanically locked with the parking pawl (17), the rear
planetary carrier (13) and front internal gear (12) are
locked. For this reason, the vehicle does not move.

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TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-163
Neutral
Legend1. Input shaft
2. Front planetary carrier
3. Front pinion gear
4. Front sun gear
5. Rear sun gear
6. Rear pinion gear
7. Rear internal gear
8. Output shaft
9. Reverse clutch 10. 2-4 brake
11. High clutch
12. Front internal gear
13. Rear planetary carrier
14. Low clutch
15. Low & reverse brake
16. Low one-way clutch
17. Parking pawl
Although the driving force of the input shaft (1) is
transmitted to the rear sun gear (5) and reverse & high
clutch drum, the driving force is not transmitted to the
output shaft (8) since all of the clutches and brakes are
not engaged. Therefore, the vehicle can move in this
condition.

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7A2-164 TRANSMISSION CONTROL SYSTEM (JR405E)
Reverse Gear
Legend1. Input shaft
2. Front planetary carrier
3. Front pinion gear
4. Front sun gear
5. Rear sun gear
6. Rear pinion gear
7. Rear internal gear
8. Output shaft
9. Reverse clutch 10. 2-4 brake
11 . H i g h c l u t c h
12. Front internal gear
13. Rear planetary carrier
14. Low clutch
15. Low & reverse brake
16. Low one-way clutch
17. Parking pawl
The driving force from the input shaft (1) is transmitted
to the rear sun gear (5) and reverse & high clutch drum.
In the R range, the reverse clutch (9) is engaged and
the driving force is transmitted to the front sun gear (4)
and rotates it clockwise. The low & reverse brake (15)
is also engaged and the front planetary carrier (2) is
fixed so that the front pinion gear (3) does not rotate
clockwise, but can rotate counterclockwise. As a result,
the output shaft (8) rotates counterclockwise and the
vehicle goes backwards.

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TRANSMISSION CONTROL SYSTEM (JR405E) 7A2-165
First Gear In D, 3, 2 Range
Legend1. Input shaft
2. Front planetary carrier
3. Front pinion gear
4. Front sun gear
5. Rear sun gear
6. Rear pinion gear
7. Rear internal gear
8. Output shaft
9. Reverse clutch 10. 2-4 brake
11. High clutch
12. Front internal gear
13. Rear planetary carrier
14. Low clutch
15. Low & reverse brake
16. Low one-way clutch
17. Parking pawl
The driving force from the input shaft (1) is transmitted
to the rear sun gear (5) and reverse & high clutch drum.
As the low clutch (14) is engaged, the movement of the
rear internal gear (7) is restricted. Since the low one-
way clutch (16) acts at the same time,
counterclockwise rotations of the rear internal gear (7)
are locked. As a result, the driving force transmitted to
the rear sun gear (5) rotates the rear planetary carrier
(13) clockwise, then the rotation speed is decreased
and multiple forces is transmitted to the output shaft (8). When decelerating, the rotating speed of the rear
planetary carrier (13) (rear pinion gear [6]) is higher
than that of the rear sun gear (5) and the rear internal
gear (7) attempts to rotate clockwise. At this time, the
low one-way clutch (16) does not act but races, and
therefore the rear internal gear (7) rotates clockwise.
The reverse torque from the driving shaft is not
transmitted to the engine side and the engine brake
does not act.

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7A2-166 TRANSMISSION CONTROL SYSTEM (JR405E)
First Gear In L Range
Legend1. Input shaft
2. Front planetary carrier
3. Front pinion gear
4. Front sun gear
5. Rear sun gear
6. Rear pinion gear
7. Rear internal gear
8. Output shaft
9. Reverse clutch 10. 2-4 brake
11 . H i g h c l u t c h
12. Front internal gear
13. Rear planetary carrier
14. Low clutch
15. Low & reverse brake
16. Low one-way clutch
17. Parking pawl
The basic mechanism is the same as in the D, 3, and 2
ranges. To apply the engine brake, the low & reverse
brake (15) is engaged to restrict the movement of the
low one-way clutch (16).
When decelerating, as the rear internal gear (7) is
fixed, reverse torque from the propeller shaft is
transmitted to the engine side so that the engine brake
is applied.

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