indicator ISUZU KB P190 2007 Workshop Repair Manual

7D1-4 TRANSFER CONTROL SYSTEM

Summary of transfer control system
The transfer control system switches between the 2-wheel
drive (2H), 4-wheel drive high-speed (4H), 4-wheel drive low-
speed (4L), and neutral positions electrically when the driver
operates the switches.
This system has following functions.
1. Connection or disconnection of drive force distribution to the
front wheel front shaft (axle shaft). (The drive force
distribution to the front propeller is connected o
r
disconnected with the motor actuator.)
2. Try to repeat the connection or disconnection of the front wheel drive function as described above.
3. Option: Shift on the fly type only.
Instruction of connection or disconnection of the drive force transmission between the front wheel axle (axle shaft) and
front wheel. (The motor actuator connects or disconnects
the left front wheel and front wheel axle (axle shaft).)
4. Shifting of auxiliary transmission gears, connection o
r
disconnection of wheel and engine drive force (4H, 4L,
neutral).
5. Operation of the indicator on the instrument panel.
6. Transmission of the position signal to other controllers.


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7D1-6 TRANSFER CONTROL SYSTEM
the 4×2 - 4 ×4 shift rod. W hen moving in 4 ×2 direction, a spring
standby mechanism is provided between the rod and sleeve so
that the rod is positioned at the 4 ×2 position, while the sleeve is
at the 4 ×4 position.
This mechanism is provided to protect the shift mechanism
from the force and to prevent movement of the sleeve
(torsional torque etc. of the drive system). By releasing the
preventive force, the sleeve can move to the 4 ×2 state by the
spring force.

Neutral switch
The neutral switch detects the movement of the shift rod
driving the high-low sleeve.
PUSH close is achieved with the PUSH close switch when the
shift rod is positioned between the High and the Low, at the
neutral state.

High-Low Sleeve & Arm
The spring standby mechanism is provided for the high-low
sleeve in both directions of the high-low shift rod. Therefore,
the rod position and the actual sleeve position may be offset in
some cases.
This system is provided to protect the shift mechanism from a
collision due to coincidence of the high and low phases of the
engaged splines. By giving rotational force to the preventing
phase coincidence, the splines are moved to the proper
engagement position by the spring force.

Shift actuator
The output shaft is rotated by the built-in motor and the transfer
position is switched.
Detection (limit) switches to detect the rotating angle of the
output shaft that is provided to the actuator at 4 positions.
These are connected to the transfer controller through the
vehicle harness to constantly transmit the actuator operating
angle and changes in its transfer status.

7B4-PDF2
4WD indicator (in meter panel)
This lamp indicates the following items:
Valve check
Drive condition (2W D-4W D)
Operating condition (2Hz: Actuator in operation, mechanism
standby)
Restrictions on operation (4Hz, including indication of
interrupted operation due
to excessive load)

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TRANSFER CONTROL SYSTEM 7D1-7
7B4-PDF3
4L indicator (in meter panel)
This lamp indicates following items:
Valve check
Driving status (High-Low)
Operating status (2Hz: Actuator in operation, mechanism
standby)
Restrictions on operation (4Hz)






















RTW 77DSH000601
Neutral indicator (in operation switch panel)
This LED indicates following items:
LED check
Driving status (Neutral)
Operating status (2Hz: Actuator in operation, mechanism
standby)
Restrictions on operation (4Hz)
7B4-PDF5
Check 4WD warning light (in meter panel)
This light indicates following items:
Valve check
Faulty actuator limit SW , and circuit related faults with the limit
switch



RTW 77DSH000501
4WD switch
Switch to transmit a switching command to the 2H, 4H,
Neutral, or 4L position.
It comprises 3 PUSH momentary switches. By pushing the 2H
and 4L switches for 10 seconds,
operation is changed to the neutral position.
To shift from the neutral to another position, push another
switch for 10 seconds.



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7D1-12 TRANSFER CONTROL SYSTEM
Functions of Switch and indicator Lamp
Transfer-related indicator lamp and switch function

Item 4WD
lamp 4L lamp Neutral
lamp Check
4WD
warning light 4WD
switch Actu ato r
detection (limit)
switches
LS1, LS2, LS3. and LS4
1 = on
2 = off Transfer
4WD
switch Transfer
neutral switch SOF
actuator switch Or
Axl e
dummy Remarks
2H Off Off Off Off No
operation 1,0,1,0 Open Open Open -----
4H start
of
operation Off Off Off Off 4H position
for 0.1
second 1,0,1,0 Open Open Open Switch
operation sensor
Start of
operation Blinking
(2HZ) Off Off Off No
operation 1,1,1,0
0,0,1,0
0,1,1,0
0,1,1,1 Open Open Open
2H to 4H
while
driving
During
operation
(Synchro) Blinking
(2HZ) Off Off Off No
operation 1,1,1,0
0,0,1,0
0,1,1,0
0,1,1,1 Open Open Open 2H to 4H
using
synchro and
retrial
During
operation (Axle
drive) Blinking
(2HZ) Off Off Off No
operation 0,0,1,1 Closed Open Open Axle drive
Axle
waiting Blinking
(2HZ) Off Off Off No
operation 0,0,1,1 Closed Open Open Axle drive
4H On Off Off Off No
operation 0,0,1,1 Closed Open Closed -----
4L start
of
operation On Off Off Off 4L position
for 0.1
second 0,0,1,1 Closed Open Closed Switch
operation sensor
Start of
operation On Blinking
(2HZ) Off Off No
operation 0,0,0,1
0,1,0,1 Closed Open Closed 4H to 4L
while
driving
During
operation (N) Off
Blinking
(2HZ) Off Off No
operation 0,0,0,1
0,1,0,1 Closed Closed Closed 4H to 4L
through neutral
During
operation (N) Off
Blinking
(2HZ) Off Off No
operation 0,1,0,0 Closed Closed Closed 4H to 4L
through neutral
During
operation (N) Off
Blinking
(2HZ) Off Off No
operation 1,1,0,0 Closed Closed Closed 4H to 4L
through neutral
4L
waiting On Blinking
(2HZ) Off Off No
operation 1,1,0,1 Closed Closed Closed 4H to 4L
while
waiting
4L On On Off Off No
operation 1,1,0,1 Closed Open Closed -----
4H start of
operation On Off Off Off 4H position
for 0.1
second 1,1,0,1 Closed Open Closed Switch
operation sensor

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7D1-16 TRANSFER CONTROL SYSTEM
Transfer-related indicator lamp and switch function
Skip operation
Item 4WD
lamp 4L lamp Neutral
lamp Check
4WD
warning light 4WD
switch Actu ato r
detection (limit)
switches LS1,
LS2,
LS3. and LS4
1 = on
2 = off Transfer
4WD
switch Transfer
neutral switch SOF
actuator switch Or
Axl e
dummy Remarks
2H Off Off Off Off No
operation1,0,1,0 Open Open Open -----
4L start of
operation Off Off Off Off 4L
position for 0.1
second 1,0,1,0 Open Open Open
Switch
operation sensor
Start of
operation Blinking
(2HZ) Blinking
(2HZ) Off Off No
operation 1,1,1,0
0,0,1,0
0,1,1,0
0,1,1,1 Open Open Open
2H to 4H
while
driving
During
operation
(Synchro) Blinking
(2HZ) Blinking
(2HZ) Off Off No
operation 1,1,1,0
0,0,1,0
0,1,1,0
0,1,1,1 Open Open Open 2H to 4H
using
synchro
and retrial
During
operation (Passing through 4H) Off
Blinking
(2HZ) Off Off No
operation 0,0,1,1 Closed Open Open -----
During
operation (Passing through 4H) Off
Blinking
(2HZ) Off Off No
operation 0,0,1,1
0,1,0,1 Closed Open Open -----
During
operation
(N)
On Blinking
(2HZ) Off Off No
operation
0,0,1,1
0,1,0,1 Closed Open Closed -----
During
operation (N) On
Blinking
(2HZ) Off Off No
operation 0,1,0,0 Closed Open Closed Switch
operation sensor
During
operation (N) On
Blinking
(2HZ) Off Off No
operation 0,0,1,1 Closed Open Closed 4H to 4L
while
driving
During
operation (Axle
drive) Blinking
(2HZ) Blinking
(2HZ) Off Off No
operation 0,0,1,1 Closed Open Open
-----
Axle
waiting Blinking
(2HZ) Blinking
(2HZ) Off Off No
operation 0,0,1,1 Closed Open Open -----
4L waiting On Blinking
(2HZ) Off Off No
operation 1,1,0,1 Closed Closed Closed 4H to 4L
while
waiting
4L On On Off Off No
operation1,1,0,1 Closed Open Closed -----

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TRANSFER CONTROL SYSTEM 7D1-19
Transfer-related indicator lamp and switch function
2H→Neutral →2H
Item 4WD
lamp 4L lamp Neutral
lamp Check
4WD
warning light 4WD
switch Actu ato r
detection (limit)
switches LS1,
LS2,
LS3. and LS4
1 = on
2 = off Transfer
4WD
switch Transfer
neutral switch SOF
actuator switch Or
Axl e
dummy Remarks
2H Off Off Off Off No
operation1,0,1,0 Open Open Open -----
Neutral
start of
operation Off Off Off Off Neutral
position for 10
seconds 1,0,1,0 Open Open Open
Switch
operation sensor
Start of
operation Off Off Blinking
(2HZ) Off No
operation 1,1,1,0
0,0,1,0
0,1,1,0
0,1,1,1 Open Open Open
2H to 4H
while
driving
During
operation
(Synchro) Off Off
Blinking
(2HZ) Off No
operation 1,1,1,0
0,0,1,0
0,1,1,0
0,1,1,1 Open Open Open 2H to 4H
using
synchro
and retrial
During
operation (Passing through 4H) Off Off
Blinking
(2HZ) Off No
operation 0,0,1,1 Closed Open Closed -----
During
operation (Passing through 4H) Off Off
Blinking
(2HZ) Off No
operation 0,0,0,1
0,1,0,1 Closed Open Closed 4H to 4L
while
driving
During
operation
(N)
Off Off Blinking
(2HZ) Off No
operation
0,0,0,1
0,1,0,1 Closed Closed Closed
4H to 4L
through
neutral
During
operation (N) Off Off
Blinking
(2HZ) Off No
operation 0,1,0,0 Closed Closed Closed Switch
operation sensor
Neutral Off Off On Off No
operation0,1,0,0 Closed Closed Open -----
2H start of
operation Off Off On Off 2H
position for 10
seconds 0,1,0,0 Closed Open Closed
Switch
operation sensor
During
operation (Passing through N) Off
Blinking
(2HZ) Off Off No
operation 0,1,0,0 Closed Closed Closed 4L to 4H
through neutral
During
operation Off Blinking
(2HZ) Off Off No
operation 0,1,0,1
0,0,0,1 Closed Closed Closed 4L to 4H
while
driving

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7D1-46 TRANSFER CONTROL SYSTEM
Diagnosis
Before determining a trouble (Non-trouble mode)
1. When shifting from 2H to 4H:
1-1-1 When the flashing frequency of the 4WD indicator is changed from 2Hz to 4Hz (Shift on the fly) If the load is too large to shift the gears synchronously, the operation is repeated up to 3 times. If the shifting
is not effected after being repeated 3 times, the indicator frequency is changed from 2Hz to 4Hz. At the same
time, the actuator condition is changed to 2H, indicator flashes at 4Hz for 10 seconds, and then goes out.
Cause of excessive synchronous shifting load
• Extremely low temperature (the oil viscosity of the front differential increases requiring a large load for
synchronization).
• High speed (since the difference of relative revolutions of gears to be shifted synchronously is too large,
required work load per unit time becomes larger).
Step 1-1-1:
Stop the vehicle or decrease the speed and operate as required again.
1-1-2 When the flashing frequency of the 4WD indicator is changed from 2Hz to 4Hz (Rigid and free wheel
Hub) / Block out of meshing spline in transfer case.
Step 1-1-2:
Run the vehicle forward and backward several meters and operate as required again.
1-2 When the flashing of 4WD indicator at 2Hz continues more than 11.5 seconds (repetition of 3 times of
above No.1 is counted) (Shift on the fly)
If there is difference of revolutions and phases between the front wheel and the axle, connecting the front
wheel and axle is difficult.
Until shifting in the transfer and connection of the front wheel and axle are completed
∗, the indicator flashes at
a frequency of 2Hz. In the above case, the indicator continues flashing at a frequency of 2Hz until the
connection of the front axle is completed. (If the shifting in the transfer is not completed, the flashing
frequency is changed to 4Hz (above No.1).)
By correcting the difference of relative revolutions and deviation of phases, the shifting can be completed.
Step 1-2:
While the vehicle is running, check it is safe around the vehicle and then accelerate or decelerate the
vehicle while going straight.
When the vehicle is at a stop, run the vehicle forward and backward several meters.

2. When shifting from 4H to 2H
2-1 When 4WD indicator continues flashing at 2Hz
W hen shifting from 4H to 2H, the 4W D indicator continues flashing at 2Hz until separation in the transfer and
the separation of the front wheel axle are completed∗. W hen torsional torque is accumulated in the drive
system, separation in the transfer and separation of the front axle∗ is difficult. In such a case, they can be
separated by removing the torsional torque of the drive system.
Step 2-1:
While the vehicle is running, check it is safe around the vehicle and then accelerate or decelerate the
vehicle while going straight.
When the vehicle is in stop, run the vehicle several meters forward and backward.

∗: Shift on the fly only.


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TRANSFER CONTROL SYSTEM 7D1-47
3. Shifting from 4H to 4L
3-1 When the 4L indicator flashes at 2Hz
W hen shifting from 4H to 4L, the 4L indicator continues flashing at 2Hz until shifting in the transfer case is
completed. The phases of the engaged splines may sometimes deviate preventing completion of shifting. By
correcting the deviation of phases, shifting is completed.

Step 3-1:
(In case of AT): Set the select bar of the transmission to the D position.
(In case of MT): Set the lever of the transmission to a position allowing running and engage the clutch gently.
At this time, some rotating force acts on the engaged splines, phase is corrected and the engagement is
completed.
3-2 When the 4L indicator flashes at 2Hz for 10 seconds and then keeps ON again (AT vehicle)
This condition occurs when torsional torque has been generated between the transmission and road surface
and the transfer standby mechanism cannot absorb it completely.

Step 3-2:
Set the select lever of the transmission to the N position. (Stepping on the brake pedal is effective at
this time.)
3-3 When the 4L indicator flashes at a frequency of 4Hz
Shifting from 4H to 4L is restricted.
W hen the vehicle is running, the transmission lever is at the running range and the engine speed is high (L4:
3000rpm or more V6: 2000rpm), the transfer cannot be shifted from 4H to 4L (restriction on operation).
Restriction on operation (Except 4JA1-T)
The 4H, neutral and 4L shifting mechanism has no synchronization function. Therefore, if relative rotations in the
mechanism become excessive, shifting exerts adverse influence on the internal mechanism of the transfer. To
avoid such a trouble, vehicle condition is detected to restrict the operation (vehicle speed, engine speed and TM
position).
Requirement to restrict the speed: Vehicle should be in stop. Due to the detection logic, time to wait for start of operation may be required.
A/T: If the vehicle is in stop for a long time at the TM running range (D, 1, 2) before operating the AT, waiting
time becomes longer (from 1 second to 3 minutes at the maximum).
M/T: If the vehicle is at stop with the clutch stepped on at the T/M running position (1 – R), the time to wait
becomes longer.
W aiting time means the time commencing from when other requirements (engine speed and T/M position) are
met to permission of the speed restriction. Operation during the waiting time is not permissible.
The waiting time is 1 second at the minimum and increases up to 5 seconds if the above condition continues for
3 minutes. After that, the waiting time increases up to 3 minutes in 2 minute intervals.
W hen it is clear that the above condition has continued and reduction of waiting time is required, turn on or off
the ignition or start and stop the vehicle several meters.
Requirements for permission of restriction on engine speed: Engine speed should be decreased.
The engine speed of 3000rpm (V6: 2000rpm) or below is advisable.
Requirements for permission of restriction on T/M position restriction:
(AT) N range is recommended
(MT) should be at the neutral.

These requirements for permission should all be met before the switch is operated. If the requirements are met
after operation, operation is not automatically effected but re-operation is required after permission is given.

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7D1-48 TRANSFER CONTROL SYSTEM
Restriction on operation (4JA1-T)
The 4H, neutral and 4L shifting mechanism has no synchronization function. Therefore, if relative rotations in the
mechanism become excessive, shifting exerts adverse influence on the internal mechanism of the transfer. To
avoid such a trouble, vehicle condition is detected to restrict the operation (vehicle speed, and TM position).
Requirement to restrict the speed: Vehicle should be in stop.
Requirements for permission of restriction on engine speed: Engine speed should be decreased.
The engine speed of 3000rpm or below is advisable.
Requirements for permission of restriction on T/M position restriction:
should be at the neutral.

These requirements for permission should be all met before the switch is operated. If the requirements are met
after operation, operation is not automatically effected but re-operation is required after permission is given.
Note: Don’t’ accelerate engine speed a the time of this operation.

Step 3-3:
Stop the vehicle. (Close the accelerator and decrease the engine speed to below L4: 3000rpm, V6: 2000rpm.)
(In case of AT): Set the transmission select lever to the N position.
(In case of MT): Set the transmission lever to the neutral position. (Stepping on the clutch is recommended.) Push the 4L button.
If shifting operation is not completed (the lamp flashes at 2Hz), perform step 3-1.

4. Shifting from 4L to 4H
4-1 When 4L indicator continues flashing at 2Hz
W hen shifting from 4L to 4H, the 4L indicator continues flashing at 2Hz until the shifting in the transfer case is
completed. Phases of engaged splines may deviate and the operation may not be completed in some cases.
Shifting is completed by correcting the deviation of the splines.

Step 4-1: (same as step 3-1)
(In case of AT): Set the transmission select lever to the D position.
(In case of MT): Shift the transmission lever to a position allowing running and engage the clutch gently.

4-2 When the indicator continues flashing at 2Hz for 10 seconds and then keeps on at 4L again (AT
vehicle)
This condition occurs when torsional torque has been generated between the transmission and the road
surface (use of the parking position on a slope). Resistance against the separation of the driving force cannot
be completed by the waiting mechanism of the transfer.
Shifting is also possible by using the brake at the neutral position of the transmission

Step 4-2: (Same procedure as the step 3-2)
Set the transmission select lever to the N position.
(Leaving the brake lever and stepping on it again is recommended.)

4-3 When the 4L indicator flashes at 4Hz
Shifting from 4L to 4H is restricted.
W hen the vehicle is running, the transmission lever is at the running range, and the engine speed is high, the
transfer 4L cannot be shifted to 4H.


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TRANSFER CONTROL SYSTEM 7D1-49
Step 4-3: (Same procedure as the step 3-3)
Stop the vehicle (close the accelerator and decrease the engine speed to L4: 3000rpm V6: 2000rpm or below).
(In case of AT): Set the transmission select lever to the N position.
(In case of MT): Set the transmission lever to the neutral position (stepping on the clutch lever is recommended).
Push the 4H button.
If shifting is not complete (indicator flashes at 2Hz), go to step 4-1.

5. When shifting from 4H or 4L to neutral
(Same procedure is required when shifting from 2H but in such a case, requirements for shifting from
2H to 4H are also applied.)
5-1 Neutral indicator continues flashing at 2Hz The neutral indicator continues flashing at 2Hz until 4H (4L) is completely separated in the transfer. If torsional
torque has accumulated between the transmission and road surface, separation may be difficult.
Step 5-1:
If the operation is not complete, execute step 7 for confirmation.
(In case of AT): Set the transmission select lever to the D position. After confirming that the gears are at the neutral position, return the lever to the N
position.
(In case of MT): Set the transmission lever to a vehicle running position and engage the clutch gently. After confirming that the gears are at the neutral position, return the lever to the
neutral position
5-2 When the neutral indicator flashes at 4Hz
As in the case of shifting from 4L to 4H, restriction is imposed to the operation from 4L or 4H (including 2H). If
the transmission lever is at a running range and engine speed is high (L4: 3000rpm, V6: 2000rpm or more)
while the vehicle is running, operation from the 4L or 4H (including 2H) of the transfer to the neutral is
impossible (restriction on operation).
Step 5-2:
Stop the vehicle.
(In case of AT): Set the transmission select lever to the N (or P) position.
(In case of MT): Set the transmission lever to the neutral position (at this time, stepping on the clutch is recommended).
Keep pushing the 2H and 4L button for 10 seconds.
Follow the start procedure for confirmation. (Confirmation of drive force is not transferred; same as in
step 5-1)
After the confirmation, set the transmission to the neutral position in the case of MT or to the neutral
position in the case of AT.

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