ISUZU TROOPER 1998 Service Repair Manual

4B1±8
DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)
Normal Operation
The motor actuator mounted on transfer rear case is
driven by signal from 4WD switch on instrument panel.
After complete the connecting transfer front output gear
to, or disconnecting it from, front propeller shaft, conditionof the transfer position switch changes. The vacuum
solenoid valve (VSV) is driven by the signal from transfer
position switch and the vacuum actuator connects front
wheels to, or disconnect them from, front axles.
Time Chart of Shifting Under Normal Condition
F04RW002

4B1±9 DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)
Retrial
The motor actuator starts transfer gear shifting after
signal from 4WD switch on instrument panel has been
received. But the shifting may be impossible in cold
weather or under high speed condition. When 2 seconds
have passed since transfer gear shifting started and the
transfer position switch dose not turn on (the gear
engagement is not completed), the motor reverses its
rotation for 1.2 seconds and tries again to shift transfergear. This procedure is repeated 3 times in maximum.
While this procedure, 4WD indicator lamp blinks by 2 Hz.
If the transfer position switch does not turn on after
aforementioned procedure has been repeated 3 times,
the gear shifting is stopped and 4WD indicator lamp's
blinking changes from 2Hz to 4Hz to notify driver that the
gear shifting is stopped. This blinking of indicator lamp
continues until 4WD switch is returned from 4WD to 2WD.
Time Chart of Shifting Under Severe Condition (re-
trial)
F04RW003

4B1±10
DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)
Warning at ª4Lº position :In view of the shifting
mechanism of transfer, the gear shifting from 4WD to
2WD at ª4Lº condition is impossible. Therefore, the
transfer position switch can not be turned off by 4WDswitch when vehicle is in ª4Lº condition. In the case this
condition continues for 2 seconds, the shifting to 2WD is
stopped and the indicator lamp's blinking changes from
2Hz to 4Hz to notify driver of wrong operation.
Time Chart of Shifting from 4WD to 2WD at ª4Lº
Condition
F04RW005
4WD out signal to other Electronic Hydraulic Control
Unit : 4WDcontrol unit sends 4WD out signal to other
Electronic Hydraulic Control Unit as below.
4WD out signal
(Period)
Vehicle ConditionTransfer position switchFront axle switch
120 ms2WD2WD (Open)2WD (Open)
240 ms4WD4WD (Close)4WD (Close)

4B1±11 DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)
Functions of Indicator Lamp
Indication of vehicle condition : Indicator lamp is
controlled by 4WD control unit and shows vehicle
conditions as below.
Indicator
Vehicle condition4WD switchTransfer position
switchFront axle switch
Off2WDOff (Close)2WD (Open)2WD (Open)
On4WDOn (Open)4WD (Close)4WD (Close)
Blink (2Hz)OperatingOn (Open)4WD (Close)2WD (Open)
Off (Close)2WD (Open)4WD (Close)
Blink (4Hz)Stop operatingOn (Open)2WD (Open)2WD (Open)
Off (Close)4WD (Close)4WD (Close)
Bulb check :To check the bulb of indicator lamp, the
indicator lamp comes on when ignition key is turned on,
and goes off when the engine is started.
Retrials from 2WD to 4WD :In cold weather or under
high speed condition, the gear shifting (engagement)sometimes does not complete by 3 trials. In such case,
the indicator lamp inform driver of this incident as
aforementioned chart (shown at Retrial in Outline of shift
on the fly system).
Diagnosis
Before Judging That Troubles Occur
(Unfaulty mode)
When Switching from 2WD to 4WD
1.In case that blinking frequency of the 4WD
indicator changes from 2Hz to 4Hz.
When heavy synchronization load is needed, the
motor actuator tries the shifting transfer gear three
times including the activation shifting. While the
motor actuator tries shifting, the indicator blinks by
2Hz. If the third shifting fails, the indicator's blinking
changes from 2Hz to 4Hz at the same time that the
motor actuator shifted back to 2WD.
Heavy synchronization load occurs by:

extremely lower temperature.

higher speed, rotation difference of wheels during
cornering.
Solution 1: Operate again after stop the vehicle or
slow down.
2.In case that the 4WD indicator continues blinking
by 2Hz for more than 11.5 seconds.
When there is rotation difference of wheels or there
is phase difference between front wheels and axles,
it is difficult to connect front wheels to front axles. The
blinking by 2Hz shows that shifting the transfer gear
or connecting the front wheels is in the middle of
operating. In above case, the indicator's blinking by
2Hz shows that connecting the front wheels is not
completed (because the indicator's blinking changes
to 4Hz when the shifting transfer gear is impossible.).
And removal of rotation or phase difference make
connecting the front wheels possible.
Solution 2: When vehicle is running, drive
straight ahead while accelerating and
decelerating. When vehicle is at a stop, move the
vehicle forward and backward from 2 to 3 meters.When switching from 4WD to 2WD
1.In case that the 4WD indicator continues blinking
by 2Hz .
The 4WD indicator continues blinking by 2Hz until
both shifting the transfer gear and disconnecting the
front wheels are completed when switching 4WD to
2WD. When driveline is loaded with torsional torque,
the shifting transfer gear and disconnecting front
wheels are impossible. In this case, removal of
torsional torque on driveline make the shifting
transfer gear and disconnecting front wheels
possible.
Solution 3: When vehicle is running, drive
straight ahead while accelerating and
decelerating. When vehicle is at a stop, move the
vehicle forward and backward from 2 to 3 meters.
2.In case that the 4WD indicator's blinking changes
from 2Hz to 4Hz.
Check the position of transfer lever. Is it at ª4Lº
position? In view of the shifting mechanism of
transfer, the gear shifting from 4WD to 2WD at ª4Lº
condition is impossible.
Solution 4: Push the 4WD switch to 4WD, shift the
transfer lever to ªHighº position and re±operate
the 4WD switch to 2WD.

4B1±12
DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)
Parts Location (LHD / Diesel Engine Model)
D08RW852
Legend
(1) I±12
(2) I±9
(3) H±7, H±8, H±24, H±25
(4) Fuse Box
(5) C±16
(6) C±94
(7) H±4, H±5(8) P±17
(9) P±18
(10) P±19
(11) H±60
(12) Relay & Fuse Box
(13) H±12, H±16
(14) E±21
(15) E±45

4B1±13 DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)
Parts Location (LHD / Gasoline Engine Model)
D08RW854
Legend
(1) I±12
(2) I±9
(3) H±7, H±8, H±24, H±25
(4) Fuse Box
(5) C±16
(6) C±94
(7) H±5
(8) M±11, M±12(9) M±22
(10) M±23
(11) M±24
(12) H±10
(13) M±26
(14) Relay & Fuse Box
(15) H±12, H±16
(16) E±30

4B1±14
DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)
Parts Location (RHD / Diesel Engine Model)
D08RW831
Legend
(1) I±9
(2) I±12
(3) E±45
(4) E±21
(5) H±7, H±9
(6) C±16
(7) C±94(8) H±4, H±5
(9) P±17
(10) P±18
(11) P±19
(12) H±60
(13) Relay & Fuse Box
(14) H±15, H±16, H±25, H±26, H±27
(15) Fuse Box

4B1±15 DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)
Parts Location (RHD / Gasoline Engine Model)
D08RW853
Legend
(1) I±9
(2) I±12
(3) H±7, H±9
(4) C±16
(5) H±5
(6) C±94
(7) M±26
(8) M±11, M±12(9) M±22
(10) M±23
(11) M±24
(12) H±10
(13) H±12
(14) Relay & Fuse Box
(15) E±30
(16) H±15, H±16, H±25, H±26, H±27
(17) Fuse Box

4B1±16
DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)
Wiring Diagram (LHD Model)
D08RW845

4B1±17 DRIVE LINE CONTROL SYSTEM (SHIFT ON THE FLY)
Wiring Diagram (LHD / Diesel Engine Model)
D08RW841