Isuzu KB P190. Manual — part 1234

7D1-62 TRANSFER CONTROL SYSTEM

From 4L to 4H: After the correction step 4-3(*), 4Lo indicator blinks at 4H.

Step Action

Yes

Is the ignition switch ON?

Turn it OFF once.

Go to step 2.

Turn ON the ignition switch and
check the valve. Do not start
the engine.
Has the valve check for 2
seconds been completed
normally?

Go to step 3.

Refer to the paragraph about the
indicator when it does not react
when shifted from 2H to 4H.
After taking the remedy, trace this
chart from the beginning.

Can be shifted to 2H and then to
4L?

Go to step 4.
(Impossible usually.)
Failed controller

In case of Check 4WD, shifting to
2H is possible.
Returning to 4L is impossible.
Refer to the paragraph about
Check4WD.

Set to N position in case of AT
and set to the neutral position in
case of MT and check if the
lamp blinks at 4Hz after
operation.

Failed T/M position switch and
harness (failure of TM1 and TM2
harness and their related
switches shown in the figure).
Incorrect wiring.
Repair as required and trace this
chart from the beginning.

Press the operation switch of 4L
and go to step 5.

Start the engine and use the
vehicle.
Does the speedometer run at
this time?

Go to step 6.

Failure of speed sensor or
disconnection or short of harness
(for the meter).
After repairing, trace this chart
from the beginning.

Check the harness between the
transfer controller and speed
sensor.
(Check the engine rotation
detection harness at the same
time.)
Is any trouble detected?

Failed harness between the
transfer controller and speed
sensor.
After repairing, trace this chart
from the beginning.
(Repair the engine rotation
detection unit, if required.)

Go to step 7.

Run the vehicle for several
meters, stop it, meet the
permission requirements for
operation limits.
Did you wait for several seconds
after the requirements were
met?

Failed transfer controller.
Replace the controller and trace
this chart from the beginning.

You did not wait for enough time.
Optimum waiting time is 1 second
or maximum 3 minutes,
depending on the previous
conditions.
Refer to the paragraph about
operation without failure.

*Before determining a trouble (Non-trouble mode)

TRANSFER CONTROL SYSTEM 7D1-63

To neutral: After the correction step 5-2(*), neutral indicator blinks at 4Hz.
Check the function between H and L according to the chart for 4L to 4H instead of check
for the requirements of neutral.

Step Action

Yes

Is the ignition switch ON?

Turn it OFF once.

Go to step 2.

Turn ON the ignition switch and
check the valve. Do not start the
engine.
Has the valve check for 2
seconds been completed
normally?

Go to step 3.

Refer to the paragraph about the
indicator when it does not react
when shifted from 2H to 4H (7D1-
37).
After taking the remedy, trace this
chart from the beginning.

Can be shifted to 2H and then to
4L?

Go to step 4.
(Impossible usually.)
Failed controller

Refer to the paragraph about
shifting from 2H to 4H.
In particular, check if not at the
Check4WD condition, return to
this chart and trace it from the
beginning.
In case of Check4WD, shifting to
2H is possible.
Returning to 4H is impossible.
Refer to the paragraph about
Check4WD.

Set to N position in case of AT
and set to the neutral position in
case of MT and check if the lamp
blinks at 4Hz after operation.

Failed T/M position switch and
harness (failure of TM1 and TM2
harness and their related
switches shown in the figure).
Incorrect wiring.
Repair as required and trace this
chart from the beginning.

Shift back to 4H and go to step 5.

Start the engine and use the
vehicle.
Does the speedometer run at this
time?

Go to step 6.

Failure of speed sensor or
disconnection or short of harness
(for the meter).
After repairing, trace this chart
from the beginning.

Check the harness between the
transfer controller and speed
sensor.
(Check the engine rotation
detection harness at the same
time.)
Is any trouble noticed?

Failed harness between the
transfer controller and speed
sensor.
After repairing, trace this chart
from the beginning.
(Repair the engine rotation
detection unit, if required.)

Go to step 7.

Run the vehicle for several
meters, stop it, meet the
permission requirements for
operation limits.
Did you wait for several seconds
after the requirements were met?

Failed controller.
Replace the controller and trace
this chart from the beginning.

You did not wait for enough time.
Optimum waiting time is 1 second
or maximum 3 minutes,
depending on the previous
conditions.
Refer to the paragraph about
operation without failure.

*Before determining a trouble (Non-trouble mode)

For shifting to neutral, 2H and 4L switches should be pressed at the same time for 10 seconds.
For shifting from neutral to other position, 2H, 4H or 4L switch should be pressed for 10 seconds.
When shifting from neutral to other position, the lamp blinking at 2Hz indicates active condition.
When the lamp keeps blinking at 2Hz, follow the step for the case when the lamp keeps blinking at 2Hz when
shifting between positions.