2004 ISUZU TF SERIES 4WD

7D1-6 TRANSFER CONTROL SYSTEM
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 in sometime.
This mechanism is provided to protect the shift mechanism
from the force to prevent the movement of the sleeve
(torsional torque etc. of the drive system). By releasing the
preventive force, the sleeve can move to 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, that is,
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. For this
reason, the rod position and the actual sleeve position may be
offset in some cases.
This system is provided to protect the shift mechanism from
the 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 is provided to the actuator at 4 positions, which
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 (2WD-4WD)
Operating condition (2Hz: Actuator in operation, mechanism
standby)
Restrictions on operation (4Hz, including indication of
interrupted operation due
to excessive load)
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)

TRANSFER CONTROL SYSTEM 7D1-7
7B4-PDF3
7B4-PDF4
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 fault of circuit related with the
limit switch
825R300018
4WD switch
Switch to transmit a switching command to the 2H, 4H,
Neutral, or 4L position.
It comprises 3 PUSH momentary switches. By keeping to push
the 2H and 4L switches for 10 seconds,
operation is instructed to the neutral position.
To shift from the neutral to other position, other required
switches should be pushed for 10 seconds.

TRANSFER CONTROL SYSTEM 7D1-11
Function of Switch and indicator Lamp
Transfer-related indicator lamp and switch function

Item 4WD
lamp 4L lampNeutral
lamp Check
4WD
warning
light 4WD
switch Actuator
detection
(limit)
switches
LS1, LS2,
LS3. and
LS4
1 = on
2 = off Transfer
4WD
switch Transfer
neutral
switch SOF
actuator
switch
Or
Axle
dummyRemarks
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

7D1-12 TRANSFER CONTROL SYSTEM
Item 4WD
lamp 4L lampNeutral
lamp Check
4WD
warning
light 4WD
switch Actuator
detection
(limit)
switches
LS1, LS2,
LS3. and
LS4
1 = on
2 = off Transfer
4WD
switch Transfer
neutral
switch SOF
actuator
switch
Or
Axle
dummyRemarks
During
operation On Blinking
(2HZ) Off Off No
operation 1,1,0,1 Closed Open Closed 4L to 4H
while
driving
During
operation
(N) Off Blinking
(2HZ) Off Off No
operation 1,1,0,0 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
4H
waiting Off Blinking
(2HZ) Off Off No
operation 0,0,1,1 Closed Closed Closed
4L to 4H
while
waiting
4H On Off Off Off No
operation 0,0,1,1 Closed Open Closed -----
2H start
of
operation On Off Off Off 2H position
for 0.1
second 0,0,1,1 Closed Open Closed Switch
operation
sensor
Start of
operation Blinking
(2HZ) Off Off Off No
operation 0,1,1,1
0,1,1,0
0,0,1,0
1,1,1,0 Closed Open Closed 2H to 4H
while
driving
During
operation
(Axle) Blinking
(2HZ) Off Off Off No
operation 0,1,1,1
0,1,1,0
0,0,1,0
1,1,1,0 Open Open Closed Axle drive
Axle
waiting
Blinking
(2HZ) Off Off Off No
operation 1,0,1,0 Open Open Closed Axle
waiting
2H Off Off Off Off No
operation 1,0,1,0 Open Open Open -----

TRANSFER CONTROL SYSTEM 7D1-13
2H to 4H retrial

Item 4WD
lamp 4L lampNeutral
lamp Check
4WD
warning
light 4WD
switch Actuator
detection
(limit)
switches
LS1, LS2,
LS3. and
LS4
1 = on
2 = off Transfer
4WD
switch Transfer
neutral
switch SOF
actuator
switch
Or
Axle
dummyRemarks
2H Off Off Off Off No
operation1,0,1,0 Open Open Open -----
4H start
of
operation Off Off Off Off 4H
position
for 0.1
second 1,0,1,0 Open Open Open -----
Start of
operation Blinking
(2HZ) Off Off Off No
operation1,1,1,0
0,0,1,0
0,1,1,0
0,1,1,1 Open Open Open 2H to 4H
while
driving
During
operation
(Synchro)
(Go to 4H
if synchro
complete) Blinking
(2HZ) Off Off Off No
operation1,1,1,0
0,0,1,0
0,1,1,0
0,1,1,1 Open Open Open 2H to 4H
using
synchro
and retrial
X 2
Abandon
ed
operation
(2H) Blinking
(4HZ) Off Off Off No
operation1,0,1,0 Open Open Open Return to
2H
2H
indication
after
10second
s
Off Off Off Off No
operation1,0,1,0 Open Open Open -----

 Completion of transfer case H-L area and axle shift timing may cause some variation in 2Hz blinking pattern.

7D1-14 TRANSFER CONTROL SYSTEM
Operational limits (4H




4L) (Vehicle speed, engine speed, and transmission position not specified)

Item 4WD
lamp 4L lampNeutral
lamp Check
4WD
warning
light 4WD
switch Actuator
detection
(limit)
switches
LS1, LS2,
LS3. and
LS4
1 = on
2 = off Transfer
4WD
switch Transfer
neutral
switch SOF
actuator
switch
Or
Axle
dummyRemarks
4H On Off Off Off Open 0,0,1,1 Closed Open Closed -----
4H start
of
operation On Off Off Off 4L
position
for 0.1
second 0,0,1,1 Closed Open Closed -----
10
second
display
during
limitation On Blinking
(4HZ) Off Off Open 0,0,1,1 Closed Open Closed No
operation
during
limitation
Go to 4H
after 10
seconds
On Off Off Off Open 0,0,1,1 Closed Open Closed -----

Operational limits (4L





4H) (Vehicle speed, engine speed, and transmission position not specified)

Item 4WD
lamp 4L lampNeutral
lamp Check
4WD
warning
light 4WD
switch Actuator
detection
(limit)
switches
LS1, LS2,
LS3. and
LS4
1 = on
2 = off Transfer
4WD
switch Transfer
neutral
switch SOF
actuator
switch
Or
Axle
dummyRemarks
4L On On Off Off No
operation1,1,0,1 Closed Open Closed -----
4L start of
operation On On Off Off 4H
position
for 0.1
second 1,1,0,1 Closed Open Closed -----
10
second
display
during
limitation On Blinking
(4HZ) Off Off Open 1,1,0,1 Closed Open Closed No
operation
during
limitation
Go to 4L
after 10
seconds
On On Off Off No
operation1,1,0,1 Closed Open Closed -----


Under some conditions, a secondary operational indication may be received when the 4Hz operational indication
is present.

TRANSFER CONTROL SYSTEM 7D1-15
Transfer-related indicator lamp and switch function
Skip operation
Item 4WD
lamp 4L lampNeutral
lamp Check
4WD
warning
light 4WD
switch Actuator
detectio
n (limit)
switches
LS1,
LS2,
LS3. and
LS4
1 = on
2 = off Transfer
4WD
switch Transfer
neutral
switch SOF
actuator
switch
Or
Axle
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
operation1,1,1,0
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
operation1,1,1,0
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
operation0,0,1,1 Closed Open Open -----
During
operation
(Passing
through
4H) Off Blinking
(2HZ) Off Off No
operation0,0,1,1
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
operation0,1,0,0 Closed Open Closed Switch
operation
sensor
During
operation
(N) On Blinking
(2HZ) Off Off No
operation0,0,1,1 Closed Open Closed 4H to 4L
while
driving
During
operation
(Axle
drive) Blinking
(2HZ) Blinking
(2HZ) Off Off No
operation0,0,1,1 Closed Open Open -----
Axle
waiting Blinking
(2HZ) Blinking
(2HZ) Off Off No
operation0,0,1,1 Closed Open Open -----
4L waiting On Blinking
(2HZ) Off Off No
operation1,1,0,1 Closed Closed Closed 4H to 4L
while
waiting
4L On On Off Off No
operation1,1,0,1 Closed Open Closed -----

7D1-16 TRANSFER CONTROL SYSTEM
Item 4WD
lamp 4L lampNeutral
lamp Check
4WD
lamp 4WD
switch Actuator
detectio
n (limit)
switches
LS1,
LS2,
LS3. and
LS4
1 = on
2 = off Transfer
4WD
switch Transfer
neutral
switch SOF
actuator
switch
Or
Axle
dummy Remarks
2H start of
operation On On Off Off 2H
position
for 0.1
second 1,1,0,1 Closed Open Closed Switch
operation
sensor
During
operation Blinking
(2HZ) Blinking
(2HZ) Off Off No
operation1,1,0,1 Closed Open Closed 4L to 4H
while
driving
During
operation
(Passing
through
N) On Blinking
(2HZ) Off Off No
operation1,1,0,0 Closed Closed Closed 4L to 4H
through
neutral
During
operation
(Passing
through
N) Off Blinking
(2HZ) Off Off No
operation0,1,0,0 Closed Closed Closed 4L to 4H
through
neutral
During
operation
(4H
waiting) Off Blinking
(2HZ) Off Off No
operation0,0,1,1 Closed Closed Closed 4L to 4H
while
waiting
During
operation
(Axle) Off while
waiting for
start of H
shift Blinking
(2HZ)
while
waiting for
start of H
shift Off Off No
operation0,1,1,1
0,1,1,0
0,0,1,0
1,1,1,0 Closed Open Closed 2H to 4H
while
driving
During
operation
(Axle) Blinking
(2HZ) at
end of H
shift Off at end
of H shiftOff Off No
operation0,1,1,1
0,1,1,0
0,0,1,0
1,1,1,0 Closed Open Closed Axle
driving
Axle
waiting
Blinking
(2HZ) Off Off Off No
operation1,0,1,0 Open Open Closed -----
2H Off Off Off Off No
operation1,0,1,0 Open Open Open -----


Completion of transfer case H-L area and axle shift timing may cause some variation in 2Hz blinking pattern.