2002 ISUZU AXIOM turn signal

4B1±2
DRIVELINE CONTROL SYSTEM
Shift On The Fly System
Outline of Shift on The Fly System
The shift on the fly system switches between 2 wheel
drive (2WD) and 4 wheel drive (4WD) electronically by the
driver turning the TOD switch on the instrument panel.
This system will control the following operations. (Shifting
between ª4Hº and ª4Lº must be performed by TOD
switch.)
1. Transmitting the torque to the front propeller shaft.
2. Connecting front wheels to, and disconnecting them
from, the front axles by axle motor actuator.
3. Indicating on instrument panel.
4. 4WD out signal to other Electronic Brake Control
Module (EBCM).
System Diagrams
412R200008

4B1±4
DRIVELINE CONTROL SYSTEM
Functions of Indicator Lamp
TOD Switch and Indication of Drive Mode
The TOD switch sends signals to the TOD control unit
which selects drive modes and controls the shift on the fly
system (axle disconnect : ADC).
TOD
switch
tt
Drive modeTransfer shift conditionTransfer posi-
tion detectionShift on the flyTOD indicator
state
state4HSW4LSWAxle
SWADC circuit
2HRear-wheel
drive (RWD)Permissible during
driving (less than
100 km/h or 62 mph)OFFOFFOFFTurning on
electricity
TODElectronic
torque split
4WD (HIGH)
OFFOFFONTurning off
electricity
4WD (HIGH)
(TOD)AT: Neutral
Brake: Applied
Th t (l4LLow range
mechanical
direct 4WD
(LOW) (4L)The car stops (less
than 2 km/h or
1.2 mph and less than
1500 rpm)OFFONONTurning off
electricity
ADC: Shift on the fly
SW: Switch
Bulb check :The bulb of indicator lamp is checked for 2
seconds when ignition key is turned on.
Bulb Check
When the starter switch is turned on, the TOD indicator
lamps comes on as shown below.
NOTE: Once the starter switch is turned on, all the TOD
indicator lamps are lit for two seconds even if the transfer
lever is in any position.
C07RW016

4B2±3
DRIVE LINE CONTROL SYSTEM (TOD)
TOD Control
The TOD position usually drives the rear wheels, and
transmits the torque to the front wheels with the help of
electronically controlled torque split mechanism
according to running conditions encountered. The driving
force is directly transmitted to the rear wheels. This force
is split by the transfer and delivered to the front wheels.
The magnitude of the torque transmitted to the front
wheels is controlled by changing the pressing force of the
multi plate disk clutch built in the transfer unit. The
pressing force of the clutch is controlled by changing the
duty ratio to the electromagnetic coil mounted to the rear
of the clutch. When the clutch is completely disengaged,
the rear wheels are driven. When the clutch is completely
engaged, a rigid four wheel drive mode is obtained. The
torque split status is controlled continuously between the
rear wheel and four wheel drive modes. This system
includes front and rear speed sensors, and receives
throttle position sensor and engine speed information
from the PCM, ABS control unit signal, brake switch
signal, and shift motor position information.
The control unit receives signals sent from these sensors
and changes the pressing force of the multi-plate disk
clutch to determine the torque distribution on the front and
rear wheels. Therefore, when the slip of the rear wheels is
increased against the current torque level in the normal
rear wheel drive mode, the control unit detects the slip
condition, determines the optimum torque based on the
feedback control logic, and increases the torque to the
front wheels.
The control unit uses the signal from the throttle position
sensor to predict the future vehicle condition and the
intention of the driver with respect to acceleration and
deceleration, and determines the initial torque distribution
using these data and the information from the speed
sensors.
In case of small circle turning in the parking lot, for
example, the control unit minimizes the clutch pressing
force to restrict a braking phenomenon. When the ABS
becomes active, the control unit optimizes the clutch
pressing force to ensure stable braking.
TOD Indicator Control
The TOD indicator on the instrument panel informs the
driver of the current working status of the transfer unit.
The information is the drive mode (2H, TOD, 4L,
transition). The indicator can display occasional errors
and corresponding error codes.
Abbreviations
ABS Anti-lock Brake System
ADC Axle Disconnect
(Shift on the fly system)
VB Battery Voltage
VIGN Ignition Voltage

4B2±9
DRIVE LINE CONTROL SYSTEM (TOD)
High-Low Shift Motor
F07R200002
Legend
(1) Reduction Hub
(2) Mechanical Lock Sleeve (Including the built-in
Spring)
(3) Lockup Shift Fork
(4) Return Spring
(5) To TOD Control Unit
(6) Fixed Contact Point
(7) Encoder
(8) Worm gear
(9) Rotate
(10) Shift Motor
(11) The shift cam (12) can be turned freely around
the shift shaft (14).(12) Shift Cam
(13) Torsional Spring
(14) Shift Shaft
(15) Shift Rod
(16) High-Low Shift Fork
(17) High
(18) Low
(19) 2H and TOD Position
(20) Direct Four Wheel Drive (4L Position)
(21) Earth
(22) High
(23) Low
(24) High
(25) Low
When the TOD switch is changed to the 4L (or TOD)
position from the TOD (or 4L) position, the TOD control
unit drives the high±low shift motor according to the
signal. The transfer is shifted to low range from high range
(or to high range from low range) by the shift motor.
The high-low shift motor can run, only when the operation
meets the following conditions to prevent an unexpected
shift between high and low range by a operation error.
1. The car stops. (less than 2 km/h or 1.2 mph and less
than 1500 rpm.)2. The AT selector position is neutral.
3. The brake is applied. (brake switch is on.)
The shift motor has a built-in encoder which watches
motor rotation position. The control unit controls the
rotation of the shift motor based on the position code
detected by the encoder.
The encoder position plate turns together with the shift
shaft and switches on or off the current from the 4 (four)
fixed contact points on the case, then the control unit
recognizes the rotation position of the shift motor.

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±10
Motor Position and Encoder Position Code
High-Low Shift Motor PositionHigh-Low shift Motor Encoder SignalState of
MotorPosition aPosition bPosition cPosition dMotor
High EndAOFFOFFOFFONHigh Position
Near High EndBOFFONOFFON
High PositionCONONOFFON
Middle Zone (1)DONONONON
Middle Zone (2)EOFFONONON
Neutral PositionFOFFONONOFF
Middle Zone (3)GONONONOFF
Low PositionHONOFFONOFFLow Position
Low EndIONOFFONON
Encode Position Plate
F04R100005
Legend
(1) OFF Aria
(2) ON Aria(3) Low
(4) High
(5) Earth
Shift High Range and Low Range
When the car is stops (less than 2km/h or 1.2 mph and
less than 1500 rpm), the AT selector position is neutral,
the brake is applied, and the TOD switch is changed to 4L
from TOD (or to TOD from 4L), the high-low shift motor
starts by power applied from the TOD control unit and
turns the shift shaft through the worm gear.
The shift shaft turns the shift cam through the torsional
spring.
The end of the shift cam moves the lockup shift fork and
the spiral groove on the outside of the shift cam slides the
high±low shift fork.

4B2±11
DRIVE LINE CONTROL SYSTEM (TOD)
Functions of TOD Switch and
Indicator Lamp
TOD Switch and Indication of Drive Mode
The TOD switch sends signals to the TOD control unit
which selects drive modes and controls the shift on the fly
system (axle disconnect : ADC).
TOD
switch
state
Drive modeTransfer shift conditionTransfer
position
detectionShift on the flyTOD indicator
state
4HSW4LSWAxle
SWADC circuit
2HRear-wheel
drive (RWD)Permissible during
driving (less than
100 km/h or 62 mph)OFFOFFOFFTurning on
electricity
TODElectronic
torque split
4WD (TOD)OFFOFFONTurning off
electricity
AT: Neutral
Brake: Applied
The car stops4LLow range
mechanical
direct 4WD
(4L)The car sto s
(less than 2 km/h or
1.2 mph and less than
1500 rpm)OFFONONTurning off
electricity
ADC: Shift on the fly
SW: Switch
TOD
Switch
TOD control unit terminal No.TOD indicator
stateSwitch
stateTOD indicatorTOD switchstate
state
7(Front)8(Rear)19(Auto)30(2H)43(4L)
2HOFFONOFFONOFF
TODONONONOFFOFF
4LONONOFFOFFON

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±12
Indication During Transition of Shift Rod
When the TOD switch is turned, and the signals from the
AXLE switch do not comply with the signal conditions of
the 4H and 4L switch, the indicator lamp state selected on
the TOD switch and light-off mode are repeatedly output
at an interval of 1.0 second.NOTE: After the TOD switch is turned to the specified
position and the AXLE switch generates compliant
signals, the normal output status is returned.
C07R100010
Bulb Check
When the starter switch is turned on, the TOD indicator
lamps go on as shown below.NOTE: Once the starter switch is turned on, all the TOD
indicator lamps are lit for two seconds even if the TOD
switch is in any position.
C07RW016

4B2±13
DRIVE LINE CONTROL SYSTEM (TOD)
Simplified checking method of ABS IN and BRAKE ON signals:
In the event that any of the signal inputs listed below are
observed while the self-diagnostic code is being
displayed (the self-diagnostic connector is short-circuited
to GND), you can simply check the ABS IN and BRAKE
ON signals as shown in the figures below.
C07R200002
Check Lamp
Check Lamp Bulb Check
When the starter switch is turned on in the normal state,
the control unit turns on the CHECK lamp to check the
bulb.
C07RW019