2002 ISUZU AXIOM Service Repair Manual

4B1±5
DRIVELINE CONTROL SYSTEM
Shift On The Fly Electrical Equipment
Axle Shaft Connection and Disconnection
412R200006
Actuator Assembly
412RY00004
Axle Disconnect Controller
828RY00009

4B1±6
DRIVELINE CONTROL SYSTEM
828RY00010
Legend
(1) Output Signal
(2) Output Signal
(3) 12V
(4) Input Signal
(5) GND
1. Connect 12V with terminal (3) and the ground with the
terminal (6).
2. Send the signal to the terminal (4)
2WD " 4WD less than 2.4V
4WD " 2WD more than 9.0V
3. Confirm the output signal from the terminals (1) & (2)
(2 seconds output)
INPUT
SIGNALOUTPUT SIGNAL
(2 seconds)
412
2WD " 4WDLess than
2.4V0V12V
4WD " 2WDMore than
9.0V12V0V
4. If the trouble occurs afther above test, charge the
Axle Disconnect Controller to the new one.

4B1±7
DRIVELINE CONTROL SYSTEM
Shift On The Fly Controller
Shift On The Fly Controller and Associated Parts
828RY00003
Legend
(1) Nut(2) SOF Controller
(3) Connector
Removal
1. Disconnect the battery ground cable.
2. Remove the front console assembly.
Refer to
Consoles in Body and Accessories section.
3. Disconnect the connector from the controller.
4. Remove the nut.
5. Remove the controller.
Installation
To install, follow the removal steps in the reverse order,
noting the following points.
Torque: Nut (1) 8 N´m (69 Ib in)

4B2±1
DRIVE LINE CONTROL SYSTEM (TOD)
AXIOM
DRIVELINE/AXLE
DRIVELINE CONTROL SYSTEM (TOD)
CONTENTS
Service Precaution 4B2±1. . . . . . . . . . . . . . . . . . . . . .
General Description 4B2±2. . . . . . . . . . . . . . . . . . . . .
Transfer Position and Drive Mode 4B2±2. . . . . . . .
TOD Control 4B2±3. . . . . . . . . . . . . . . . . . . . . . . . . .
TOD Indicator Control 4B2±3. . . . . . . . . . . . . . . . . .
Abbreviations 4B2±3. . . . . . . . . . . . . . . . . . . . . . . . .
System Components 4B2±4. . . . . . . . . . . . . . . . . . . .
Parts Location 4B2±4. . . . . . . . . . . . . . . . . . . . . . . .
Front and Rear Speed Sensors 4B2±5. . . . . . . . . .
Electromagnetic Coil 4B2±5. . . . . . . . . . . . . . . . . . .
Multi Plate Disk Clutch Pack 4B2±5. . . . . . . . . . . .
Mechanical Lock Sleeve 4B2±5. . . . . . . . . . . . . . . .
High-Low Planetary Gear Set 4B2±6. . . . . . . . . . .
4H and 4L Switch 4B2±6. . . . . . . . . . . . . . . . . . . . . .
Transfer Connector (12-pin type) 4B2±6. . . . . . . .
Transfer Connector (8-pin type) 4B2±6. . . . . . . . .
TOD Indicator Lamps
(on the instrument panel) 4B2±7. . . . . . . . . . . . . .
Check Lamp 4B2±7. . . . . . . . . . . . . . . . . . . . . . . . . .
TOD ECU 4B2±8. . . . . . . . . . . . . . . . . . . . . . . . . . . .
High-Low Shift Motor 4B2±9. . . . . . . . . . . . . . . . . . .
Motor Position and Encoder Position Code 4B2±10
Encode Position Plate 4B2±10. . . . . . . . . . . . . . . . . .
Shift High Range and Low Range 4B2±10. . . . . . . . Functions of TOD Switch and Indicator
Lamp 4B2±11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TOD Switch and Indication of Drive Mode 4B2±11.
Check Lamp 4B2±13. . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnosis 4B2±14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Information Diagnosis 4B2±14. . . . . . . . . .
Self-diagnosis 4B2±14. . . . . . . . . . . . . . . . . . . . . . . . .
Precautions on Diagnosis 4B2±16. . . . . . . . . . . . . . .
Basic Diagnostic Flow Chart 4B2±18. . . . . . . . . . . . . .
Parts Location 4B2±19. . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Diagram 4B2±20. . . . . . . . . . . . . . . . . . . . . . . . .
Connector List 4B2±24. . . . . . . . . . . . . . . . . . . . . . . . . .
Checking Failed Pin 4B2±26. . . . . . . . . . . . . . . . . . . . .
Connector Pin Assignment 4B2±26. . . . . . . . . . . . . .
Reference 4B2±28. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking Failed TOD Control Unit Pin 4B2±30. . . . .
Tech 2 Scan Tool 4B2±32. . . . . . . . . . . . . . . . . . . . . .
Getting Started 4B2±33. . . . . . . . . . . . . . . . . . . . . . . .
Operating Procedure 4B2±33. . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Codes 4B2±35. . . . . . . . . . . . . . . .
Diagnosis from Trouble Codes 4B2±36. . . . . . . . . . . .
Trouble Diagnosis Depending on The Status
of TOD Indicator 4B2±67. . . . . . . . . . . . . . . . . . . . . . . .
Diagnosis from Symptom 4B2±102. . . . . . . . . . . . . . . . .
Service Precaution
WARNING: THIS VEHICLE HAS A SUPPLEMENTAL
RESTRAINT SYSTEM (SRS). REFER TO THE SRS
COMPONENT AND WIRING LOCATION VIEW IN
ORDER TO DETERMINE WHETHER YOU ARE
PERFORMING SERVICE ON OR NEAR THE SRS
COMPONENTS OR THE SRS WIRING. WHEN YOU
ARE PERFORMING SERVICE ON OR NEAR THE SRS
COMPONENTS OR THE SRS WIRING, REFER TO
THE SRS SERVICE INFORMATION. FAILURE TO
FOLLOW WARNINGS COULD RESULT IN POSSIBLE
AIR BAG DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.CAUTION: Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE SPECIFIED, do not
use supplemental coatings (Paints, greases, or other
corrosion inhibitors) on threaded fasteners or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force, and may damage the fastener. When
you install fasteners, use the correct tightening
sequence and specifications. Following these
instructions can help you avoid damage to parts and
systems.

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±2
General Description
412R200008
TOD (Torque on Demand) system is traction state control
system to vehicle.
Transfer Position and Drive Mode
Three drive modes can be selected through operation of
TOD switch and transfer lever.
Transfer Position
TOD SWITCHModeDrive mode
HIGH2HRWDRear wheel drive
TOD4WD
(HIGH)Electronically controlled torque split
four wheel drive
LOW4L4WD
(LOW)Low-speed mechanical lock-up four
wheel drive
The electronic control unit (ECU) judges the signals from
the TOD switch and controls the transfer drive mode and
shift-on-the-fly system status.

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

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±4
System Components
Parts Location
A04R200004
Legend
(1) Mechanical Lock Sleeve
(2) Drive Chain
(3) Clutch Pack
(4) Electromagnetic Clutch Solenoid
(5) Output Shaft
(6) Rear Output Coupling
(7) Rear Speed Sensor
(8) Drive Sprocket
(9) Spring
(10) Return Spring
(11) Lockup Shift Fork
(12) Front Speed Sensor
(13) High-Low Shift Motor
(14) Driven Sprocket(15) Shift Shaft
(16) Front Output Coupling
(17) Front Output Shaft
(18) Shift Cam
(19) Torsional Spring
(20) High-Low Shift Fork
(21) Shift Rod
(22) Input Shaft
(23) Reduction Hub
(24) High-Low Planetary Gear
(25) High Position
(26) Low Position
(27) Oil Pump
(28) Free Position
(29) Lock Position

4B2±5
DRIVE LINE CONTROL SYSTEM (TOD)
Front and Rear Speed Sensors
The sensors are built in the transfer case, and detect the
rotation of rotors directly coupled to the propeller shafts.
Thirty rectangular pulses are output per one rotation of
the propeller shaft.
261RW045
Electromagnetic Coil
Receives the duty signals from the TOD control unit and
controls the pressing force of the clutch pressure cam.
261RW044
Multi Plate Disk Clutch Pack
Transmits the torque determined by the clutch pressing
force to the front propeller shaft via the front drive chain.
262RW029
Mechanical Lock Sleeve
Couples the front and rear propeller shaft mechanically
when the transfer shaft is in the 4L position.
262RW028