4WD ISUZU AXIOM 2002 Service Repair Manual

0A±12
GENERAL INFORMATION
Abbreviations Charts
List of automotive abbreviations which may be used
in this manual
A Ð Ampere(s)
ABS Ð Antilock Brake System
AC Ð Alternating Current
A/C Ð Air Conditioning
ACCEL Ð Accelerator
ACC Ð Accessory
ACL Ð Air Cleaner
Adj Ð Adjust
A/F Ð Air Fuel Ratio
AIR Ð Secondary Air Injection System
Alt Ð Altitude
AMP Ð Ampere(s)
ANT Ð Antenna
ASM Ð Assembly
A/T Ð Automatic Transmission/Transaxle
ATDC Ð After Top Dead Center
ATF Ð Automatic Transmission Fluid
Auth Ð Authority
Auto Ð Automatic
BARO Ð Barometric Pressure
Bat Ð Battery
B+ Ð Battery Positive Voltage
Bbl Ð Barrel
BHP Ð Brake Horsepower
BPT Ð Backpressure Transducer
BTDC Ð Before Top Dead Center

C Ð Degrees Celsius
CAC Ð Charge Air Cooler
Calif Ð California
cc Ð Cubic Centimeter
CID Ð Cubic Inch Displacement
CKP Ð Crankshaft Position
CL Ð Closed Loop
CLCC Ð Closed Loop Carburetor Control
CMP Ð Camshaft Position
CO Ð Carbon Monoxide
Coax Ð Coaxial
Conn Ð Connector
Conv Ð Converter
Crank Ð Crankshaft
Cu. In. Ð Cubic Inch
CV Ð Constant Velocity
Cyl Ð Cylinder(s)
DI Ð Distributor Ignition
Diff Ð Differential
Dist Ð Distributor
DLC Ð Data Link Connector
DOHC Ð Double Overhead Camshaft
DTC Ð Diagnostic Trouble Code
DTM Ð Diagnostic Test Mode
DTT Ð Diagnostic Test Terminal
DVM Ð Digital Voltmeter (10 meg.)
DVOM Ð Digital Volt Ohmmeter
EBCM Ð Electronic Brake Control Module
ECM Ð Engine Control Module
ECT Ð Engine Coolant Temperature
EEPROM Ð Electronically Erasable Programmable
Read Only Memory
EGR Ð Exhaust Gas Recirculation
EI Ð Electronic Ignition
ETR Ð Electronically Tuned Receiver
EVAP Ð Evaporation EmissionExh Ð Exhaust

F Ð Degrees Fahrenheit
Fed Ð Federal (All States Except Calif.)
FF Ð Front Drive Front Engine
FL Ð Fusible Link
FLW Ð Fusible Link Wire
FP Ð Fuel Pump
FRT Ð Front
ft Ð Foot
FWD Ð Front Wheel Drive
4WD Ð Four Wheel Drive
4 x 4 Ð Four Wheel Drive
4 A/T Ð Four Speed Automatic Transmission/Transaxle
Gal Ð Gallon
GEN Ð Generator
GND Ð Ground
Gov Ð Governor
g Ð Gram
Harn Ð Harness
HC Ð Hydrocarbons
HD Ð Heavy Duty
Hg Ð Hydrargyrum (Mercury)
HiAlt Ð High Altitude
HO2S Ð Heated Oxygen Sensor
HVAC Ð Heater±Vent±Air±Conditioning
IAC Ð Idle Air Control
IAT Ð Intake Air Temperature
IC Ð Integrated Circuit / Ignition Control
ID Ð Identification / Inside Diameter
IGN Ð Ignition
INJ Ð Injection
IP Ð Instrument Panel
IPC Ð Instrument Panel Cluster
Int Ð Intake
ISC Ð Idle Speed Control
J/B Ð Junction Block
kg Ð Kilograms
km Ð Kilometers
km/h Ð Kilometer per Hour
kPa Ð Kilopascals
kV Ð Kilovolts (thousands of volts)
kW Ð Kilowatts
KS Ð Knock Sensor
L Ð Liter
lb ft Ð Foot Pounds
lb in Ð Inch Pounds
LF Ð Left Front
LH Ð Left Hand
LR ÐLeft Rear
LS Ð Left Side
LWB Ð Long Wheel Base
L±4 Ð In±Line Four Cylinder Engine
MAF Ð Mass Air Flow
MAN Ð Manual
MAP Ð Manifold Absolute Pressure
Max Ð Maximum
MC Ð Mixture Control
MFI Ð Multiport Fuel Injection
MIL Ð Malfunction Indicator Lamp
Min Ð Minimum
mm Ð Millimeter
MPG Ð Miles Per Gallon
MPH Ð Miles Per Hour
M/T Ð Manual Transmission/Transaxle
MV Ð Millivolt

3C±10FRONT SUSPENSION
Knuckle
Knuckle and Associated Parts
410RW006
Legend
(1) Torsion Bar
(2) Lower Ball Joint, Nut and Cotter Pin
(3) Back Plate
(4) Knuckle Assembly
(5) Knuckle(6) Needle Bearing (4WD MODEL)
(7) Thrust Washer (4WD MODEL)
(8) Oil Seal (4WD MODEL)
(9) Upper Ball Joint, Nut and Cotter Pin
(10) Wheel Speed Sensor
Removal
1. Raise the vehicle and support the frame with suitable
safety stands.
2. Remove wheel and tire assembly. Refer to
Wheel in
this section.
3. Remove the brake caliper. Refer to Disc Brakes in
Brake section.
4. Remove the hub assembly. Refer to Front Hub and
Disk in this section.
5. Remove tie±rod end from the knuckle. Refer to Power
Steering Unit in Steering section.
6. Remove the speed sensor from the knuckle.
7. Loosen torsion bar by height control arm adjust bolt,
then remove torsion bar. Refer to
Torsion Bar in this
section.
8. Remove wheel speed sensor.

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±3
DRIVELINE CONTROL SYSTEM
Normal Operation
The axle disconnect controller is driven by the signal from
TOD control unit and the axle motor actuator connects (or
disconnects when the 4WD switch is deactivated) the
front wheels to the front axles.
Time Chart of Shifting Under Normal Condition
F04R200002
4WD out signal to other Electronic Brake Control
Module : TOD Control Unit of shift on the fly sends 4WD
out signal to other Electronic Brake Control Module as
below.
4WD out signal
(Period)
Vehicle ConditionTransfer position switchFront axle switch
120 ms2WD2WD (Open)2WD (Open)
240 ms4WD4WD (Close)4WD (Close)

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

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.

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±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

4B2±27
DRIVE LINE CONTROL SYSTEM (TOD)
No. CONTENTSNAME
26MTR POS1Shift Motor Position 1
27POSCAT Position C
28POSAAT Position A
29DIAGDiagnostic Input
30TOD SW ATOD Switch A (2H)
314H SW4H Switch Input
32FT. SIGFront Speed Signal
33ABS INABS In
34VBPower Bat
35MTR H-LPower Shift Motor H-L
364WD OUT4WD Signal Output
37BRAKE SWBrake Switch Input
38MTR POS4Shift Motor Position 4
39MTR POS2Shift Motor Position 2
40LIGHTING SWLighting Switch Input
41POSBAT Position B
42AXLE SWAxle Switch Input
43TOD SWBTOD Switch B (4L)
444L SW4L Switch Input
45RR. SIGRear Speed Signal
46GND. 1ECU Ground 1
47GND. 2ECU Ground 2
48MTR L-HPower Shift Motor L-H

4B2±31
DRIVE LINE CONTROL SYSTEM (TOD)
Check
Pin
No.Note Standard Value Measure
between
Pin No. Unit
Scale/
Range Engine
State Ignition
Switch
Position Circuit to be
tested
364WD
OUTOFFSTOP
36, 477 ~12 k
Disconnect battery GND terminal
11EMC(+)OFFSTOP
11, 221.0 ~5.0
Disconnect battery GND terminal
30TOD SW
AONSTOPDCV30 (+), 47
(±)SW: TOD, 4L: 0
V
SW:2H:8.0 ~
14.5 V
43TOD
SWBONSTOPDCV43 (+), 47
(±)SW: 2H,
TOD:0V
SW: 4L: 8.0 ~
14.5V
40LIGHTONSTOPDCV40 (+), 47
(±)SW OFF : 0 V
SW ON : 8.0 ~
14.5 V
19IND BONSTOPDCV19 (+), 47
(±)8.0 ~14.5 VWhen the indicator lamp is turned
off
8IND CONSTOPDCV8 (+), 47
(±)8.0 ~ 14.5 VWhen the indicator lamp is turned
off
27AT POSCONSTOPDCV27 (+), 47
(±)ON:D, 3, 2, 1
OFF:PRNON:8.0 ~ 14.5 V
OFF:0V
41AT POSBONSTOPDCV41 (+), 47
(±)ON:R, N, D, 3
OFF:P, 2, 1ON:8.0 ~ 14.5 V
OFF:0V
28AT POSAONSTOPDCV28 (+), 47
(±)ON:P, R, 3, 2
OFF:N, D, 1ON:8.0 ~ 14.5 V
OFF:0V
2ENG REVONRUNms2, 47Waveform
(PWM)50 ms (1000 rpm)