brake sensor ISUZU AXIOM 2002 Service User Guide

DIFFERENTIAL (REAR)4A2±23
Backlash Adjustment
1. Install the differential case assembly and bearing
caps.
2. Rotate the case several times to seat the bearings.
3. Remove the spreader.
4. Install the side bearing cap bolts.
Tighten side bearing cap bolts
Torque: 108 N´m (80 lb ft)
5. Install a dial indicator to the case using a magnetic
base.
6. Place the indicator stem at the heel end of a tooth.

Set the dial indicator so that the stem is in line with
the gear rotation and perpendicular to the tooth
angle.
425RS087
7. Check and record the backlash at three points around
the ring gear.

The pinion must be held stationary when checking
backlash.

The backlash should be the same at each point
within 0.07 mm (0.003 in). If the backlash varies
more than 0.07 mm (0.003 in), check for burrs, a
distorted case flange, or uneven bolting conditions.
8. Backlash at the minimum lash point measured should
be between 0.13 and 0.20 mm (0.005 and 0.008 in)
for all new gear sets.
9. If the backlash is not within specifications, move the
ring gear in or out from the pinion by increasing the
thickness of one shims, and decreasing the thickness
of the other shim by the same amount.
This will maintain the correct rear axls side bearing
preload.

Moving 0.05 mm (0.002 in) worth of shim from one
side of the differential to the other will change the
backlash adjustment by 0.03 mm (0.001 in).
10. After obtaining correct tooth contact described in
later, install ABS speed sensor.11. Install the cover with sealant.
Torque: 40 N´m (30 lb ft)
12. Fill the axle lubricant.
Gear Tooth Pattern Check
Checking the ring gear to pinion tooth pattern is to be
done only after setting up the axle according to the
methods in this section. The pattern check is NEVER to
be used as an initial check, or instead of checking pinion
depth and backlash adjustments.
This check is only to be verify the correct adjustment of
the gear set after set up.
425RS038
Legend
(1) Heel
(2) Toe
(3) Concave Side (Coast)
(4) Convex Side (Drive)
1. Wipe all oil out of the carrier, and carefully clean each
tooth of the ring gear.
2. Use gear marking compound 1052351 or equivalent
and apply this mixture sparingly to all ring gear teeth,
using a medium-stiff brush. When properly used, the
area of pinion tooth contact will be visible when hand
load is applied.
3. Tighten the bearing cap bolts to the specified torque.
4. Expand the brake shoes until a torque of 54 to 68 N´m
(40 to 50 lb ft.) is required to turn the pinion. A test
made without loading the gears will not give a
satisfactory pattern. Turn the pinion flange with a
wrench so that the ring gear rotates one full
revolution, then reverse the rotation so that the ring
gear rotates one revolution in the opposite direction.
5. Observe the pattern on the ring gear teeth and
compare this with figure.

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±30
Checking Failed TOD Control Unit Pin
NOTE:
1. Unplug the ECU connector and the pins, unless
otherwise specified.
2. Before removing the ECU, turn off the ignition switch.
3. If the standard values are not observed, check the
pins with other testers.
Check
Pin
No.Circuit to be
testedIgnition
Switch
PositionEngine
StateUnit
Scale/
RangeMeasure
between
Pin No.Standard ValueNote
22P-GNDOFFSTOP
22, 47Continuity : OK
46GNDIOFFSTOP
46, 47Continuity : OK
47GND 2OFFSTOP
47, GNDContinuity : OK
314H SWOFFSTOP
31, 47No continuity
(high, 4L) : OK
444L SWOFFSTOP
44, 47No continuity
(high) and
continuity (4L) :
OK
42AXLE SWONRUN
42, 47Continuity(TOD,
4L) : OKRemove ECU connector and start
the engine. Move the vehicle forth
and back to connect axle surely.
29DIAGOFFSTOP
29 (TOD),
8 (DLC
Connec-
tor)Continuity : OKDLC connector terminal 8
7IND.AONSTOPDCV7 (+), 47
(±)8.0 ~14.5 Vwhen the indicator lamp is turned
off.
20CHECK
TODONSTOPDCV20 (+), 47
(±)8.0 ~14.5 VWhen the indicator lamp is turned
off.
33ABS INONSTOPDCV33 (+), 47
(±)6.0 ~11.0 V
12REFONSTOPDCV12 (+), 47
(±)5 ~9 VConnect ECU
32FRT.(+)ONSTOPDCV32 (+), 47
(±)0.7 ~6 VConnect ECU and move the
vehicle (off one tooth of speed
sensor ring) making sure of
voltage change.
45RR.(+)ONSTOPDCV45 (+), 47
(±)0.7 ~6 VConnect ECU and move the
vehicle (off one tooth of speed
sensor ring) making sure of
voltage change.
13COM(-)ONSTOPDCV13 (+), 47
(±)0VConnect ECU
14VIGONSTOPDCV14 (+), 47
(±)8 ~14.5 V
34VBOFFSTOPDCV34 (+), 47
(±)8.0 ~14.5 V
37BRAKE
SWOFFSTOPDCV37 (+), 47
(±)8 ~14.5 VPress brake pedal
15TPSONSTOPDCV15 (+), 47
(±)PWM duty cycle
10%(MAX) ± 90
%(MIN)Step on the accelerator pedal and
make sure that duty cycle
changes.

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±102
Diagnosis from Symptom
Troubles that are not indicated by the warning lamp are
listed in the table below. These troubles are caused by the
faults that cannot be detected by the self-diagnostic
function of the control unit.
If this type of trouble is observed, interview the customer
and conduct test runs to reproduce the trouble,
cross-check the reported trouble with the listed
phenomena, and diagnose and analyze the trouble on the
item by item basis.
PhenomenaMajor causeCorrective action
1The tight corner braking is
observed when the vehicle is
subject to full steering.
The standard tires are not used.

The tire pressure is incorrect.

The tires are worn inuniformity.

The transfer or wiring is
imperfect.

The limited slip differential is
failed.Check and recondition the
vehicle according to Chart 1.
2Even if the TOD switch is selected
to the TOD position, the F4WD
mode is not active, resulting in
remarkable rear wheel spin.
The transfer or wiring is
imperfect.

The shift on the fly system is
failed.Check and recondition the
vehicle according to Chart 2.
3
When the TOD switch is
selected to the TOD position,
the drive resistance of the
F4WD system is too large to get
sufficient running speed.

Noised drive line.
The standard tires are not used.

The tires are worn inuniformity.

The transfer or wiring is
imperfect.

The limited slip differential is
failed. Check and recondition the
vehicle according to Chart 1.
4The shift on the fly system (front
axle disconnect) generates gear
noises.
The wiring is imperfect.

The shift on the fly system is
failed.Check and recondition the
vehicle according to Chart 3.
5The braking distance gets long
even when the ABS is active.
The wiring is imperfect.

The ABS is failed.Check and recondition the
vehicle according to Chart 4.
6The transfer does not change to the
low range from the high range.
The transfer or wiring is
imperfect.

The TOD switch is imperfect.

The AT inhibitor switch is
imperfect.
Check and recondition the
vehicle according to chart 5.
7The transfer does not change to the
high range from the low range.
im erfect.

The brake switch is imperfect.

The engine speed signal is
imperfect.

The speed sensor is imperfect.
Check and recondition the
vehicle according to chart 6.
8The transfer stays neutral and the
vehicle does not run.
The transfer is imperfect.Check and recondition the
vehicle according to chart 7.

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±104
StepActionYe sNo
1Are the front and rear tires in specified size?
Go to Step 2
Replace the tires
with specified
ones, and service
the new tires.
Go to
Step 16
2Is the tire pressure correct?
Go to Step 3
Inflate the tires
with specified
pressure.
Go to
Step 16
3Are the tires free from abnormal wear?
Go to Step 4
Replace the tires
with specified
ones, and service
the new tires.
Go to
Step 16
4Are different types of tires used?
Go to Step 5
Replace the tires
with specified
ones, and service
the new tires.
Go to
Step 16
51. Start the engine.
2. Select the TOD switch to the TOD position.
3. Fully turn the steering to the left (or right) end, and select the D
range and start the creep run.
Does the tight corner braking occur? Is the judder with chug-chug
sound observed? * Use caution on the operation.
Go to Step 6 Go to Step 11
61. Select the TOD switch to the 2H position.
2. Fully turn the steering to the left (or right) end, and select the D
range and start the creep run.
Does the tight corner braking occur? Is the judder with chug-chug
sound observed? * Use caution on the operation.
Go to Step 7 Go to Step 14
7Is an LSD mounted to the rear differential? Go to Step 8 Go to Step 9
8Is the genuine LSD oil used in the rear differential?
Go to Step 9
Replace the
differential oil.
Go to
Step 16
9Does the engine output the power correctly?
Go to Step 10
Check the
engine.
Go to
Step 16
10Do the speed sensors work correctly? (Check trouble codes.)The ECU has
failed. Replace
the ECU.
Go to
Step 16
Replace the
speed sensors.
Go to
Step 16
11Is the tight corner braking observed only when the brake is
applied?
Go to Step 12
Conduct full
steering under
WOT.
Go to
Step 5
121. Turn on the starter switch.
Is 8 ~ 10 V observed between terminals 33 and 47?
Go to Step 13
Repair the circuit
of the ECU
connector
terminal 33 (ABS
IN).
Go to
Step 16

4C±3 DRIVE SHAFT SYSTEM
Front Hub and Disc (2WD Model)
Disassembled View
411RX001
Legend
(1) Bolt
(2) Cover and Gasket
(3) Lock Washer and Lock Screw
(4) Hub Nut
(5) Outer Bearing(6) Hub and Disc Assembly
(7) ABS Sensor Ring
(8) Inner Bearing
(9) Oil Seal
(10) Bolt
(11) Wheel Pin
Disassembly
1. Before disassembly, jack up the front of vehicle and
support frame with jack stands.
2. Remove the two bolts from the rear side of the
knuckle arm, then remove the brake caliper, with the
brake hose attached.
Use a wire to attach the brake caliper to the upper link.
Refer to
Disk Brakes in Brake section.
3. Remove cover bolt.
4. Remove cover and gasket.
5. Remove lock washer and Lock screw.
6. Remove hub nut, using front hub nut wrench
J±36827.
901RW054

4C±4
DRIVE SHAFT SYSTEM
7. Remove hub and disc assembly.
8. Remove ABS sensor ring.
9. Remove outer bearing.
10. Remove oil seal.
11. Remove inner bearing.
12. Use a brass bar to remove the outer bearing outer
race(1), oil seal, inner bearing and inner bearing outer
race(2) from the hub.
411RS002
13. Remove bolt.
14. If necessary, replace the wheel pin in the following
manner.

Scribe mark(1) on hub to disc before disassembly
to insure proper assembly.
411RS003

Clamp hub and disc assembly in vise, using
protective pads. Remove six(6) disc-to-hub
retaining bolts.
411RS021

Place hub on a suitable work surface and remove
wheel studs, as required, using a hammer.
411RS004
Inspection and Repair
Make necessary correction or parts replacement if wear,
damage, corrosion or any other abnormal condition are
found through inspection.
Check the following parts.

Hub

Hub bearing oil seal

Knuckle spindle

Disc

Caliper

ABS sensor ring
For inspection and servicing of disc caliper and related
parts, refer to
Disc Brake in Brake section.

4C±8
DRIVE SHAFT SYSTEM
Front Hub and Disc (4WD Model)
Disassembled View
411RW001
Legend
(1) Bolt
(2) Cap
(3) Snap Ring and Shim
(4) Hub Flange
(5) Lock Washer and Lock Screw
(6) Hub Nut(7) Outer Bearing
(8) Bolt
(9) Hub and Disc Assembly
(10) Wheel Pin
(11) ABS Sensor Ring
(12) Inner Bearing
(13) Oil Seal
Disassembly
1. Before disassembly, select the 2WD position with the
4WD switch.
2. Jack up the front of vehicle and support frame with
jack attached.3. Remove the two bolts from the rear side of the
knuckle arm, then remove the brake caliper, with the
brake hose attached.
Use a wire to attach the brake caliper to the upper link.
Refer to
Disk Brakes in Brake section.
4. Remove Bolt.
5. Remove cap.

4C±10
DRIVE SHAFT SYSTEM
Inspection and Repair
Make necessary correction or parts replacement if wear,
damage, corrosion or any other abnormal condition are
found through inspection.
Check the following parts.

Hub

Hub bearing, oil seal

Knuckle spindle

Disc

Caliper

Shift on the fly system parts (Cap, Hub flange, Shim,
Snap ring)

ABS sensor ring
For inspection and servicing of disc caliper and related
parts, refer to
Disc Brakes in Brake section.
Reassembly
1. Install wheel pin.

Place the hub on a wood workbench or a block of
wood approx. 6º by 6º to protect the wheel stud
ends and threads.

Insert a wheel stud using a hammer.
NOTE: Be sure the wheel stud is started squarely and
seats completely.
411RS005
2. Align scribe marks(1) and attach the hub to the disc,
then tighten the bolts to the specified torque.
Torque: 103 N´m (76 lb ft)
411RS003
3. Install inner bearing.
Install the outer race by driving it into the hub by using
insatller J±36829 and grip J±8092.
901RW055

4C±48
DRIVE SHAFT SYSTEM
Reassembly
1. Install wheel pin.
411RS005

Place hub on a wood workbench or a block of wood
approx. 6º by 6º to protect the wheel stud ends and
threads.

Install wheel stud, using a hammer.
NOTE: Be sure wheel stud is started squarely and seats
completely.
2. Install the hub unit bearing to the knuckle.
Tighten the bolts to the specified torque.
Hub unit bearing bolt
Torque: 103+10 N´m (10.5 + 1 kg´m)
If there is rust on the bearing and knuckle contact
surfaces, use sandpaper to remove it before installation.
3. Install the ABS sensor connector.
4. Install the disc rotor.
5. Install the brake caliper to the bracket.
Refer to
Front disc caliper assembly in Section 5C of this
Manual.