Rear axle ISUZU TROOPER 1998 Service Service Manual

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±86
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 ob-
served 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 ve-
hicle according to Chart 1.
2Even if the 4WD SW is select to the
4WD position, the 4WD 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 ve-
hicle according to Chart 2.
3
When the 4WD SW is select to
the 4WD position, the drive
resistance of the 4WD system is
too large to get sufficient running
speed.

Noised drive line.
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 Check and recondition the ve-
hicle according to Chart 1.
4The shift on the fly system (front
axle) generates gear noises.
The wiring is imperfect.

The full automatic free wheel
hub is failed.Check and recondition the ve-
hicle 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 ve-
hicle according to Chart 4.

4C±1 DRIVE SHAFT SYSTEM
DRIVELINE/AXLE
DRIVE SHAFT SYSTEM
CONTENTS
Service Precaution 4C±2. . . . . . . . . . . . . . . . . . . . . .
General Description 4C±2. . . . . . . . . . . . . . . . . . . . .
Diagnosis 4C±3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Axle Shaft 4C±4. . . . . . . . . . . . . . . . . . . . . . . . .
Rear Axle Shaft and Associated Parts 4C±4. . . .
Removal 4C±4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 4C±5. . . . . . . . . . . . . . . . . .
Oil Seal Replacement 4C±6. . . . . . . . . . . . . . . . . .
Installation 4C±6. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Tools 4C±8. . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Hub and Disc (with Shift on the Fly) 4C±9. .
Disassembled View 4C±9. . . . . . . . . . . . . . . . . . . .
Disassembly 4C±9. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 4C±10. . . . . . . . . . . . . . . . . .
Reassembly 4C±11. . . . . . . . . . . . . . . . . . . . . . . . . .
Front Hub and Disc with Manual Locking Hub 4C±14
Disassembled View 4C±14. . . . . . . . . . . . . . . . . . . .
Disassembly 4C±14. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 4C±16. . . . . . . . . . . . . . . . . .
Reassembly 4C±16. . . . . . . . . . . . . . . . . . . . . . . . . .
Main Data and Specifications 4C±20. . . . . . . . . . . . .
Special Tools 4C±21. . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Drive Shaft Joint 4C±22. . . . . . . . . . . . . . . . . . .
Front Drive Shaft Joints Replacement 4C±22. . . .
Front Axle Drive Shaft 4C±23. . . . . . . . . . . . . . . . . . .
Front Axle Drive Shaft and Associated
Parts 4C±23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly 4C±24. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 4C±25. . . . . . . . . . . . . . . . . .
Bushing Replacement 4C±25. . . . . . . . . . . . . . . . . . Reassembly 4C±26. . . . . . . . . . . . . . . . . . . . . . . . . .
Shift On The Fly System 4C±28. . . . . . . . . . . . . . . . .
Shift On The Fly System and Associated
Parts 4C±28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly 4C±28. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 4C±30. . . . . . . . . . . . . . . . . .
Main Data and Specifications 4C±35. . . . . . . . . . .
Special Tools 4C±36. . . . . . . . . . . . . . . . . . . . . . . . . .
Front Propeller Shaft 4C±37. . . . . . . . . . . . . . . . . . . . .
General Description 4C±37. . . . . . . . . . . . . . . . . . . . .
Front Propeller Shaft and Associated Parts 4C±38
Removal 4C±38. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 4C±39. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly (Except TOD 4y4) 4C±40. . . . . . . . .
Universal Joint Disassembly 4C±41. . . . . . . . . . . .
Inspection and Repair 4C±42. . . . . . . . . . . . . . . . . .
Universal Joint Reassembly 4C±45. . . . . . . . . . . . .
Reassembly (Except TOD 4y4) 4C±46. . . . . . . . . .
Main Data and Specifications 4C±47. . . . . . . . . . .
Rear Propeller Shaft 4C±48. . . . . . . . . . . . . . . . . . . . .
General Description 4C±48. . . . . . . . . . . . . . . . . . . . .
Rear Propeller Shaft and Associated Parts 4C±48
Removal 4C±49. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 4C±49. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly 4C±50. . . . . . . . . . . . . . . . . . . . . . . . . .
Universal Joint Disassembly 4C±51. . . . . . . . . . . .
Inspection and Repair 4C±52. . . . . . . . . . . . . . . . . .
Universal Joint Reassembly 4C±53. . . . . . . . . . . . .
Reassembly 4C±54. . . . . . . . . . . . . . . . . . . . . . . . . .
Main Data and Specifications 4C±55. . . . . . . . . . .

4C±2
DRIVE SHAFT SYSTEM
Service Precaution
WARNING: I F S O E Q U IPPED WITH 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.
General Description
This publication contains essential removal, installation,
adjustment and maintenance procedures.
The front axle utilizes a central disconnect type front
axle/transfer case system.
The drive axles are completely flexible assemblies,
consisting of inner and outer constant velocity (CV) drive
shaft joints connected by an axle shaft.
For description of propeller shaft and universal joint, refer
to Front/Rear Propeller Shaft in this section.

4C±3 DRIVE SHAFT SYSTEM
Diagnosis
ConditionPossible causeCorrection
Oil Leak At Front AxleWorn or defective oil seal.Replace the oil seal.
Front axle housing cracked.Repair or replace.
Oil Leak At Pinion ShaftToo much gear oil.Correct the oil level.
Oil seal worn or defective.Replace the oil seal.
Pinion flange loose or damaged.Tighten or replace.
Noises In Front Axle Drive Shaft
JointBroken or worn drive shaft joints and
bellows (BJ and DOJ).Replace the drive shaft joints and
bellows.
ªClankº When Accelerating From
ªCoastºLoose drive shaft joint to output shaft
bolts.Tighten.
Damaged inner drive shaft joint.Replace.
Shudder or Vibration During
Acceleration
Excessive drive shaft joint angle.Repair.
AccelerationWorn or damaged drive shaft joints.Replace.
Sticking spider assembly (inner drive
shaft joint).Lubricate or replace.
Sticking joint assembly (outer drive
shaft joint).Lubricate or replace.
Vibration At Highway SpeedsOut of balance or out of round tires.Balance or replace.
Front end out of alignment.Align.
Noises in Front AxleInsufficient gear oil.Replenish the gear oil.
Wrong or poor grade gear oil.Replace the gear oil.
Drive pinion to ring gear backlash
incorrect.Adjust the backlash.
Worn or chipped ring gear, pinion
gear or side gear.Replace the ring gear, pinion gear or
side gear.
Pinion shaft bearing worn.Replace the pinion shaft bearing.
Wheel bearing worn.Replace the wheel bearing.
Differential bearing loose or worn.Tighten or replace.
Wanders and PullsWheel bearing preload too tight.Adjust the wheel bearing preload.
Incorrect front alignment.Adjust the front alignment.
Steering linkage loose or worn.Tighten or replace.
Steering gear out of adjustment.Adjust or replace the steering gear.
Tire worn or improperly inflated.Adjust the inflation or replace.
Front or rear suspension parts loose
or broken.Tighten or replace.
Front Wheel ShimmyWheel bearing worn or improperly
adjusted.Adjust or replace.
Incorrect front alignment.Adjust the front alignment.
Worn ball joint or bush.Replace the ball joint or bush.
Steering linkage loose or worn.Tighten or replace.
Steering gear out of adjustment.Tighten or replace.
Tire worn or improperly inflated.Replace or adjust the inflation.
Shock absorber worn.Replace the shock absorber.

4C±4
DRIVE SHAFT SYSTEM
Rear Axle Shaft
Rear Axle Shaft and Associated Parts
420RW014
Legend
(1) Brake Caliper
(2) Brake Disc
(3) Wheel Pin
(4) Axle Shaft Assembly
(5) Back Plate
(6) Parking Brake Assembly
(7) Bearing Holder(8) Bearing
(9) Retainer
(10) Snap Ring
(11) Bolt
(12) Nut
(13) Antilock Brake System (ABS) Speed Sensor (if
so equipped)
Removal
1. Raise the vehicle.
2. Remove tires and wheels. Refer to Wheel in Steering
section.3. Remove brake caliper. Use a wire to attach the brake
caliper to the frame. Refer to Disk Brakes in Brake
section.
4. Remove brake disc.
5. Remove ABS sensor (if so equipped).
6. Remove Parking brake assembly. Refer to Parking
Brakes in Brake section.

4C±38
DRIVE SHAFT SYSTEM
Front Propeller Shaft and Associated Parts
401RW058
Legend
(1) Bolt, Nut and Washer (Front Axle Side)
(2) Front Propeller Shaft
(3) Bolt, Nut and Washer (Transfer Side)(4) Front Propeller Shaft (with TOD)
(5) Coupling
(6) LJ Constant Velocity Joint
(7) BJ Constant Velocity Joint
Removal
1. Jack up the vehicle and support it on the chassis
stands.
2. Gear shift lever should be placed in neutral position
and parking brake released.
3. Remove the exhaust and transfer protectors.
NOTE: Apply alignment marks on the flange at the front
propeller shaft both front and rear side.
401RS020

4C±49 DRIVE SHAFT SYSTEM
Removal
1. Jack up the vehicle and support it on the chassis
stands.
2. Gear shift lever should be placed in neutral position
and parking brake released.
NOTE: Apply alignment marks on the flange at the rear
propeller shaft both front and rear side.
401RS023
3. Remove bolt, nut and washer (Rear axle side).
4. Remove bolt, nut and washer (Transfer side).
5. Remove rear propeller shaft.
Installation
NOTE: Never install the shaft assembly backwards.
1. Completely remove the black paint from the
connecting surface of flange coupling on each end of
propeller shaft. Clean so that no foreign matter will be
caught in between.
2. Align the mark which is applied at removal .
Install rear propeller shaft and tighten the bolts to the
specified torque.
Torque: 63 N´m (6.4 kg´m/46 lb ft)3. After installing the propeller shaft, be sure to apply
black paint (1) to exposed area (other than
connecting surface) of the entire surface of flange
coupling .
401RS022

TRANSFER CASE (STANDARD TYPE)
4D1±1
DRIVELINE/AXLE
TRANSFER CASE (STANDARD TYPE)
CONTENTS
Service Precaution 4D1±1. . . . . . . . . . . . . . . . . . . . . .
General Description 4D1±2. . . . . . . . . . . . . . . . . . . . .
Transfer Rear Oil Seal 4D1±8. . . . . . . . . . . . . . . . . . .
Removal 4D1±8. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 4D1±8. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Case Assembly 4D1±9. . . . . . . . . . . . . . . . .
Removal 4D1±9. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 4D1±10. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Rear Cover Assembly
(4WD Switch Model) 4D1±11. . . . . . . . . . . . . . . . . . . .
Transfer Rear Cover Assembly and
Associated Parts 4D1±11. . . . . . . . . . . . . . . . . . . . . .
Removal 4D1±12. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 4D1±13. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly 4D1±16. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 4D1±17. . . . . . . . . . . . . . . . . .
Reassembly 4D1±17. . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Rear Cover Assembly
(Except 4WD Switch Model) 4D1±19. . . . . . . . . . . . . . Transfer Rear Cover Assembly and
Associated Parts 4D1±19. . . . . . . . . . . . . . . . . . . . . .
Removal 4D1±20. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 4D1±20. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly 4D1±23. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 4D1±24. . . . . . . . . . . . . . . . . .
Reassembly 4D1±24. . . . . . . . . . . . . . . . . . . . . . . . . .
Detent, Shift Arm, and Interlock Pin 4D1±26. . . . . . . .
Disassembled View 4D1±26. . . . . . . . . . . . . . . . . . . .
Disassembly 4D1±26. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 4D1±28. . . . . . . . . . . . . . . . . .
Reassembly 4D1±28. . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Case Assembly 4D1±30. . . . . . . . . . . . . . . . .
Disassembled View 4D1±30. . . . . . . . . . . . . . . . . . . .
Disassembly 4D1±31. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 4D1±33. . . . . . . . . . . . . . . . . .
Reassembly 4D1±37. . . . . . . . . . . . . . . . . . . . . . . . . .
Main Data and Specifications 4D1±43. . . . . . . . . . . . .
Special Tools 4D1±46. . . . . . . . . . . . . . . . . . . . . . . . . . .
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.

4D2±1 TRANSFER CASE (TOD)
DRIVELINE/AXLE
TRANSFER CASE (TOD)
CONTENTS
Service Precaution 4D2±1. . . . . . . . . . . . . . . . . . . . . .
Transfer Case Assembly 4D2±2. . . . . . . . . . . . . . . . .
Removal 4D2±2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 4D2±3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Rear Oil Seal 4D2±5. . . . . . . . . . . . . . . . . . .
Transfer Rear Oil Seal and Associated
Parts 4D2±5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 4D2±5. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 4D2±5. . . . . . . . . . . . . . . . . . . . . . . . . . . .
TOD ECU 4D2±7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 4D2±7. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 4D2±7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unit Repair 4D2±8. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection 4D2±8. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Case 4D2±9. . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembled View 4D2±9. . . . . . . . . . . . . . . . . . . .
Disassembly 4D2±9. . . . . . . . . . . . . . . . . . . . . . . . . .
Reassembly 4D2±10. . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Cover Assembly 4D2±12. . . . . . . . . . . . . . . .
Disassembled View 4D2±12. . . . . . . . . . . . . . . . . . . .
Disassembly 4D2±12. . . . . . . . . . . . . . . . . . . . . . . . . .
Reassembly 4D2±14. . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Case Assembly Clutch Pack and
Clutch Cam 4D2±16. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembled View 4D2±16. . . . . . . . . . . . . . . . . . . . Disassembly 4D2±16. . . . . . . . . . . . . . . . . . . . . . . . . .
Sprocket and Mechanical Lock 4D2±18. . . . . . . . . . . .
Disassembled View 4D2±18. . . . . . . . . . . . . . . . . . . .
Disassembly 4D2±18. . . . . . . . . . . . . . . . . . . . . . . . . .
Output Shafts and Shift Control Shaft 4D2±20. . . . . .
Disassembled View 4D2±20. . . . . . . . . . . . . . . . . . . .
Disassembly 4D2±21. . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Case 4D2±23. . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembled View 4D2±23. . . . . . . . . . . . . . . . . . . .
Disassembly 4D2±24. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 4D2±26. . . . . . . . . . . . . . . . . .
Transfer Case 4D2±30. . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembled View 4D2±30. . . . . . . . . . . . . . . . . . . .
Reassembly 4D2±30. . . . . . . . . . . . . . . . . . . . . . . . . .
Output Shafts and Shift Control Shaft 4D2±34. . . . . .
Disassembled View 4D2±34. . . . . . . . . . . . . . . . . . . .
Reassembly 4D2±34. . . . . . . . . . . . . . . . . . . . . . . . . .
Sprocket and Mechanical Lock 4D2±37. . . . . . . . . . . .
Disassembled View 4D2±37. . . . . . . . . . . . . . . . . . . .
Reassembly 4D2±37. . . . . . . . . . . . . . . . . . . . . . . . . .
Clutch Pack and Clutch Cam 4D2±39. . . . . . . . . . . . .
Disassembled View 4D2±39. . . . . . . . . . . . . . . . . . . .
Reassembly 4D2±39. . . . . . . . . . . . . . . . . . . . . . . . . .
Main Data and Specifications 4D2±41. . . . . . . . . . . . .
Special Tools 4D2±43. . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Precaution
WARNING: I F S O E Q U IPPED WITH 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.

5A±4
BRAKE CONTROL SYSTEM
normal braking when a malfunction has occurred in the
ABS.
The EHCU has a self-diagnosing function which can
indicate faulty circuits during diagnosis.
The EHCU is mounted on the engine compartment front
right side. It consists of a Motor, Plunger Pump, Solenoid
Valves and Check Valve.
On the outside, the relay box containing a motor relay and
a valve relay is installed.
Solenoid Valves: Reduces or holds the caliper fluid
pressure for each front disc brake or both rear disc brakes
according to the signal sent from the EHCU.
Reservoir: Temporarily holds the brake fluid that returns
from the front and rear disc brake caliper so that pressure
of front disc brake caliper can be reduced smoothly.
Plunger Pump: Feeds the brake fluid held in the reservoir
to the master cylinder.
Motor: Drives the pump according to the signal from
EHCU.
Check Valve: Controls the brake fluid flow.
ABS Warning Light
821RW033Vehicles equipped with the Anti-lock Brake System have
an amber ªABSº warning light in the instrument panel.
The ªABSº warning light will illuminate if a malfunction in
the Anti-lock Brake System is detected by the Electronic
Hydraulic Control Unit (EHCU). In case of an electronic
malfunction, the EHCU will turn ªONº the ªABSº warning
light and disable the Anti-lock braking function.
The ªABSº light will turn ªONº for approximately three
seconds after the ignition switch is to the ªONº position.
If the ªABSº light stays ªONº after the ignition switch is the
ªONº position, or comes ªONº and stays ªONº while
driving, the Anti-lock Brake System should be inspected
for a malfunction according to the diagnosis procedure.
Wheel Speed Sensor
It consists of a sensor and a rotor. The sensor is attached
to the knuckle on the front wheels and to the axle shaft
bearing holder on the rear wheels.
The rotor is press-fit in the axle shaft.The flux generated from electrodes magnetized by a
magnet in the sensor varies due to rotation of the rotor,
and the electromagnetic induction generates alternating
voltage in the coil. This voltage draws a ªsine curveº with
the frequency proportional to rotor speed and it allows
detection of wheel speed.
G-Sensor
The G-sensor installed inside the center console detects
the vehicle deceleration speed and sends a signal to the
EHCU. In 4WD operation, all four wheels may be
decelerated in almost the same phase, since all wheels
are connected mechanically.
This tendency is noticeable particularly on roads with low
friction coefficient, and the ABS control is adversely
affected.
The G-sensor judges whether the friction coefficient of
road surface is low or high, and changes the EHCU's
operating system to ensure ABS control.
Normal and Anti-lock Braking
Under normal driving conditions, the Anti-lock Brake
System functions the same as a standard power assisted
brake system. However, with the detection of wheel
lock-up, a slight bump or kick-back will be felt in the brake
pedal. This pedal ªbumpº will be followed by a series of
short pedal pulsations which occurs in rapid succession.
The brake pedal pulsation will continue until there is no
longer a need for the anti-lock function or until the vehicle
is stopped. A slight ticking or popping noise may be heard
during brake applications when the Anti-lock features is
being used.
When the Anti-lock feature is being used, the brake pedal
may rise even as the brakes are being applied. This is
also normal. Maintaining a constant force on the pedal
will provide the shortest stopping distance.
Brake Pedal Travel
Vehicles equipped with the Anti-lock Brake System may
be stopped by applying normal force to the brake pedal.
Although there is no need to push the pedal beyond the
point where it stops or holds the vehicle, by applying more
force the pedal will continue to travel toward the floor.
This extra brake pedal travel is normal.
Acronyms and Abbreviations
Several acronyms and abbreviations are commonly used
throughout this section:
ABS
Anti-lock Brake System
CKT
Circuit
DLC
Data Link Connector
EHCU
Electronic Hydraulic Control Unit
FL
Front Left