light ISUZU AXIOM 2002 Service Manual PDF

5A±39
BRAKE CONTROL SYSTEM
Chart B-1 With the key in the ON position (Before starting the engine). Warning light (W/L)
is not activated.
StepActionYe sNo
1Is W/L fuse disconnected?Replace fuse.
Go to
Step 5Go to Step 2
2Is W/L burnt out?Replace W/L
bulb.
Go to
Step 5Go to Step 3
31. Turn the key off.
2. Disconnect coil integrated module connector (C-6).
3. Turn the key ON.
Is the check voltage between coil integrated module connector
(C-6) terminals 6 and 7 the battery voltage?
Go to Step 4
Repair harness
and connector.
Go to
Step 5
4Is there the continuity between coil integrated module connector
(C-6) terminals, 1 and 7 and body ground.Check harness
for suspected
disconnection
No fault found:
Replace EHCU.
Go to
Step 5
Repair harness
and connector.
Go to
Step 5
5Reconnect all components, ensure all components are properly
mounted.
Was this step finished?Repeat the ªBasic
diagnostic flow
chartº
Go to Step 5
Chart B-2 CPU Error (DTC 14 (Flash out) / C0271, C0272, C0273, C0284 (Serial
communications))
StepActionYe sNo
11. Turn the key off.
2. Disconnected coil integrated module connector.
3. Inspect coil integrated module ground.
Is there the continuity between the coil integrated module
connector terminals, 2 (C-5) and 7 (C-6) and body ground?
Go to Step 2
Repair the body
ground harness.
Go to
Step 3
21. Turn the key off, connect the coil integrated module connector.
2. Erase the trouble code.
3. Turn Ignition off, then on, to perform system self-check.
4. If warning light remains on, display trouble codes once again.
Is the trouble code the DTC 14 (Flash out) / C0271, C0272,
C0273, C0284 (Serial communications)?
Replace EHCU.
Go to
Step 3
Inspect in
accordance with
the DTC
displayed.
31. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the ªBasic
diagnostic flow
chartº
Go to Step 3

5A±41
BRAKE CONTROL SYSTEM
Chart B-6 G-Sensor Output Failure (DTC 21 (Flash out) / C0276 (Serial communications))
StepActionYe sNo
11. Turn the key off.
2. Replace EHCU.
3. Reconnect all components, ensure all components are
properly mounted.
Was this step finished?
Repeat the ªBasic
diagnostic flow
chartº
Go to Step 1
Chart B-7 Brake Switch Failure (DTC 22 (Flash out) / C0281 (Serial communications))
StepActionYe sNo
1Is the stop light actuated when the brake pedal is depressed?Go to Step 2Go to Step 4
21. Turn the key off.
2. Disconnected coil integrated module connector.
Is the check voltage between coil integrated module connector
(C-6) terminals 13 to 7 when brake pedal is depressed the battery
voltage?
Go to Step 3
Harness between
brake SW and
coil integrated
module is faulty.
Go to
Step 6
3Is the check that pins C-5 connector 2, and C-6 connector 7 have
good ground?Check harness /
connector for
disconnection
Fault found:
Repair, and
perform system
self-check.
No fault found:
replace EHCU.
Go to
Step 6
Repair.
Go to
Step 6
4Is stop light fuse normal?
Go to Step 5
Replace.
Go to
Step 6
5Is brake SW normal?Abnormal
harness in stop
light circuit.
Repair the
harness.
Go to
Step 6
Replace.
Go to
Step 6
61. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the ªBasic
diagnostic flow
chartº
Go to Step 6

5A±48BRAKE CONTROL SYSTEM
Chart B-20 FL Speed Sensor Missing Signal (DTC 61 (Flash out) / C0226, C0227 (Serial
communications))
StepActionYe sNo
11. Turn the key off.
2. Disconnect coil integrated module connector.
3. Measure the FL speed sensor resistance between coil
integrated module connector (C-6) terminals 2 and 10.
Is the resistance between 2.0k and 2.8k ohms?
Go to Step 2Go to Step 3
2Is there play sensor/sensor rotor?Repair.
Go to
Step 6Go to Step 4
3Measure the FL speed sensor resistance at the sensor connector.
Is the resistance between 2.0k and 2.8k ohms?Repair harness
abnormality
between sensors
and coil
integrated
module.
Go to
Step 6
Replace sensor.
Go to
Step 6
4Damage and powdered iron sticking to sensor/sensor ring?Repair.
Go to
Step 6Go to Step 5
5Is sensor output normal? (Chart C-1-1 or TC-1)Check for faults
in harness
between speed
sensor and coil
integrated
module.
Fault found:
repair, and
perform system
self-check.
No fault found:
replace EHCU.
Go to
Step 6
Replace sensor.
Go to
Step 6
61. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the ªBasic
diagnostic flow
chartº
Go to Step 6
NOTE: Even after repairing the faulty part the warning
light (W/L) does not go out if the vehicle is at a stop. Turn
the ignition switch to the ON position and drive the vehicle
at 12 km/h (8 mph) or higher to make sure that the
warning light goes out.

5A±49
BRAKE CONTROL SYSTEM
Chart B-21 FR Speed Sensor Missing Signal (DTC 62 (Flash out) / C0222, C0223 (Serial
communications))
StepActionYe sNo
11. Turn the key off.
2. Disconnect coil integrated module connector.
3. Measure the FR speed sensor resistance between coil
integrated module connector (C-6) terminals 3 and 11.
Is the resistance between 2.0k and 2.8k ohms?
Go to Step 2Go to Step 3
2Is there play sensor/sensor rotor?Repair.
Go to
Step 6Go to Step 4
3Measure the FR speed sensor resistance at the sensor
connector.
Is the resistance between 2.0k and 2.8k ohms?Repair harness
abnormality
between sensors
and coil
integrated
module.
Go to
Step 6
Replace sensor.
Go to
Step 6
4Damage and powered iron sticking to sensor/sensor ring?Repair.
Go to
Step 6Go to Step 5
5Is sensor output normal? (Chart C-1-2 or TC-1)Check for faults
in harness
between speed
sensor and coil
integrated
module.
Fault found:
repair, and
perform system
self-check.
No fault found:
replace EHCU.
Go to
Step 6
Replace sensor.
Go to
Step 6
61. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the ªBasic
diagnostic flow
chartº
Go to Step 6
NOTE: Even after repairing the faulty part the warning
light (W/L) does not go out if the vehicle is at a stop. Turn
the ignition switch to the ON position and drive the vehicle
at 12 km/h (8 mph) or higher to make sure that the
warning light goes out.

5A±50BRAKE CONTROL SYSTEM
Chart B-22 Rear Speed Sensor Missing Signal (DTC 63 (Flash out) / C0236, C0237 (Serial
communications))
StepActionYe sNo
11. Turn the key off.
2. Disconnect coil integrated module connector.
3. Measure the Rear speed sensor resistance between coil
integrated module connector (C-6) terminals 4 and 12.
Is the resistance between 1.0k and 1.7k ohms?
Go to Step 2Go to Step 3
2Is there play sensor/sensor rotor?Repair.
Go to
Step 6Go to Step 4
3Measure the rear speed sensor resistance at the sensor
connector.
Is the resistance between 1.0k and 1.7k ohms?Repair harness
abnormality
between sensors
and coil
integrated
module.
Go to
Step 6
Replace sensor.
Go to
Step 6
4Damage and powered iron sticking to sensor/sensor ring?Repair.
Go to
Step 6Go to Step 5
5Is sensor output normal? (Chart C-1-3 or TC-1)Check for faults
in harness
between speed
sensor and coil
integrated
module.
Fault found:
repair, and
perform system
self-check.
No fault found:
replace EHCU.
Go to
Step 6
Replace sensor.
Go to
Step 6
61. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the ªBasic
diagnostic flow
chartº
Go to Step 6
NOTE: Even after repairing the faulty part the warning
light (W/L) does not go out if the vehicle is at a stop. Turn
the ignition switch to the ON position and drive the vehicle
at 12 km/h (8 mph) or higher to make sure that the
warning light goes out.

5A±51
BRAKE CONTROL SYSTEM
Chart B-23 Simultaneous Drop-out of Front Speed Sensor Signal (DTC 64 (Flash out) /
C0229 (Serial communications))
StepActionYe sNo
11. Turn the key off.
2. Disconnect coil integrated module connector.
3. Measure the FL speed sensor resistance between coil
integrated module connector (C-6) terminals 2 and 10.
Is the resistance between 2.0k and 2.8k ohms?
Go to Step 2Go to Step 3
2Measure the FR speed sensor resistance between coil integrated
module connector (C-6) terminals 3 and 11.
Is the resistance between 2.0k and 2.8 k ohms?
Go to Step 5Go to Step 4
3Measure the FL speed sensor resistance at the sensor connector.
Is the resistance between 2.0k and 2.8k ohms?Repair harness
abnormality
between sensors
and coil
integrated
module.
Go to
Step 2
Replace sensor.
Go to
Step 2
4Measure the FR speed sensor resistance at the sensor
connector.
Is the resistance between 2.0k and 2.8k ohms?Repair harness
abnormality
between sensors
and coil
integrated
module.
Go to
Step 5
Replace sensor.
Go to
Step 5
5Damage and powered iron sticking to sensor/sensor ring?Repair.
Go to
Step 6Go to Step 6
6Is there play sensor/sensor rotor?Repair.
Go to
Step 7Go to Step 7
7Is sensor output normal? (Chart C-1-1&C-1-2 or TC-1)Check for faults
in harness
between speed
sensor and coil
integrated
module.
Fault found:
repair, and
perform system
self-check.
No fault found:
replace EHCU.
Go to
Step 8
Replace sensor.
Go to
Step 8
81. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat ªBasic
diagnostic flow
chartº
Go to Step 8
NOTE: Even after repairing the faulty part the warning
light (W/L) does not go out if the vehicle is at a stop. Turn
the ignition switch to the ON position and drive the vehicle
at 12 km/h (8 mph) or higher to make sure that the
warning light goes out.

5A±52BRAKE CONTROL SYSTEM
Chart B-24 Wheel Speed Input Abnormality (DTC 65 (Flash out) / C0238 (Serial
communications))
StepActionYe sNo
1Using TECH 2?Go to Step 2Go to Step 3
21. Connect TECH 2.
2. Select Snap shot manual trigger.
3. With wheel speed data displayed, run the vehicle when speed
has arrived at 30 km/h (18 mph).
4. Check speed data on each wheel (refer to the criterion given
below). * 1
Is the abnormal sensor condition found?
Replace.
Go to
Step 8
Go to Step 3
All the sensors
should follow the
following
flowchart (without
using TECH 2).
3Is there play in sensor/sensor ring?Repair.
Go to
Step 8Go to Step 4
4Is there powdered iron sticking to sensor/sensor ring?Repair.
Go to
Step 8Go to Step 5
5Is there a broken tooth or indentation in sensor ring?Replace sensor
ring.
Go to
Step 8Go to Step 6
6Is there play in wheel bearing?Adjust or repair.
Go to
Step 8Go to Step 7
7Is the check wiring between sensor and coil integrated module
normal?
Replace EHCU.
Go to
Step 8
Repair, and
perform system
self-check.
Go to
Step 8
81. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat `Basic
diagnostic flow
chartº
Go to Step 8
Sensor Signal Abnormality Criteria using TECH 2
1. While driving, the speed of one or two wheels is 25%
or more higher or lower than that of the other wheels.
2. The speed of one or two wheels is 10 km/h (6 mph) or
more higher or lower than that of the other wheels.
3. During steady driving, wheel speed changes abruptly.
*1 The vehicle must run on a level paved road.
NOTE: Even after repairing the faulty part the warning
light (W/L) does not go out if the vehicle is at a stop.
Turn the ignition switch to the ON position and drive the
vehicle at 12 km/h (8 mph) or higher to make sure that the
warning light goes out.
It is important to verify that the correct tires are installed
on vehicle.

5A±53
BRAKE CONTROL SYSTEM
Unit Inspection Procedure
This section describes the following inspection
procedures referred to during
Symptom Diagnosis and
Diagnosis By ªABSº Warning Light Illumination Pattern
without TECH 2with TECH 2
Sensor Output InspectionChart C-1-1 to C-1-3Chart TC-1
Chart C-1-1 FL Sensor Output Inspection Procedure
StepActionYe sNo
11. Turn the key off.
2. Disconnect coil integrated module connector.
3. Jack up the vehicle with all four wheels off the ground.
Measure the AC voltage between coil integrated module
connector terminals while turning FL wheel at a speed of 1
RPS:
Is the voltage between coil integrated module connector (C-6)
terminals 2 and 10 less than 200 mV?
Go to Step 2
OK.
Go to
Step 3
21. Disconnect the wheel speed sensor.
2. Measure resistance between the wheel speed sensor
connector terminals 1 and 2.
Is the check between connector (C-28) terminals 1 and 2 within
2.0k - 2.8k ohms?Connector is
faulty, or open or
short circuit of
harness between
wheel speed
sensor connector
and coil
integrated
module.
Inspect and
correct the
connector or
harness.
Go to
Step 3
Wheel speed
sensor is faulty.
Replace the
wheel speed
sensor.
Go to
Step 3
3Reconnect all components, ensure all components are properly
mounted.
Was this step finished?Repeat the ªBasic
diagnostic flow
chartº
Go to Step 3

5C±1 POWER±ASSISTED BRAKE SYSTEM
AXIOM (Vehicles Produced Before July/31/2001)
BRAKES
POWER-ASSISTED BRAKE SYSTEM
CONTENTS
Service Precaution 5C±2. . . . . . . . . . . . . . . . . . . . . .
General Description 5C±2. . . . . . . . . . . . . . . . . . . . .
Diagnosis 5C±6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Diagnosis 5C±7. . . . . . . . . . . . . . . . . . . . . . .
Hydraulic Brakes 5C±10. . . . . . . . . . . . . . . . . . . . . . . .
Filling Master Cylinder Reservoir 5C±10. . . . . . . .
Deterioration of Brake Fluid 5C±10. . . . . . . . . . . . .
Leakage of Brake Fluid 5C±10. . . . . . . . . . . . . . . . .
Bleeding Brake Hydraulic System 5C±10. . . . . . . .
Flushing Brake Hydraulic System 5C±11. . . . . . . .
Brake Pipes and Hoses 5C±11. . . . . . . . . . . . . . . .
Brake Hose Inspection 5C±11. . . . . . . . . . . . . . . . .
Front Caliper Brake Hose 5C±12. . . . . . . . . . . . . . . .
Front Caliper Brake Hose and Associated
Parts 5C±12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 5C±12. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 5C±12. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Axle Brake Hose 5C±13. . . . . . . . . . . . . . . . . . .
Rear Axle Brake Hose and Associated
Parts 5C±13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 5C±13. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 5C±13. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake Pipe 5C±14. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 5C±14. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 5C±14. . . . . . . . . . . . . . . . . . . . . . . . . . . .
P & B (Proportioning and Bypass) Valve 5C±15. . . .
P & B (Proportioning and Bypass) Valve
Sectional View 5C±15. . . . . . . . . . . . . . . . . . . . . . . .
Removal 5C±15. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 5C±15. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main Data and Specifications 5C±16. . . . . . . . . . . . .
Brake Pedal 5C±17. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking Pedal Height 5C±17. . . . . . . . . . . . . . . . .
Checking Pedal Travel 5C±17. . . . . . . . . . . . . . . . .
Brake Pedal and Associated Parts 5C±18. . . . . . .
Removal 5C±18. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 5C±18. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stoplight Switch 5C±19. . . . . . . . . . . . . . . . . . . . . . . . .
Parts Location 5C±19. . . . . . . . . . . . . . . . . . . . . . . .
Removal 5C±19. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 5C±19. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main Data and Specifications 5C±20. . . . . . . . . . . . .
Fluid Reservoir Tank 5C±21. . . . . . . . . . . . . . . . . . . . .
Fluid Reservoir Tank and Associated Parts 5C±21Removal 5C±21. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 5C±21. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Master Cylinder Assembly 5C±22. . . . . . . . . . . . . . . .
Master Cylinder Assembly and Associated
Parts 5C±22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 5C±22. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 5C±22. . . . . . . . . . . . . . . . . .
Installation 5C±23. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main Data and Specifications 5C±24. . . . . . . . . . .
Special Tools 5C±24. . . . . . . . . . . . . . . . . . . . . . . . . .
Vacuum Booster Assembly 5C±25. . . . . . . . . . . . . . .
Vacuum Booster Assembly and Associated
Parts 5C±25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 5C±25. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 5C±26. . . . . . . . . . . . . . . . . .
Installation 5C±26. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exterior Components 5C±28. . . . . . . . . . . . . . . . . . . .
Exterior Components and Associated Parts 5C±28
Removal 5C±28. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 5C±29. . . . . . . . . . . . . . . . . .
Installation 5C±29. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vacuum Booster Overhaul 5C±29. . . . . . . . . . . . . . . .
Vacuum Booster 5C±29. . . . . . . . . . . . . . . . . . . . . . .
Main Data and Specifications 5C±30. . . . . . . . . . . . .
Special Tools 5C±31. . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Disc Brake Pads 5C±32. . . . . . . . . . . . . . . . . . .
Front Disc Brake Pads Inspection 5C±32. . . . . . . .
Front Disc Brake Pads and Associated
Parts 5C±32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 5C±33. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 5C±33. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Disc Brake Rotor 5C±35. . . . . . . . . . . . . . . . . . .
Inspection 5C±35. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing Brake Rotors 5C±35. . . . . . . . . . . . . . . .
Refinishing Brake Rotors 5C±35. . . . . . . . . . . . . . .
Front Disc Brake Caliper Assembly 5C±36. . . . . . . .
Front Disc Brake Caliper Assembly and
Associated Parts 5C±36. . . . . . . . . . . . . . . . . . . . . .
Removal 5C±37. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 5C±37. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Disc Brake Caliper 5C±39. . . . . . . . . . . . . . . . .
Front Disc Brake Caliper Disassembled
View 5C±39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly 5C±39. . . . . . . . . . . . . . . . . . . . . . . . . .

5C±6
POWER±ASSISTED BRAKE SYSTEM
Diagnosis
Road Testing The Brakes
Brake Test
Brakes should be tested on a dry, clean, reasonably
smooth and level roadway. A true test of brake
performance cannot be made if the roadway is wet,
greasy or covered with loose dirt where all tires do not grip
the road equally. Testing will also be adversely affected if
the roadway is crowned so as to throw the weight of the
vehicle toward wheels on one side or if the roadway is so
rough that wheels tend to bounce. Test the brakes at
different vehicle speeds with both light and heavy pedal
pressure; however, avoid locking the wheels and sliding
the tires. Braking without locking the tires will stop the
vehicle in less distance than braking to a skid (which has
no brake efficiency). More tire to road friction is present
while braking without locking the tires than braking to a
skid.
The standard brake system is designed and balanced to
avoid locking the wheels except at very high deceleration
levels.
It is designed this way because the shortest stopping
distance and best control is achieved without brake
lock±up.
Because of high deceleration capability, a firmer pedal
may be felt at higher deceleration levels.
External Conditions That Affect Brake Performance
1. Tires: Tires having unequal contact and grip on the
road will cause unequal braking. Tires must be
equally inflated, identical in size, and the thread
pattern of right and left tires must be approximately
equal.
2. Vehicle Loading: A heavily loaded vehicle requires
more braking effort.
3. Wheel Alignment: Misalignment of the wheels,
particularly in regard to excessive camber and caster,
will cause the brakes to pull to one side.
Brake Fluid Leaks
With engine running at idle and the transmission in
ªNeutralº, depress the brake pedal and hold a constant
foot pressure on the pedal. If pedal gradually falls away
with the constant pressure, the hydraulic system may be
leaking.
Check the master cylinder fluid level. While a slight drop in
the reservoir level will result from normal lining wear, an
abnormally low level in reservoir indicates a leak in the
system. The hydraulic system may be leaking internally
as well as externally. Refer to
Master Cylinder Inspection.
Also, the system may appear to pass this test but still
have slight leakage. If fluid level is normal, check the
vacuum booster push rod length. If an incorrect length
push rod is found, adjust or replace the push rod. Check
the brake pedal travel and the parking brake adjustment.
When checking the fluid level, the master cylinder fluid
level may be lower than the ªMAXº mark if the front and
rear linings are worn. This is normal.
Warning Light Operation
When the ignition switch is in the START position, the
ªBRAKEº warning light should turn on and go off when the
ignition switch returns to the ON position.
The following conditions will activate the ªBRAKEº light:
1. Parking brake applied. The light should be on
whenever the parking brake is applied and the ignition
switch is on.
2. Low fluid level. A low fluid level in the master cylinder
will turn the ªBRAKEº light on.
3. During engine cranking the ªBRAKEº light should
remain on. This notifies the driver that the warning
circuit is operating properly.