stop start ISUZU AXIOM 2002 Service Owner's Manual

4B2±97
DRIVE LINE CONTROL SYSTEM (TOD)
StepActionYe sNo
1Start the engine.
When the TOD switch is selected to the TOD position, is 0V
observed between terminals 42 and 47?
Go to Step 2Go to Step 6
21. The car stops, the AT selector is N position, and the brake is
applied.
When the TOD switch is selected to the 4L position, is 0V
observed between terminals 42 and 47?
Go to Step 3Go to Step 6
31. The car stops, the AT selector is N position, and the brake is
applied.
2. Select the TOD switch to the 2H position.
Is 5V observed between terminals 42 and 47?
Go to Step 4Go to Sep 6
4Is 12V observed between terminals 7 and 47?
Go to Step 5
Replace the
ECU.
Go to
Step 10
5Is 12V observed between terminals 19 and 47?The phenomenon
is not
reproduced.
Refer to
ªTroubles
intermittently
observedº.
The ECU has
failed.Replace
the ECU.
Go to
Step 10
61. The car stops, the AT selector is N position, and the brake is
applied.
When the TOD switch is selected to the 2H position, is the battery
voltage observed between terminals 23 and 47?
Go to Step 7Go to Step 9
71. The car stops, the AT selector is N position, and the brake is
applied.
When the TOD switch is selected to the TOD position, is 0V
observed between terminals 23 and 47?
Go to Step 8Go to Step 9
81. The car stops, the AT selector is N position, and the brake is
applied.
When the TOD switch is selected to the 4L position, is 0V
observed between terminals 23 and 47?Repair the circuit
or check the
ªFront Axle
Disconnectº.
(Refer to
section
4B
)
Go to
Step 10Go to Step 9
9Is any of the trouble codes 28 (P1760), 32 (P1761) and 33
(P1762) recorded?Examine the
trouble based on
ªDiagnosis from
Trouble Codesº.The ECU has
failed. Replace
the ECU.
Go to
Step 10
10Check that all the parts are mounted.
Is this step complete?
Verify the repair.Go to Step 10

4B2±113
DRIVE LINE CONTROL SYSTEM (TOD)
StepActionYe sNo
11. Turn on the starter switch.
Is any of the trouble codes 41 (P1741), 42 (P1773), 43 (P1743)
and 55 (P1755) recorded?Examine the
trouble based on
ªDiagnosis from
Trouble Codesº.
Go to Step 2
2Is any of the trouble codes 13 (P1735), 14 (P1731), 15 (P1736),
16 (P1737), 24 (P1733), and 27 (P1738) recorded?Examine the
trouble based on
ªDiagnosis from
Trouble Codesº.
Go to Step 3
3Is the trouble code 17 (P1774) recorded?Examine the
trouble based on
ªDiagnosis from
Trouble Codesº.
Go to Step 4
41. Turn on the starter switch.
2. The car stops, engine speed is less than 1500 rpm, the AT
selector is N position, and select the TOD switch to the 4L
position.
Do the front lamp and rear lamp in the indicator blink?
Go to Step 5
Examine the
trouble based on
ªTrouble
Diagnosis
Depending on the
Status of TOD
Indicatorº.
51. Step on the brake pedal.
Is the transfer changed to the 4L mode?The phenomenon
is not
reproduced.
Refer to
ªTrouble
intermittently
observedº.
Go to Step 6
6When the vehicle is moved forth and back, is the transfer changed
to the 4L mode?The phenomenon
is not
reproduced.
Refer to
ªTrouble
intermittently
observedº.
Go to Step 7
7Does the continuity corresponding to the encoder position
between the terminals comply with the 4L position in the following
table (continuity)?Examine the
trouble based on
ªTrouble
diagnosis
Depending on
The Status of
TOD Indicatorº.
Go to Step 8
81. Step on the brake pedal.
Is the battery voltage observed between the terminal 37 and 47?
Go to Step 10Go to Step 9
91. Turn off the starter switch.
2. Disconnect the ECU connector (C±37) and the brake switch
connector (I±31).
Is there the continuity between the connector terminal (C±37) 15
and (I±31) 4?The brake switch
is abnormal.
Repair or replace
the brake switch.
Go to
Step 13
Repair the
harness.
Go to
Step 13
101. Select the AT selector to the N position.
Is the voltage between the terminals ranged within the following
table (voltage)?
Go to Step 12Go to Step 11
111. Turn off the starter switch.
2. Disconnect the ECU connector (C±37).
3. Disconnect the AT mode switch connector (E±41).
Is there the continuity between the following connector terminals?
(C±37)6 and (E±41)8 (C±37)19 and (E±41)7 (C±37)5 and
(E±41)6
Repair or replace
the AT mode
switch.
Go to
Step 13
Repair the circuit
which has no
continuity.
Go to
Step 13

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±116
StepActionYe sNo
11. Turn on the starter switch.
Is any of the trouble codes 41 (P1741), 42 (P1773), 43 (P1743)
and 55 (P1755) recorded?Examine the
trouble based on
ªDiagnosis from
Trouble Codesº.
Go to Step 2
2Is any of the trouble codes 13 (P1735), 14 (P1731), 15 (P1736),
16 (P1737), 24 (P1733), and 27 (P1738) recorded?Examine the
trouble based on
ªDiagnosis from
Trouble Codesº.
Go to Step 3
3Is the trouble code 17 (P1774) recorded?Examine the
trouble based on
ªDiagnosis from
Trouble Codesº.
Go to Step 4
41. Turn on the starter switch.
2. The car stops, engine speed is less than 1500 rpm, the AT
selector is N position, and select the TOD switch to the TOD
position.
Do the front, rear, and AUTO lamps in the indicator blink?
Go to Step 5
Examine the
trouble based on
ªTrouble
Diagnosis
Depending on the
Status of TOD
Indicatorº.
51. Step on the brake pedal.
Is the transfer changed to the TOD mode?The phenomenon
is not
reproduced.
Refer to
ªTrouble
intermittently
observedº.
Go to Step 6
6When the vehicle is moved forth and back, is the transfer changed
to the TOD mode?The phenomenon
is not
reproduced.
Refer to
ªTrouble
intermittently
observedº.
Go to Step 7
7Is the continuity corresponding to the encoder position between
the terminals ranged within the any case (case 1, 2 and 3) of TOD
position in the following table (continuity)?Examine the
trouble based on
ªTrouble
diagnosis
Depending on
The Status of
TOD Indicatorº.
Go to Step 8
81. Step on the brake pedal.
Is the battery voltage observed between the terminal 37 and 47?
Go to Step 10Go to Step 9
91. Turn off the starter switch.
2. Disconnect the ECU connector (C±37) and the brake switch
connector (I±31).
Is there the continuity between the connector terminal (C±37) 15
and (I±31) 4?The brake switch
is abnormal.
Repair or replace
the brake switch.
Go to
Step 13
Repair the
harness.
Go to
Step 13
101. Select the AT selector to the N position.
Is the voltage between the terminals ranged within the following
table (voltage)?
Go to Step 12Go to Step 11
111. Turn off the starter switch.
2. Disconnect the ECU connector (C±37) and brake switch
connector (I±31).
3. Disconnect the AT mode switch connector (E±41).
Is there the continuity between the following connector terminals?
(C±37)6 and (E±41)8 (C±37)19 and (E±41)7 (C±37)5 and
(E±41)6
Repair or replace
the AT mode
switch.
Go to
Step 13
Repair the circuit
which has no
continuity.
Go to
Step 13

5A±11
BRAKE CONTROL SYSTEM
Acronyms and Abbreviations
Several acronyms and abbreviations are commonly used
throughout this section:
ABS
Anti-lock Brake System
CIM
Coil Integrated Module
CKT
Circuit
DLC
Data Link Connector
EHCU
Electronic Hydraulic Control Unit
FL
Front Left
FR
Front Right
GEN
Generator
H/U
Hydraulic Unit
MV
Millivolts
RR
Rear
RPS
Revolution per Second
VDC
DC Volts
VA C
AC Volts
W/L
Warning Light
WSS
Wheel Speed Sensor
General Diagnosis
General Information
ABS troubles can be classified into two types, those
which can be detected by the ABS warning light and those
which can be detected as a vehicle abnormality by the
driver.
In either case, locate the fault in accordance with the
ªBASIC DIAGNOSTIC FLOWCHARTº and repair.
Please refer to
Section 5C for the diagnosis of
mechanical troubles such as brake noise, brake judder
(brake pedal or vehicle vibration felt when braking),
uneven braking, and parking brake trouble.
ABS Service Precautions
Required Tools and Items:

Box Wrench

Brake Fluid

Special ToolSome diagnosis procedures in this section require the
installation of a special tool.
J-39200 High Impedance Multimeter
When circuit measurements are requested, use a circuit
tester with high impedance.
Computer System Service Precautions
The Anti-lock Brake System interfaces directly with the
Electronic Hydraulic Control Unit (EHCU) which is a
control computer that is similar in some regards to the
Powertrain Control Module. These modules are designed
to withstand normal current draws associated with
vehicle operation. However, care must be taken to avoid
overloading any of the EHCU circuits. In testing for opens
or shorts, do not ground or apply voltage to any of the
circuits unless instructed to do so by the appropriate
diagnostic procedure. These circuits should only be
tested with a high impedance multimeter (J-39200) or
special tools as described in this section. Power should
never be removed or applied to any control module with
the ignition in the ªONº position.
Before removing or connecting battery cables, fuses or
connectors, always turn the ignition switch to the ªOFFº
position.
General Service Precautions
The following are general precautions which should be
observed when servicing and diagnosing the Anti-lock
Brake System and/or other vehicle systems. Failure to
observe these precautions may result in Anti-lock Brake
System damage.

If welding work is to be performed on the vehicle using
an electric arc welder, the EHCU and valve block
connectors should be disconnected before the
welding operation begins.

The EHCU and valve block connectors should never
be connected or disconnected with the ignition ªONº .

If only the rear wheels are rotated using jacks or drum
tester, the system will diagnose a speed sensor
malfunction and the ªABSº warning light will
illuminate. But actually no trouble exists. After
inspection stop the engine once and re-start it, then
make sure that the ªABSº warning light does not
illuminate.
If the battery has been discharged
The engine may stall if the battery has been completely
discharged and the engine is started via jumper cables.
This is because the Anti-lock Brake System (ABS)
requires a large quantity of electricity. In this case, wait
until the battery is recharged, or set the ABS to a
non-operative state by removing the fuse for the ABS
(50A). After the battery has been recharged, stop the
engine and install the ABS fuse. Start the engine again,
and confirm that the ABS warning light does not light.
Note on Intermittents
As with virtually any electronic system, it is difficult to
identify an intermittent failure. In such a case duplicating
the system malfunction during a test drive or a good
description of vehicle behavior from the customer may be
helpful in locating a ªmost likelyº failed component or

5A±12BRAKE CONTROL SYSTEM
circuit. The symptom diagnosis chart may also be useful
in isolating the failure. Most intermittent problems are
caused by faulty electrical connections or wiring. When
an intermittent failure is encountered, check suspected
circuits for damage:

Suspected harness damage.

Poor mating of connector halves or terminals not fully
seated in the connector body (backed out).

Improperly formed or damaged terminals.
Test Driving ABS Complaint Vehicles
In case of an intermittent ABS lamp illumination, see
ªDiagnosis by ABS Warning Light illumination Patternº or
go to 5A±37. In some cases, the vehicle may need to be
test driven by following the test procedure below.
1. Start the engine and make sure that the ªABSº W/L
goes OFF. If the W/L remains ON, it means that the
Diagnostic Trouble Code (DTC) is stored. Therefore,
read the code and locate the fault.
NOTE: The DTC cannot be cleared if the vehicle speed
does not exceed 12 km/h (8 mph) at DTC, even though
the repair operation is completed.
2. Start the vehicle and accelerate to about 30 km/h (19
mph) or more.
3. Slowly brake and stop the vehicle completely.
4. Then restart the vehicle and accelerate to about 40
km/h (25 mph) or more.
5. Brake at a time so as to actuate the ABS and stop the
vehicle.
6. Be cautious of abnormality during the test. If the W/L
is actuated while driving, read the DTC and locate the
fault.
7. If the abnormality is not reproduced by the test, make
best efforts to reproduce the situation reported by the
customer.
8. If the abnormality has been detected, repair in
accordance with the ªSYMPTOM DIAGNOSISº .
NOTE:

Be sure to give a test drive on a wide, even road with a
small traffic.

If an abnormality is detected, be sure to suspend the
test and start trouble diagnosis at once.
ªABSº Warning Light
When ABS trouble occurs to actuate ªABSº warning light,
the trouble code corresponding to the trouble is stored in
the EHCU. Only ordinary brake is available with ABS
being unactuated. Even when ªABSº warning light is
actuated, if the starter switch is set ON after setting it OFF
once, the EHCU checks up on the entire system and, if
there is no abnormality, judges ABS to work currently and
the warning light is lit normally even though the trouble
code is stored.
NOTE: Illumination of the ªABSº warning light indicates
that anti-lock braking is no longer available. Power
assisted braking without anti-lock control is still available.
Normal Operation
ªABSº Warning Light
When the ignition is first moved from ªOFFº to ªRUNº , the
amber ªABSº warning light will turn ªONº . The ªABSº
warning light will turn ªONº during engine starting and will
usually stay ªONº for approximately three seconds after
the ignition switch is returned to the ªONº position. The
warning light should remain ªOFFº at all other times.

5A±16BRAKE CONTROL SYSTEM
DATA LIST
The data displayed by DATA LIST are as follows:
Display
ContentOK/NG Criteria for Data
Front Left Wheel Speed
Front Right Wheel Speed
Rear Wheel Speedskm/h (MPH)
Start the vehicle and make sure of linear change in
each wheel speed.

Turn each wheel by hand and make sure that each
speed data change.
Warning LampON/OFF
To be OFF usually
ABS StateON/OFF
To be OFF usually
ABS RelayActive/Inactive
To be Active usually
4 Wheel DriveActive/Inactive
2WD: Inactive

4WD: Active
Brake SwitchActive/Inactive
Inactive (Released)

Active (Pressed)
Brake Fluid LevelNormal or not
To be Normal usually
Return PumpActive/Inactive
To be Inactive usually
DRP (Dynamic Rear
Proportioning)Active/Inactive
To be Inactive usually
Rear Dump Valve CommandedActive/Inactive
To be Inactive usually
Rear Dump Valve Feedback
Rear Isolation Valve
Commanded
Rear Isolation Valve Feedback
FL Dump Valve CommandedActive/Inactive
To be Inactive usually
FL Dump Valve Feedback
FL Isolation Valve Commanded
FL Isolation Valve Feedback
FR Dump Valve CommandedActive/Inactive
To be Inactive usually
FR Dump Valve Feedback
FR Isolation Valve
Commanded
FR Isolation Valve Feedback
G±SensorVoltage
2.50V when vehicle is stopped
Battery VoltageVoltage
Between 10±16.9V

5A±17
BRAKE CONTROL SYSTEM
ACTUATOR TEST
This mode is used to exercise the ABS actuators and
make sure they operate normally. Prior to the test, pay
attention to the cautions below. (When checking the
solenoid valve system, be sure to jack up the vehicle.)
CAUTION:

Before testing, be sure that the brakes work normally.

Make sure that the battery is fully charged.Conduct
the test by two persons (A TECH 2 operator and a
vehicle checker).

Be sure to start ACTUATOR TEST with the engine
stopped.

Before testing, make sure that electrical trouble, if
any, has been completely repaired. Conducting tests
of ABS solenoid with electrical circuit problem
remaining uncorrected could damage the control unit.
F05R200001

5A±37
BRAKE CONTROL SYSTEM
Diagnostic Trouble Codes (DTCs)
When the warning light in the meter remains ON, the
EHCU stores the fault identification and disables the
ABS.
How to display and erase DTCs:
NOTE:

DTCs can be displayed also by TECH 2. Use
ªDiagnostic Trouble Codesº mode.1. How to start DTC display:

Confirm that the vehicle has come to a complete
stop (with the wheels standing still) and that the
brake pedal is not depressed. (Unless these two
condition are satisfied, DTC display cannot be
started.)

With IGN OFF, connect #12 terminal with #4
terminal or # 5 terminal (GND) . Then turn IGN ON.
The DLC is located behind the driver side kick panel
350R200001

Keep #12 terminal connected with #4 terminal or # 5
terminal (GND) during DTC display. (If #12 terminal
is separated from #4 terminal or # 5 terminal (GND)
during display, display will stop.)
2. DTC display:

DTC is displayed by blinking warning light.

Double-digit display.

First, normal DTC 12 is displayed three times and
then any other DTCs are displayed three times. (If
no other DTCs have been stored, the display of DTC
12 will be repeated.)3. How to erase code:

Conduct brake switch ON/OFF operation 6 or more
times within 3 seconds of self-diagnosis startup.

The code cannot be erased if more than 3 seconds
have passed since self-diagnosis startup, or if
self-diagnosis has started with brake switched on
(brake pedaled).
B05RW005

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.

5C±17 POWER±ASSISTED BRAKE SYSTEM
Brake Pedal
Checking Pedal Height
The push rod serves as the brake pedal stopper when the
pedal is fully released. Brake pedal height adjustment
should be performed as follows:
Adjust Brake Pedal
310RY00004
1. Measure the brake pedal height after making sure the
pedal is fully returned by the pedal return spring.
Pedal height must be measured after starting the
engine and receiving it several times.
Pedal Free Play: 6-10 mm (0.23-0.39 in)
Pedal Free Play: 173-185 mm (6.81-7.28 in)
NOTE: Pedal free play must be measured after turning
off the engine and stepping on the brake pedal firmly five
times or more.
2. If the measured value is not within the above range,
adjust the brake pedal as follows:
a. Disconnect the stoplight switch connector.
b. Loosen the stoplight switch lock nut.
c. Rotate the stoplight switch so that it moves away
from the brake pedal.
d. Loosen the lock nut (1) on the push rod.
e. Adjust the brake pedal to the specified height by
rotating the push rod in the appropriate direction.
f. Tighten the lock nut to the specified torque.
Torque: 20 N´m (15 lb ft)
g. Adjust the stoplight switch (2) to the specified
clearance (between the switch housing and the
brake pedal) by rotating the switch housing.
Clearance: 0.5±1.0 mm (0.02±0.04 in)
310RY00005
NOTE: While adjusting the stoplight switch, make sure
that the threaded part of the stoplight switch does not
push the brake pedal.
h. Tighten the stoplight switch lock nut.
i. Connect the stoplight switch connector.
Checking Pedal Travel
310RY00004
1. Pedal height must be measured after starting the
engine and revving it several times to apply vacuum
to the vacuum booster fully.
NOTE: Pedal height must be 95 mm (3.7 in) or more
when about 50 kg (110.25 lb) of stepping force is applied.
2. If the measured value is lower than the above range,
air may still be present in the hydraulic system
Perform the bleeding procedure.