wheel ISUZU TROOPER 1995 Workshop Manual

5A4-22 4-WHEEL ANTI LOCK BRAKE SYSTEM (ABS)
(j): Pump Motor Relay Test
The pump motor operates when current flows through the pump motor relay coil (Fig. 5A4-9).
PUMP
MOTOR
~ II
....----
EBCM ~ .____
MOTOR RELAY
Fig. 5A4-9
Confirm the operation of the pump motor by its operating sound in the engine compartment.
TECH 1 Display Key Operation
Display 1 Is the pump motor working ? If so, press the YES key. If not, press the NO
key. (The pump motor works for about 5 seconds.)
P.MOTOR RELAY
COMMANDED ON * If the YES key is pressed, the menu display will be returned.
OKAY ?
(YES/NO)
If the NO key was pressed above
Display 2
A test failure.
The pump motor has mechanical trouble.
P.MOTOR RELAY
TEST FAILED * If the YES key is pressed, the menu display will be returned.
(YES)
If the YES or NO key was not pressed within 5 sec. on Display 1 above
Display 3
Did the pump motor work normally?
If so, press the YES key. If not, press the NO key.
P.MOTOR RELAY
OKAY ? * YES key c:::> Menu display
(YES/NO) *No key c:::>Display 2
•

4-WHEEL ANTILOCK BRAKE SYSTEM (ABS) 5A4-23
BRAKE
SYSTEM TEST (®, @, and @)
When conducting these tests, jack up the vehicle. Be sure to confirm that the brakes work normally.
Place transmission
in Neutral.
\V CAUTION: When testing the valves successively, leave time intervals of 10min. or more between tests so as to
protect the valves.
The operating conditions
of solenoid valve and resulting brake effect change during the test:
Test
Steps
1) Confirmation of no brake effect (Can the wheel(s) be turned by hand when the brake pedal is
released?).
2) Confirmation of brake effect (Can the wheel(s) be locked when the brake pedal is depressed?)
3) Brake oil pressure is reduced and held at that level.
4) Can the wheel(s) be turned by hand?
5) Solenoid valve is released so that brake pedal pressure reaches brake. Is the wheel(s) locked?
(2) (5)
I
(3)
(1) (4) I
I
..,. ;.,.. lncrea~e ..,.1.,.. Reduce I Increase ... : ... 1 -Retam 1 -Retain I -Retain I I I
I I I
I I I
I I I
ON
Brake
pedal OFF
Reduce
r
Retain
I Solenoid valve
Pump
motor ~

5A4-24 4-WHEEL ANTILOCK BRAKE SYSTEM (ABS)
®: Front left wheel brake system test
TECH 1 Display
Key Operation Brake
pedal
BEFORE TEST RUN • Prior to the test, be sure to understand the entire OFF ON
SEE CHECKING procedure.
PROCEDURE • To go to the next step, press the YES key.
(YES)
FL SOL. VALVE Can the wheel be turned by hand?
NORMAL FUNCTION If so, press the YES key. Of not, press the NO key. (lfthe NO
WHEEL TURNABLE ? key is pressed, Diaplay 1 will be returned.)
(YES/NO)
FL SOL. VALVE Depress the brake pedal. Hold it down through the rest of
NORMAL FUNCTION this test.
DEPRESS AND HOLD
BRAKE PEDAL !
FL SOL. VALVE Is the wheel locked ?
NORMAL FUNCTION If so, press the YES key. If not, press the NO key. (If the NO
WHEEL BLOCKED ? key is pressed, Display 1 will be returned.)
(YES/NO)
FL SOL. VALVE The TECH 1 commands the EBCM to reduce hydraulic
RELEASE FUNCTION pressure and activate the pump motor. Display
p. MOTOR RELAY automatically goes to next display after a few seconds.
Brake pressure has been reduced. Can the wheel be turned
FL SOL. VALVE by hand ? If so, press the YES key. If not, press the NO key.
RELEASE FUNCTION (If the NO key is pressed, Display 2 will be returned.)
WHEEL TURNABLE ? Note:
(YES/NO) To protect the valve, press the YES or NO key within 10
seconds.
FL SOL. VALVE With the solenoid valve released, brake pedal pressure is
RELEASE FUNCTION allowed to reach the brake.
WHEEL BLOCKED ? Is the wheel locked ? If so, press the YES key. If not, press
(YES/NO) the NO key. (If the NO key is pressed, Display 2 will be
returned.)
(Test is over.)
•

4-WHEEL ANTILOCK BRAKE SYSTEM (ABS) 5A4-25
TECH 1 Display Key Operation
Display 1 There is some problem in the normal hydraulic/mechanical brake system
(not
ABS problem).
FL SOL. VALVE Check the brake piping system.
NORMAL FUNCTION If the YES is pressed, the Menu Display will be returned.
TEST FAILED !
(YES)
Display 2 It is suspected that there is a mechanical abnormality in the related brake
piping.
Please check.
FL SOL. VALVE Press YES key, and MENU will return.
RELEASE FUNCTION
TEST FAILED !
C YES)

5A4-26 4-WHEEL ANTILOCK BRAKE SYSTEM (ABS)
@: Front right wheel brake system test
TECH 1 Display
Key Operation Brake pedal
BEFORE TEST RUN • Prior to the test, be sure to understand the entire OFF ON
SEE CHECKING procedure.
PROCEDURE • To go to the next step, press the YES key.
(YES)
FR SOL. VALVE Can the wheel be turned by hand ?
NORMAL FUNCTION If so, press the YES key. Of not, press the NO key. (If the NO
WHEEL TURNABLE ? key is pressed, Diaplay 1 will be returned.)
(YES/NO)
FR SOL. VALVE Depress the brake pedal. Hold it down through the rest of
NORMAL FUNCTION this test.
DEPRESS AND HOLD
BRAKE PEDAL !
FR SOL. VALVE Is the wheel locked ?
NORMAL FUNCTION If so, press the YES key. If not, press the NO key. (If the NO
WHEEL BLOCKED ? key is pressed, Display 1 will be returned.)
(YES/NO)
FR SOL. VALVE The TECH 1 commands the EBCM to reduce hydraulic
RELEASE FUNCTION pressure and activate the pump motor. Display
P. MOTOR RELAY automatically goes to next display after a few seconds.
Brake pressure has been reduced.
Can the wheel be turned
FR SOL. VALVE by hand? If so, press the YES key. If not, press the NO key.
RELEASE FUNCTION (If the NO key is pressed, Display 2 will be returned.)
WHEEL TURNABLE ? Note:
(YES/NO) To protect the valve, press the YES or NO key within 10
seconds.
FR SOL. VALVE With the solenoid valve released, brake pedal pressure is
RELEASE FUNCTION allowed to reach the brake.
WHEEL BLOCKED ? Is the wheel locked? If so, press the YES key. If not, press
(YES/NO) the NO key. (If the NO key is pressed, Display 2 will be
returned.)
(Test is over.)
•

4-WHEEL ANTI LOCK BRAKE SYSTEM (ABS) 5A4-27
TECH 1 Display Key Operation
Display 1 There
is some problem in the normal hydraulic/mechanical brake system
(not
ABS problem).
FR SOL. VALVE Check the brake piping system.
NORMAL FUNCTION If the YES is pressed, the Menu Display will be returned.
TEST FAILED
!
(YES)
Display 2 It is suspected that there is a mechanical abnormality in the related brake
piping. Please check.
FR SOL. VALVE Press YES key, and MENU will return.
RELEASE FUNCTION
TEST FAILED
!
(YES)

5A4-28 4-WHEEL ANTILOCK BRAKE SYSTEM (ABS)
@: Rear wheel brake system test
TECH 1 Display
Key Operation Brake
pedal
BEFORE TEST RUN • Prior to the test, be sure to understand the entire OFF ON
SEE CHECKING procedure.
PROCEDURE • To go to the next step, press the YES key.
(YES)
REAR SOL. VALVE Can the wheel be turned by hand ?
NORMAL FUNCTION If so, press the YES key. Of not, press the NO key. (If the NO
WHEEL TURNABLE ? key is pressed, Diaplay 1 will be returned.)
(YES/NO)
REAR SOL. VALVE Depress the brake pedal. Hold it down through the rest of
NORMAL FUNCTION this test.
DEPRESS AND HOLD
BRAKE PEDAL !
REAR SOL. VALVE Is the wheel locked ?
NORMAL FUNCTION If so, press the YES key. If not, press the NO key. Of the NO
WHEEL BLOCKED ? key is pressed, Display 1 will be returned.)
(YES/NO)
REAR SOL. VALVE The TECH 1 commands the EBCM to reduce hydraulic
RELEASE FUNCTION pressure and activate the pump motor. Display
P. MOTOR RELAY automatically goes to next display after a few seconds.
Brake pressure has been reduced. Can
the wheel be turned
REAR SOL. VALVE by hand ? If so, press the YES key. If not, press the NO key.
RELEASE FUNCTION (If the NO key is pressed, Display 2 will be returned.)
WHEEL TURNABLE ? Note:
(YES/NO) To protect the valve, press the YES or NO key within 10
seconds.
REAR SOL. VALVE With the solenoid valve released, brake pedal pressure is
RELEASE FUNCTION allowed to reach the brake.
WHEEL BLOCKED ? Is the wheel locked ? If so, press the YES key. If not, press
(YES/NO) the NO key. (If the NO key is pressed, Display 2 will be
returned.)
(Test is over.)
•

4-WHEEL ANTILOCK BRAKE SYSTEM (ABS) 5A4-29
TECH 1 Display
Key Operation
Display 1
There is some
problem in the normal hydraulic/mechanical brake system
(not
ABS problem).
REAR SOL. VALVE Check the brake piping system.
NORMAL FUNCTION lfthe YES is pressed, the Menu Display will be returned.
TEST FAILED !
(YES)
Display 2 It is suspected that there is a mechanical abnormality in the related brake
piping. Please check.
REAR SOL. VALVE Press YES key, and MENU will return.
RELEASE FUNCTION
TEST FAILED !
(YES)

5A4-30 4-WHEEL ANTILOCK BRAKE SYSTEM (ABS)
@: ABS
warning light test
In this test, light is actuated to make sure of its function (Fig. 5A4-10).
Fig. 5A4-10
TECH 1 Display
Key Operation
Is the light blinking ? ABS W/L * BLINK If so, press the YES key. If not, press the NO key.
OKAY ?
(YES/NO)
If
fault exists and the NO key is pressed
A test failure.
TEST FAILED Check ABS W/L wiring and
fuses.
(YES)
i _______________________________________________________________________ \
! •

4-WHEEL ANTILOCK BRAKE SYSTEM (ABS) 5A4-31
MODE F6: WHEEL SENSORS
When conducting the wheel sensor test, note the following:
1) Accelerate vehicle only slightly above 20 km/h (12 mph).
2) When this speed is attained, put transmission into neutral and allow vehicle to coast to a halt. (Parking
brake may be engaged slightly.)
3) When vehicle is at a standstill, actuate either foot brake or parking brake.
When the
wheel speed sensor test is being performed, the output or speed value of all four sensors is
monitored
by TECH 1. When the output of wheel sensors becomes too low to convert into speed value, the
last known vehicle speed is displayed and the values are fixed. If wheel sensors are normal, it is at the
vehicle speed
of 5 km/h (3 mph) or less that their output is lost. Therefore, if all the fixed speed values are
less than 5 km/h (3 mph), the wheel sensors are normal. If one or more of the four speed values is more
than 5 km/h
(3 mph), it suggests that the following abnormalities have occurred to the sensor(s):
1. Excess gap between the sensor and sensor rotor.
2. Broken or damaged sensor rotor teeth.
3. Momentary open in sensor harness.