1995 ISUZU TROOPER Workshop Manual

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)