brake sensor ISUZU TROOPER 1995 Manual Online

8 -178 CHASSIS ELECTRICAL
ANTI-LOCK BRAKE SYSTEM (ABS)
GENERAL DESCRIPTION
The circuit consists of the starter switch, stoplight switch (vehicle w/o cruise control), brake switch (vehicle
with cruise control), hydraulic unit, electronic brake control module, wheel speed sensor, G sensor, ABS and
4WD indicator, 4WD switch and data link connector.
When the service brake is applied while in the running mode,
the EBCM (Electronic Brake Control Module)
judges
which wheel is about to lock by using the wheel rotation speed signals sent from the four ABS speed
sensors at the
front and rear wheels. And the brake fluid pressure applied to the four wheels is controlled by
a hydraulic unit to prevent the wheels from locking.
Based on the wheel rotation speed signals
input from the ABS sensor, the EBCM sends out signals to the
solenoid valve in the hydraulic unit
to increase, maintain or decrease the brake fluid pressure. The solenoid
valve uses this signal
to control the fluid pressure which is applied to the calipers of the disk brakes of the
front wheels. (The system also controls at the same time the fluid pressure applied to the rear wheels.)
• EBCM (Electronic brake control module)
The EBCM uses the signals sent from the speed sensor to control the operation of the hydraulic unit.
When any malfunction occurs in the ABS, the
EBCM activates the fail-safe fuction while turning on the
ABS warning light.
• Hydraulic unit
The hydraulic unit consists of the motor, plunger pump, solenoid valve, and fluid pressure control
valves. The exterior
of the unit has a relay box consisting of the motor relay and valve relay. Three
solenoid valves, the
two of which are provided at the front wheels and the one at the rear wheels, control
the fluid pressure
of these wheels.
• Speed sensor
The speed sensor consists of the sensor and the rotor. It sends the EBCM the AC voltage generated by
the rotation of the rotor as the vehicle speed signal. ~
• G-sensor
The G-sensor, installed inside the center console, sends out signals to the EBCM by detecting the
decelerating speed
of the vehicle.
• ABS warning light
The ABS warning light in the instrument panel, lights up when any malfunction occurs in the ABS. It also
lights up
with the starter key at the "ON" position, as a self-check.
Refer
to Section 5A4, "ANTI-LOCK BRAKE SYSTEM" for detail.
II

::!! (Q 00 I N N 00
(
EBCM
RR
ABS
SPEED
SENSOR
(RHI
RELAY:
UPSHIFT-2
C-33 C-34
(
(
STARTERSW RR
ABS
SPEED
SENSOR
ILHI
C-94 DATA
LINK
CONNECTOR
GSENSOR
FUSE
BOX
(C-3,
C-4,
C-10,
C-141
BRAKE
SW
(W/CRUISE
CONTROL)
STOPLIGHT
SW
IW/0
CRUISE
CONTROL)
FRT
ABS
SPEED
SENSOR
ILHI
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CHASSIS ELECTRICAL 8-185
REAR WHEEL ANTI-LOCK BRAKE SYSTEM (RWAL)
GENERAL DESCRIPTION
The circuit consists of the starter switch, stoplight switch (vehicle w/o cruise control), brake switch (vehicle
w/cruise control). RWAL controller, RWAL speed sensor, RWAL valve, brake differential switch, 4WD switch,
parking brake
SW, indicator light (RWAL, 4WD, BRAKE), and test connector.
In this system, when the service brake is applied the RWAL controller judges the wheel rotation difference
signals which have been sent from the RWAL speed sensor at the rear axle differential. The anti-lock valves
control
the brake fluid pressure which is applied to the rear wheels to prevent the wheels from locking.
When starting the engine, the RWAL indicator in the instrument panel lights up at the same time as the brake
indicator
to inform the driver that the system is operating normally. (The light goes off after two seconds.)
Refer
to Section 5A3, "RWAL (REAR WHEEL ANTI-LOCK BRAKE SYSTEM)" for detail.

8-192 CHASSIS ELECTRICAL
TRANSMISSION CONTROL MODULE (TCM)
GENERAL DESCRIPTION
The circuit consists of the starter switch, TCM, mode switch, brake switch, speed sensor, kick down switch,
Power and
Winter switches, Throttle Position (TP) sensor, Engine Control Module (ECM), barometer sensor,
adapter case, main case,
warning light (CHECK TRANS, NT OIL TEMP) and indicator light (WINTER DRIVE,
POWER DRIVE).
The TCM, based on the predetermined shifting characteristics and lockup operating valve, provides the
optimum shifting control to the varying vehicle running condition. The following input signals are sent to the
TCM: select lever position from the mode switch, running mode from the POWER & WINTER switches,
throttle opening from the TP sensor, vehicle speed from the vehicle speed sensor and engine speed from the
ECM are sent to the TCM. After receiving these signals, the TCM determines the vehicle running condition,
and
it sends output signals to each solenoid to control shifting.
When the
TCC solenoid is engaged, the lockup mechanism operates.
The shift
solenoid 2.3 and 1.2/3.4 selects the shift gear position.
The force
motor controls the line pressure to improve shifting.
Also, when the TCM detects an abnormal signal from the transmission or sensor, it will cause the "CHECK
TRANS"
light on the warning box to flash in order to inform the driver of the malfunction.
Refer to section 7 A "AUTOMATIC TRANSMISSION" for details.
•

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(
FRONT
CONSOLE
DIAGNOSIS
CONNECTOR
"~",
DATA
LINK
CONNECTOR,
·~
RELAY
& FUSE
BOX
(FL-1,
FL-2,
FL-3)
TPSENSOR H-42-
SPEED
SENSOR
ECM:
ENGINE
CONTROL
MODULE
ICM(CONT)
TCM:
TRANSMISSION
CONTROL
MODULE
TP
: THROTTLE
POSITION
ICM
: IGNITION
CONTROL
MODULE
~;
t I:;::==PI
v
/)
WARNING
BOX
' .
!I
/;;'
H-32
FUSE
BOX
(C-3,
C-4, C-8,
C-10,
C-14)
BRAKESW
KICKDOWNSW ACCELERATOR
PEDAL
BAROMETRIC
SENSOR
(
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8-288 CHASSIS ELECTRICAL
METER AND WARNING/INDICATOR LIGHT
GENERAL DESCRIPTION
The circuit consists of the starter switch, meter assembly, vehicle speed sensor, clutch switch, transmission
switch, lighting switch,
turn signal switch, thermo unit, oil pressure unit, Engine Control Module, fuel tank unit,
4WD
SW, oil pressure switch, parking brake switch, brake fluid switch, seat belt switch and illumination
controller.
The meter ASM contains the speedometer, tachometer, voltmeter, engine coolant temperature gauge, oil
pressure gauge, fuel gauge and warning/indicator lights.
The meter warning/indicator lights and
their bulb sockets are a unit, they are installed from the back of the
speedometer assembly.

::!!
(
(
PARKING
BRAKE
SW
PARKING
BRAKE
LEVER
VEHICLE
SPEED
SENSOR

4WD
INDICATOR
SW,

~
' '
/;~>
TRANSMISSION
3-4SW
IMJT)

"vf;/
RESISTOR;UPSHIFT
."­
RELAY;UPSHIFT-1
~":'""
RELAY
& FUSE
BOX-_
(FL-1
,FL-21 BA.
TTERY--.;:;4"~
H-41 H-42
-----;1-"'.,.,-~
THERMO
UNIT
FUEL
TANK
UNIT
(FUEL
TANK)
METERASM
~
16)
1 /
1
(
H-7
/'1'-J
? I n
H-8 H-9 H-25
H-26 C..15 BRAKE
FLUID
SW
(BRAKE
FLUID
TANK}
FUSE
BOX
IC-4,
C-10}
\CLUTCH
SW
(M/T)
CLUTCH
PEDAL
(Mm
(
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---------------~-~---
CRUISE CONTROL 9B-1
SECTION 98
CRUISE CONTROL
CONTENTS
General description ................................ .
Parts location .......................................... .
Circuit diagram ....................................... .
Diagnosis ................................................. .
On-vehicle service ................................. ..
Brake switch adjustment ................ ..
Clutch switch adjustment ................ .
Actuator
cable adjustment .............. .
Starter switch ................................... .
Cruise control main switch .............. .
GENERAL DESCRIPTION
98-1
9B-3
98-4
9B-7
98-28
9B-28
9B-28
9B-28
9B-28
9B-30 Cruise
control
switch
(combination switch) ........................ 98-31
Cruise control unit .......................... ... 9B-32
Pump
& actuator .................. .............. 9B-34
Brake switch ....................................... 9B-36
Clutch switch .............................. ....... 9B-36
Mode switch .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 9B-37
Vehicle speed sensor
(incorporated in speedometer) ......... 9B-38
Diode
.. .. .. .. .. .. . .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. . .. .. .. 9B-38
Cruise control main relay .................. 9B-39
The circuit consists of the starter switch, cruise control main switch, cruise control switch, cruise control unit,
pump &actuator, brake switch, clutch switch (M/T), mode switch (A/T), vehicle speed sensor (incorporated into
the speedometer) and indicator light.
The cruise control keeps
the vehicle running at a fixed speed until a signal canceling this fixed speed is received.
When the main switch "AUTO CRUISE" is turned on with the vehicle in the running mode, the battery voltage
is applied
to the control unit. When a signal from the control switch is input to the control unit while the vehicle
is in this state, the cruise control actuator is activated to operate the system .
.._, Also, while the system is operating, the "AUTO CRUISE" indicator light in the indicator box lights up.
1. SET /COAST SWITCH FUNCTION
1) SET function: When the SET/COAST switch
is pressed and released
with the main switch
on, the speed at
which the vehicle is running
at that moment is stored in the memory, and
the vehicle
automatically runs at the speed
stored.
2) COAST-DOWN function: When the SET/
COAST switch is kept on while the vehicle in
running, the vehicle decelerates
during that
time. The speed at which vehicle is running
when the control switch is turned off is stored
in the
memory, and the vehicle automatically
returns
to the stored speed.
3) Tap-down function: When the SET/COAST
switch is turned on and off instantaneously
while the vehicle is running, the vehicle decel­
erates a mile for each on/off operation. The
vehicle speed at
which the vehicle was run­
ning when the SET/COAST was turned off last
is stored in the
memory, and the vehicle auto­
matically returns to this stored speed.
2. RESUME/ ACCEL SWITCH FUNC­
TION
1) Resume function: When the RESUME/
ACCEL switch is turned
on/off after the system
is
temporarily deactivated by pressing the
brake or clutch pedal while the vehicle is
running,
the vehicle resumes. The speed
stored before the system
was released.
2) Accelerate function: When the RESUME/
ACCEL switch is kept on after the system is
released completely, the vehicle accelerates
its speed
during that time. The vehicle speed
at
which the vehicle was running when the
switch
was turned off is stored in the memory,
and the vehicle automatically returns to this
speed.
3) Tap-up function: When the RESU ME/ACCEL
switch is
turned on and off instantaneously
while the vehicle is running, the vehicle decel­
erates a mile for each on/off operation. The
vehicle speed at
which the vehicle was run­
ning when the switch was turned off last is
stored in the
memory, and the vehicle auto­
matically returns to this stored speed.

, cCi" <0 CD I ....
( (
1-10
CRUISE CONTROL SW,
CRUISE
CANSEL SW,
!COMBINATION
SWl
VEHICLE
SPEED
SENSOR
!METER}
i
CRUISE MAIN, AUTO CRUISE
INDICATOR LIGHT
CLUTCH
PEDAL
IM[T)
~
. //
BRAKE PEDAL
~~
RELAY &
FUSE BOX
B-2
vi"""
(FL-1
FL-2}
C-3g\j;~
PUMP&VSV
RELAY:
CRUISE
MAIN BATTERY--
/
H-41
··,.
,:-,
\
·.,"-
~DIODE
8-45
'"-FUSE
BOX IC-3, C-4, C-10,
C-14)
CRUISE
CONTROL
MAIN
SW
(
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n ::D c c;; m n 0 ~ 0 r-fD OJ I w

98-8 CRUISE CONTROL
QUICK CHART FOR POSSIBLE CAUSE
1. Cruise control inoperative
CHECK POINTS POSSIBLE CAUSE
Fuse C-4 (10A) Burned out
Cruise control main relay Defective circuit inside relay
Main switch
Contact point does not switch to ON
SET/COAST SW Contact point does not switch to ON
Clutch switch (M/T)
Contact point does not switch to ON
Brake switch Normal close side of point does not switch to ON
Pump & VSV Defective valve or vacuum pump (inoperative)
Vehicle speed sensor Open or short circuit
Vacuum hose Disconnected, Bent, Crack, Crush
Actuator Restriction
or out of link
Cable
harness Disconnected connector, Open circuit
Cruise
control unit Defective circuit inside control unit
2. Cruise speed unstable
CHECK POINTS POSSIBLE CAUSE
Vehicle
speed sensor Open or short circuit
Vacuum hose
Disconnected, Bent, Cracked, Crushed
Pump & VSV Defective valve (leakage)
Actuator Restriction,
defective or disconnected
Cruise
control unit Defective circuit inside control unit
Accelerator cable
Incorrect free play of accelerator pedal COUNTERMEASURE
Replace
Replace
Repair or replace
Refer to cruise control
SW
inspection
Refer
to clutch SW
inspection
Refer
to brake SW
inspection
Replace
Refer to speedometer
inspection
Repair
or Replace
Repair or Replace
Repair
Replace
COUNTERMEASURE
Refer to speedometer
inspection
Repair
or Replace
Replace
Repair or Replace
Replace
Readjust
•