stop start ISUZU TROOPER 1995 Repair Manual

GROUNDING POINT
REFERENCE TABLE
Connector No.
Cable harness
~
~
I B-1a1
Body harness
I B-191
I B-261
1 lc-16 I
2IC-16 I
3IC-16 I
4IC-16 I
Engine room
5IC-16 I
harness
6IC-16 I
7IC-16 I
aiC-16 1
Location
Body-RH
Body-LH
Body-center
Fender-LH
CHASSIS ElECTRICAL 8-29
Parts (Load)
Remind buzzer, Key remind switch (Starter
switch),
Sun roof control unit, Sun roof motor, Sun roof switch, Safety stop switch, Limit
switch
Door lock key switch (Front-RH), Cruise control
unit, Cigar lighter, Door mirror (RH), Front door
key switch (RH), Front door lock actuator (RH),
Fan switch, Starter relay, Front
door lock & power window switch (LH, RH), Front power window motor
Door lock key switch (Front-LH), Front power window motor (LH), Door mirror (LH), Front
door key switch (LH), Front door lock actuator
(LH), Rear wiper intermittent relay, Front door
lock & power window switch (LH)
Starter relay, Headlight
wiper switch,
Anti-theft controller,
Dimmer·passing switch, Fog light switch, Headlight, Lighting
relay, Fog
light relay, Illumination controller,
Illumination light, Rear defogger switch, Rear
defogger relay, Flasher unit,
Power window relay, Cruise control main relay, Kick-down
switch, Audio, Intermittent relay (front), Mode SW, Tail relay, Lighting SW, Cornering light
relay, Glove box switch, Digital clock,
Transmission control module, Heater & A/C
relay, Front
door key switch, Door mirror
control switch, Door mirror folding switch,
Door mirror defogger switch, Meter assembly
Seat heater, Seat heater switch, Fuel pump, Fuel pump relay, Seat belt switch, Remind
buzzer, Power and winter switch, Shift lock
controller, Rear
door lock actuator, Fuel tank
unit, Power seat SW, Front tilt motor & switch,
Rear tilt motor & switch, Slide motor, Recliner
motor & switch, Rear power window switch
(LH, RH), Rear power window motor (LH, RH),
Seat belt warning light
Headlight
wiper motor
Power steering pressure SW
4WD switch, 4WD indicator (meter), Brake fluid
SW, Oxygen sensor (M/T)
Electronic brake control
module
Front side marker light (LH, RH), Cornering
light, Cornering light switch (Combination
switch), Front turn signal light, Turn signal light switch (Combination switch), Parking light (LH, RH)
Fog light, Fog light relay
Hydraulic
unit
Oxygen sensor (AfT), ABS & Upshift relay,
Transmission SW

STARTER SWITCH (FIG. 8-59)
Fig. 8-58
~
~
LOCK Removed
OFF
ACC Inserted
ON
START
4
(62)
CHASSIS ELECTRICAL 8-43
The starter switch positions are LOCK, OFF, ACC, ON
and START. Turning the starter key to these positions
provides a circuit
for starting the engine, the opera­
tion of accessories, or stops the engine.
~ INSPECTION
1 ~ 1 Check the continuity between the starter switch
connector terminals. (Fig. 8-59)
1
Repair or replace the switch when the result of
inspection is found abnormal.
5 3 2 7 8 6
(ACCl (IG2l (STl (61) (IG1l (KEY(£)) (KEY8l
o----o
Fig.
8-59

CHASSIS ELECTRICAL 8-47
ENGINE CONTROL MODULE (ECM)
GENERAL DESCRIPTION
The ECM is used to control the fuel system of the
vehicle, especially in controlling the following items.
1. FUEL CONTROL
The amount of fuel and air sent into the combus­
tion chamber is controlled by controlling the fuel
sent through the injector.
2. ELECTRIC FUEL PUMP (INSTALLED IN
THE FUEL TANK)
The in-tank fuel pump is controlled by the ECM.
When starter switch is turned on, the pump will
run for 2 seconds, then stop unless the engine is
cranking
or running.
3. IGNITION CONTROL
The system is controlled by the spark timing con­
trol function of the ECM.
4. CIRCULATION OF EXHAUST GAS
The system controls the formation of NOx by
returning a small amount of exhaust gas to the
intake manifold
through the control valve.
'-" lAC: Idle air control
5. CONTROL OF AIR CONDITIONING (A/C)
For improved engine idling performance, the sys­
tem controls the operation of the air conditioner
by regulating the
clutch operation ofthe A/C com­
pressor in accordance
with changes in operation.
6. IDLE AIR CONTROL
The system controls the lAC Valve for the desired
idle speed in accordance
with changes in
operation.
7. DIAGNOSIS OF TROUBLES
When a sensor detects any signal that the ECM is
in
an abnormal condition, the ECM turns on the
malfunction
indicator (CHECK ENGINE) light in
the meter, and stores at the same
time the corre­
sponding diagnostic
trouble code (DTC) in the
memory to indicate to which system or circuit the
trouble represented by the
DTC belongs.
The ECM inspection connector (data link connec­
tor) is used
to retrieve the DTCs stored from the
ECM.
Refer to Section 6 "ENGINE DIAGNOSIS" for de­
tails.

I ..
8 -70 CHASSIS ELECTRICAL
When placing a live inflator module on a bench
or other surface, always face the bag and trim
cover up, away from the surface. This is neces­
sary so that a free space is provided to allow the
air bag to expand in the unlikely event of acci·
dental
deployment.
4. Steering wheel
• Refer to STEERING WHEEL REPLACEMENT in
Section 3F4.
5. Lighting switch (Combination switch)
• Disconnect the switch connector.
• Remove four screws.
• Remove the lighting switch together with SRS
coil assembly.
'\f CAUTION:
Do not remove SRS coil assembly from the com·
bination switch assembly.
E) INSTALLATION
To install, follow the removal steps in the reverse
order, noting the
following points.
1. Check to see if the vehicle is in the straight driving
condition and turn the rotary section of the SRS
coil assembly provided to the upper surface ofthe
lighting switch (combination switch) clockwise
fully until it stops. Then from where it stops, turn
it back about 3 rotations to set the alignment
marks together before installing the steering
wheel. (Fig. 8-83)
Alignment mark
Fig. 8-83
2. Tighten the steering shaft nut to the s ecified
torque.
Nut torque N·m (lb.ft)
3. When connect the double lock type of nflator
module connector, insert the connecto com­
pletely
and lock at outside. Imperfect locki g may
cause malfunction of SRS system circuit.
4. When installing the steering cowl, be sure o pass
the harnesses
through the route as show in the
illustration so that the starter switch, th com­
bination switch and the inflator module
will not get caught. (Fig. 8-84)
Starter switch
harness
Combination
switch harness
~~ ~
Fig. 8-84
cowl
•

I
8 -92 CHASSIS ELECTRICAL I
STOPLIGHT AND REAR DEFOGGER I
GENERAL DESCRIPTION i .-_
The circuit consists of the stoplight, stoplight switch (vehicles w/o cruise control), brake switch (ve~icles w/
cruise control), rear defogger, rear defogger switch, rear defogger relay and trailer harness conn~ctor for
stoplights. i
With the brake pedal depressed, the stoplight switch or the brake switch is turned on to illumi~ate the
stoplight. The brake switch controls not only the operation of the stoplight but also the input of th~ cruise
cancel signals to the cruise control unit. 1
When the rear defogger switch is turned on with the starter switch on, the battery voltage is applie to the
rear
defogger through the rear defogger relay to operate the rear defogger.
The rear
defogger switch is provided with a timer. When the operation time of the timer elapses w ich has
been set in advance at manufacture,
the switch is automatically turned off. (The timer operating time is
normally about 30 minutes).
OPERATION OF THE REAR DEFOGGER CIRCUIT
STARTER SW ..------,
BATTERY(+)
~----------------0
llJ,
f-®-
RR DEFOGGER
~
SW
~
>'f RR DEFOGGER ~~
RELAY "ON" :4r 2 1-
(When RR ?
defogger SW HON"I
~ [b
RR DEFOGGER
NOTE: Arrow marks II => II indicate the direction of current
Fig. 8-115
~
•

STARTER SWITCH
Refer to "START AND CHARGING" in this section.
'-' STOPLIGHT SWITCH (FOR VEHICLES
W/0 CRUISE CONTROL)
~ INSPECTION
1. Check to see if the stoplight switch is installed
correctly
to the specified position. Adjust the
position when the result
of the inspection is
found abnormal.
·
2. Check to see if there is any continuity between
the terminals
of the stoplight switch. (Fig. 8-119)
Replace the switch when the result of inspection
is found abnormal.
t[J I B-141
-----==== Terminal No.
SW position
--Depress brake pedal (Push rod out)
Release brake pedal (Push rod in)
Fig. 8-119
B REMOVAL (FIG. 8-120)
1
2
0.: -o
Preparation: Disconnect the battery ground cable.
1. Stoplight switch
• Disconnect the connector.
• Loosen the lock nut of the switch.
• Remove the switch by turning it.
Lock nut 1. Stoplight switch
Fig. 8-120
CHASSIS ELECTRICAL 8-101
B INSTALLATION
To install, follow the removal steps in the reverse
order, noting the
following points.
1. Check to see if the brake pedal has been returned
by the return spring to the specified position.
2. Turn the stoplight switch clockwise until the tip
of the threaded portion of the switch contacts the
pedal arm.
3. Turn the switch counterclockwise until the space
between the
tip of the threaded portion and the
pedal arm is
0.5 to 1.0mm (0.02 -0.04in.)
(Fig. 8-121)
0.5-1.0mm (0.02·0.04in} Stoplight switch
Fig. 8-121
BRAKE SWITCH (FOR VEHICLES WI
CRUISE CONTROL)
~ INSPECTION
1. Check to see if the brake switch is installed
correctly
to the specified position. Adjust the
position
if the result of inspection is found
abnormal.
2. Check to see if there is any continuity between
the terminals
of the brake switch. (Fig. 8-122)
Replace the switch
when the result of inspection
is
found abnormal.
2 1
Pu•h ~·· lB·13l
4 3 -..
~0. SWp 1 2 3 4
Stoplight Depress
brake pedal
(push rod out)
Cruise Release brake pedal
o-f-o control (push rod in)
Fig. 8-122

CHASSIS ELECTRICAL 8-137
Warning function
Operational conditions
The
warning light in the meter assembly turned on about 6
seconds
from the moment the starter switch is turned on.
Fasten the seat
belt
The buzzer sounds for about 6 seconds when the starter switch
is turned on with the seat belt switch on (when the seat belt is
not used).
Key left in The
buzzer sounds when both the key remind switch and the
FRT
door switch -LH are turned on.
starter switch
To
stop the sound of the buzzer, turn on the starter switch.
Taillights left on The
buzzer sounds when the starter switch is turned
from the
"on• to "off" position while the taillights are on.

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
~ :a -t CJ) r-0 (") ~ 0 z
(") :::t ln en (i) m r­m ~ :;g n ~ r-eo I ..a ..... CD

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.