warning ISUZU TROOPER 1995 Workshop Manual

8-328 CHASSIS ELECTRICAL
A/T INDICATOR LIGHT BULB
B REMOVAL
Preparation: Disconnect the battery ground cable.
Fig.
8-369
1. Meter assembly
• Refer to the meter assembly removal steps in
this section.
2.
A/T shift indicator light bulb
• Turn the bulb socket counterclockwise by
using the
long nose pliers. (Fig. 8-369)
B INSTALLATION
To install, follow the removal steps in the reverse
order.
WARNING LIGHT BULB, INDICATOR
LIGHT
BULB, ILLUMINATION LIGHT
BULB
B REMOVAL (FIG. 8-370)
Preparation: Disconnect the battery ground cable.
2. Socket & bulb 1. Meter assembly
Fig. 8-370
1. Meter assembly
• Refer to the meter assembly removal steps in
this section.
2.
Socket and bulb
• Hold the bulb socket by hand and rotate it
counterclockwise to remove them from the
meter body.
3.
Bulb
• Pull out the bulb from the socket.
B INSTALLATION
To install, follow the removal steps in the reverse
order.
VEHICLE SPEED SENSOR (INSTALLED
ON
THE TRANSMISSION)
Fig. 8-371
The vehicle speed sensor is installed on the rear
portion of the transmission. (Fig. 8-371)
The number of pulses generated is four pulses per
one rotation
of the pinion shaft.
..

OIL PRESSURE UNIT
(1!] INSPECTION
Measure the resistance value ofthe oil pressure unit
with the circuit tester. (Fig. 8-377)
Replace the
unit when the result of inspection is found
abnormal.
Pressure
(kPa)
Resistance value (Q)
Fig. 8-377
OIL PRESSURE SWITCH
(1!] INSPECTION
98 981
81 30
I~~ Check the continuity between the switch termi­
nal and the body ground with the engine at idle.
(Fig. 8-378)
Replace the switch when the result
of inspection
is
found abnormal.
Fig. 8-378
CHASSIS ELECTRICAL 8-331
(1!] CIRCUIT INSPECTION (FIG. 8-379)
Fig. 8-379
1. Start the engine.
2. When disconnecting the oil pressure switch con­
nector then connecting the harness side connec­
tor to the ground, check to see if the oil pressure
warning light lights up.
When the
light will not light up, check the circuit
between the meter and the oil pressure switch,
and repair
an open circuit if necessary.
FUEL TANK UNIT
The tank unit varies the internal resistance according
to the float position (fluid level) to operate the fuel
meter needle.
It is also designed
to warn the driver of low fuel level
by illuminating the fuel warning light. (Fig. 8-380)
Fig. 8-380

8-332 CHASSIS ELECTRICAL
i1!]1NSPECTION
~1.
£ ·= 0'1 ~ N ~ !:!i E
E
E E
0 M (I) ..., ... ...
Check the resistance between the connector
terminals 1 [E[I and 2 [E[J while shifting
the float from "E" to "F" point.
When
the resistance shows no change, or
deflects largely from the specified value, re­
place the fuel tank unit. (Fig. 8-381)
F
E .:: E~ ...... ...,::;
X
E
NOTE:
When the resistance value at E point is checked,
connect
the terminal 2 ~ to the battery (+) ter­
minal and 1 [E[] to the battery (-) terminal under
the condition that ambient temperature is between
20°C and 30°C (68°F and 86°F).
.. ,
I I I
·-·
Float position Resistance value (Q)
F point 17 ± 0.8
1/2 point 45± 1.5
E
point 120±5
Fig. 8-381
2. Check the resistance value between the fuel tank 1++1 REMOVAL (FIG. 8-383) unit connector terminals 1 ~and 4 [£:[].
(Fig. 8-382) Preparation: Disconnect the battery ground cable.
Replace the fuel tank unit when the result of
inspection is found abnormal.
Float
position Terminal No. Resistance
value (Q)
X point Undercover (Light up point 1-4 35.9-18 of low fuel Fig.
8-383 warning light)
Fig. 8-382
Ill

1. Fuel tank
• Refer to fuel tank removal steps in Section 6C
"ENGINE FUEL."
2. Fuel tank unit
• Disconnect the connectors.
• Remove the five screws.
B INSTALLATION
To install, follow the removal steps in the reverse
order.
BRAKE WARNING LIGHT
Fig. 8-384
The brake
warning light is connected in series with the
parking brake switch
installed to the parking brake
lever bracket. The
light comes on when the parking
brake lever is
pulled, and goes out when the parking
brake lever is
fully released. (Fig. 8-384)
Fig. 8-385
The brake warning
light switch, connected in parallel
with the brake fluid warning light, is designed to turn
on the brake warning light when the brake fluid in the
tank gets
below the specified level. (Fig. 8-385)
CHASSIS ELECTRICAL 8-333
"f CAUTION:
The parking brake indicator light illuminates to
warn the driver that the parking brake is on. This
light does not indicate the condition of the oper­
ability of the parking brake.
~ INSPECTION OF THE PARKING BRAKE
INDICATOR LIGHT CIRCUIT (FIG. 8-386)
Fig. 8-386
1. Disconnect the parking brake switch connector.
2. Connect the harness side connector to the ground.
3. Check to see if the indicator light comes on with
the starter switch "ON".
Check the bulb or the harness when the result of
inspection is found abnormal.
~ INSPECTION OF THE BRAKE FLUID
LEVEL WARNING LIGHT CIRCUIT
(FIG.
8-387)
Fig. 8-387
1. Disconnect the brake fluid switch connector.
2. Connect the harness side connector terminals.
3. Check to see if the indicator light comes on with
the starter switch "ON".
Check the bulb or the harness when the result of
inspection is found abnormal.

8-382 CHASSIS ELECTRICAL
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)-AIR BAG
The system consists of the starter switch, Diagnostic Energy Reserve Module (OERM), dual pole arming
sensor,
SRS coil assembly, inflator module (driver & passenger), forward sensor and warning light.
SRS is mainly comprised of the deployment loop and the DERM.
The main function of the deployment loop is to flow current into the inflator modules inside the steering
wheel (driver side) and the passenger side instrument panel (passenger side) to inflate the air bag. The
forward sensor
(LH and /or RH) gets activated by a shock caused by collision during running of a vehicle, the
current
from the battery flows into the inflator modules through dual pole arming sensor, so that the air bag
is
inflated.
The DERM supplies the current to the deployment loop to ensure that the air bag is inflated, if the power
circuit between battery and deployment loop is cut off by the shock of collision.
In
addition, the DERM monitors a voltage drops between components, and if the voltage drops below the
specified
value, the driver is alerted by the "AIR BAG" warning light in meter assembly.
Refer to Section 9J "SUPPLEMENTAL RESTRAINT SYSTEM (SRS)-AIR BAG" for details.
OPERATION OF THE CIRCUIT
DRIVER
INFLATOR MODULE
FOWARD
SENSOR-LH
D
D
STARTER SW
D
1
DUAL POLE ARMING SENSOR
PASSENGER
INFLATOR
MODULE
FORWARD
SENSOR-RH
NOTE: Arrow marks "c::::>" indicate the direction of current
Fig. 8-438
•

9B-36 CRUISE CONTROL
B REMOVAL (FIG. 98-21)
Preparation: Disconnect the battery ground cable.
Vacuum hose
Fig. 98-21
1. Pump
• Disconnect the connector.
• Disconnect the vacuum hose.
• Remove the pump fixing screws.
2. Actuator
• Disconnect the inner cables of the actuator at
the accelerator
pedal.
•
Remove the outer cable clips.
• Remove the actuator fixing screws.
E) INSTALLATION
To install, follow the removal steps in the reverse
order, noting
the following point.
1. Take care not to bend the cable excessively.
BRAKE SWITCH
~ INSPECTION
2 1
Push rod
~
~'
s ~ 1
Stoplight Depress brake pedal
(oush rod out)
Cruise Depress brake
pedal
control (push rod in)
Fig. 98-22
I B-131
2 3
o--o
4
~1. Check the installation condition of the brake
switch.
• Refer to the brake switch of "STOPLIGHT
AND REAR DEFOGGER" section in this
manual.
2. Check the continuity between the switch con­
nector terminals. (Fig. 98-22)
3. Check to see if the push rod operates
smoothly. Adjust, repair
or replace the brake switch
when the result
of inspection is found abnor­
mal.
B REMOVAL AND INSTALLATION
1·++·1 Refer to the brake switch of "STOPLIGHT AND
REAR DEFOGGER" section in this manual.
CLUTCH SWITCH
~INSPECTION
I B-161 1
rnll2a-~~
~ s 1 2
Release clutch pedal 0 ~ ~
(Push rod in)
Depress
clutch pedal
~1.
(Push rod out)
Fig. 98-23
Check the installation
condition of the clutch
switch.
• Refer to the clutch switch of "METER AND
WARNING/INDICATOR LIGHT" section in
this
manual.
2. Check the continuity between the switch con­
nector terminals. (Fig. 98-23)
3. Check to see if the push rod operates
smoothly. Adjust, repair
or replace the clutch switch
when the result of inspection is found abnor­
mal.
B REMOVAL AND INSTALLATION
1••1 Refer to the clutch switch of "METER AND ...-...
WARNING/INDICATOR"
section in this manual. ,...........

98-38 CRUISE CONTROL
VEHICLE SPEED SENSOR (INCORPO­
RATED IN SPEEDOMETER)
(1!] INSPECTION
GND GND
SEN 4P
~
I Red(+) Black(-) Black(-) Red(+)
a
I
4P GND 4P GND
4P-GND
13.5K-16.5K 00
Note: Use an analog type circuit tester.
Fig. 98-25
~~~ Removethespeedometerfromthemeterassem-DIODE
bly, and measure the resistance value between
the
terminals. (Fig. 98-26) IL•IINSPECTION
Replace the speedometer assembly when the
result of inspection is found abnormal.
B REMOVAL AND INSTALLATION
1•+1 Refer to Section 8 "METER AND WARNING/
INDICATOR LIGHT"
for vehicle speed sensor
removal and installation steps.
I B-451
~
Terminal No. 1 2
Connection A
G 0
pattern
0 G 8
Fig.
98-26
I~~ There should be continuity in either A or 8 when
a circuit tester is connected
with diode terminal.
(Fig. 98-26)
Replace the diode when the result of inspection
is
found abnormal.
..

Supplemental Restraint System 9J-1
SECTION 9J
SUPPLEMENTAL RESTRAINT SYSTEM
(SRS)
WARNING: THIS VEHICLE IS EQUIPPED WITH A SUPPLEMENTAL INFLATABLE RESTRAINT SYSTEM (SRS).
REFER TO WARNING IN THIS SECTION UNDER "ON-VEHICLE SERVICE" AND THE SRS COMPONENT AND
WIRING LOCATION VIEW IN THIS SECTION BEFORE PERFORMING SERVICE ON OR AROUND SRS
COMPONENTS OR WIRING. FAILURE TO FOLLOW WARNING COULD RESULT IN POSSIBLE AIR BAG
DEPLOYMENT, PERSONAL INJURY, OR OTHERWISE UNNEEDED SRS REPAIRS.
TABLE OF CONTENTS
SUPPLEMENTAL RESTRAINT SYSTEM
(SRS)
SECTION 1 -INTRODUCTION
CAUTION: WHEN FASTENERS ARE REMOVED, ALWAYS REINSTALL THEM AT THE SAME LOCATION
FROM WHICH THEY WERE REMOVED. IF A FASTENER NEEDS TO BE REPLACED, USE THE CORRECT PART
NUMBER FASTENER FOR THAT APPLICATION. IF THE CORRECT PART NUMBER FASTENER IS NOT
AVAILABLE, A FASTENER OF EQUAL SIZE AND STRENGTH (OR STRONGER) MAY BE USED. FASTENERS
THAT ARE NOT REUSED, AND THOSE REQUIRING THREAD LOCKING COMPOUND WILL BE CALLED OUT.
THE CORRECT TORQUE VALUE MUST BE USED WHEN INSTALLING FASTENERS THAT REQUIRE IT. IF THE
ABOVE CONDITIONS ARE NOT FOLLOWED, PARTS OR SYSTEM DAMAGE COULD RESULT.
GENERAL DESCRIPTION • • • . • . . . . • . . . . . . . . . • . . . . • . . . . . . . . • . . . . . . . . • . . . . • . • . . 3
Restraint Devices • • • • • • • • • • • • • • • • • • • • • • • • • • .. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 3
'W' System Description • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 4
SRS Component and wiring Location View . . . . . . • . . . . . . . . . . . • . . . . • . . . . . . . . . . • • 5
COMPONENT DESCRIPTION • • . .

. .
• . . • . .
.
• . . • . . . . . . . . . . . . . . . . . • . • . • . . . . • . • • . . 6
DERM ••••••••••••••••••\
••••••••••••••••••\
••••••••••••••••••\
•••••••• ~ • • • • • 6
"AIR BAG"Warnlng Lamp • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • .. • • • • • • • • • • • • 6
Dual Pole Arming Sensor • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 6
Discriminating Sensors • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 6
SRS Coli Assembly • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 7
Inflator Modules • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 7
Steering Column • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 7
Knee Bolster • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 7
DEFINITIONS • • . • . . • • • . • • . • • • • • . • . . • • . • . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . • • • • • • 8
DIAGNOSIS • • • • • • • • • • • • • • • • • • • • • • • • • • • . • • • • • • . • • • • • . . • • . . . . • • • • • . • • • • • • • • • • • 1 0
Diagnostic Trouble Codes • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 1 0
Scan Tool Diagnostic • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 1 0
Use of Special Tools • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 1 0
SRS CONNECTOR BODY FACE VIEWS . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . • . . . . . 11
REPAIRS AND INSPECTION REQUIRED AFTER AN ACCIDENT . . . . . • . . . . . . . . . . . 12
Accident With Deployment-component Replacement and Inspections • • • • • • • • • • • • • • • • • • 12
Accident With or Without Deployment-Component Inspections • • • • • • • • • • • • • • • • • • • • • • • 12
Sensor Replacement Guideline ••••••••• II • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 12
Wiring Damage ••••••••••••••••••\
••• II • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 12
SRS Conector (Plastic Body and Terminal Metal Pin) Damage • • • • • • • • • • • • • • • • • • • • • • • • • 12

9J-4 Supplemental Restraint System
'"""'t::~h-l--"b~RM PASSENGER SlOE HIGH
SYSTEM DESCRIPTION
The main portions of the SRS are the deployment loops ~
and the Diagnostic Energy Reserve Module(DERM).
The main function of the deployment loops is to supply
current through the inflator modules,which will cause
deployment of the air bags in the event of a frontal crash
of sufficient force, up to
30 degrees off the centerline of
the vehicle.The dual pole arming sensor, SRS coil
assembly(
driver side only), inflator modules, LH forward
discriminating sensor and
RH forward discriminating
sensor make up the
deployment loops. The dual pole
arming sensor switches power to the inflator modules on
the high side(power side) of the
deployment loops. Either
of the discriminating sensors can
supply ground to the
inflator modules on the low side (ground side) of the
loops. The inflator modules are only supplied sufficient
current to
deploy when the dual pole arming sensor and
at
least one of the discriminating sensors are closed
simultaneously.
A function of the DERM is to supply the deployment loops
with a 36-Volt Loop Reserve(36VLR) to ensure sufficient
energy to
deploy the air bags if the ignition feed to the
dual pole arming sensor is lost during a frontal crash.
Another function of the DERM is electrical system
diagnostics. The DERM monitors the deployment loops
in conjunction with the resistors in the dual pole arming
sensor, LH
forward discriminating sensor and RH
forward discriminating sensor. These resistors make it
possible for the DERM to detect circuit and component
malfunctions within the deployment loops. The DERM
monitors the
voltage drop across each component within
the
loops during normal non-deployment operation. If
the monitored voltages fall outside of expected limits, the
DERM
will indicate a malfunction through the storage of
a diagnostic trouble code and the illumination of the "AIR
BAG"
warning lamp.

9J-6 Supplemental Restraint System <
COMPONENT DESCRIPTION
DERM
CAUTION: DO NOT OPEN THE DERM CASE FOR
ANY REASON. TOUCHING THE CONNECTOR PINS
OR SOLDERED COMPONENTS MAY CAUSE
ELECTROSTATIC DISCHARGE DAMAGE. REPAIR
OF A MALFUNCTIONING DERM IS BY
REPLACEMENT ONLY.
The DERM is designed to perform the following functions
in the SRS:
1. Energy Reserve- The DERM maintains two 36-Volt
Loop Reserve(36VLR) energy supplies to provide
deployment energy when the vehicle voltage is low
or lost in a frontal crash.
2. Malfunction Detection-The DERM performs
diagnostic monitoring of SRS electrical components.
3. Malfunction Recording- The DERM provides SRS
diagnostic trouble code information through a scan
tool.
4. Driver Notification- The DERM warns the vehicle
driver of SRS malfunctions by controlling the "AIR
BAG"
warning lamp.
5. Frontal Crash Recording- The DERM records the
SRS status during a frontal crash.
The DERM is connected to the
SRS wiring harness by
a
24-way connector. This harness connector uses a
shorting
clip across certain terminals in the contact area.
This shorting
clip connects the "AIR BAG" warning lamp
to ground when the DERM harness connector is
disconnected. This will cause the "AIR BAG" warning
lamp to come "ON" steady whenever the ignition switch
is at the RUN,BULB
TEST or START positions with the
DERM disconnected.
"AIR BAG"WARNING LAMP
Ignition voltage is applied to the "AIR BAG" warning lamp
when the ignition switch is at the RUN,BULB TEST or
START positions. The DERM controls the lamp by
providing ground with a
lamp driver. The "AIR BAG"
warning lamp is used in the SRS to do the following:
1. Verify lamp and DERM operation by flashing SEVEN
times when the ignition switch is first turned"ON".
2. Warn the vehicle driver of SRS electrical system
malfunctions which could potentially affect the
operation of the
SRS. These malfunctions could
result
in non-deployment in case of a frontal crash
or deployment for conditions less severe than
intended.
The "AIR BAG" warning lamp is the key to driver
notification of SRS malfunctions. For proper lamp
operation, refer to the "SRS Diagnostic System Check"
in this section.
DUAL POLE ARMING SENSOR ~
The dual pole arming sensor is a protective switch
located in the high side(power side) of the deployment
loops.
The dual pole arming sensor is calibrated to close
at low level velocity changes(lower than the
discriminating sensors).
This ensures that the
inflator modules are connected
directly to the "36 VLR" outputs of the DERM or "Ignition
1" voltage
when any discriminating sensor closes.
The dual pole arming sensor consists of: a sensing
element, two sets of normally open switch contacts,
diagnostic resistors and diodes. The sensing
element
closes
both sets of switch contacts when the velocity of
the
vehicle changes at a rate indicating a potential need
for
deployment.
Two of the diagnostic resistors are connected in parallel
with the switch contacts. This allows a small amount of
current to
flow through each of the deployment loops
during normal, non-deployment operation. This current
flow results in voltage drops across each component in
the
deployment loops. The DERM monitor these voltage
drops to detect circuit or component malfunctions. There
are two
additional diagnostic resistors within the dual
pole
arming sensor which allow the DERM to monitor the
voltage supplied to the high side ofthe deployment loops.
These monitored voltages are used by the diagnostic
logic of the DERM to make a more precise determination
of the
actual deployment loop malfunction. ~
The diodes within the dual pole arming sensor provide
isolation between the "36VLR" outputs of the DERM and
the
vehicle electrical system "Ignition 1" voltage. The
presence of the diodes prevents a direct continuity
measurement through the
dual pole arming sensor
resistors to
terminals"3","4" or "5".
DISCRIMINATING SENSORS
The discriminating sensors are protective switches wired
in parallel on the low side(ground side) of the deployment
loops.
These sensors are calibrated to close with velocity
changes which are severe enough to warrant
deployment.
The discriminating sensors consist of a sensing element
and normally open switch contacts when the vehicle
velocity changes are severe enough to warrant
deployment.
A diagnostic resistor is connected in parallel with the
switch contacts within the
LH forward discriminating
sensor and
RH forward discriminating sensor. These
parallel resistors supply the ground path for the current
passing through the
deployment loops during normal,
non-deployment operation. This current flow results in
voltage drops across each component within the
deployment loops. The DERM monitors these voltage
drops to detect circuit or component malfunctions.
II