engine ISUZU TROOPER 1995 Workshop Manual

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.

8-340 CHASSIS ELECTRICAL
HEATER AND AIR CONDITIONING
GENERAL DESCRIPTION
The circuit consists of the pressure switch, NC switch, electric thermostat, blower motor, fan switch, magnet
clutch of the NC compressor, blower resistor and relay.
The start and stop of the NC is controlled by turning the NC switch on and off. The electric thermostat and the
ECM can stop the operation of the NC temporarily by disconnecting the magnet clutch under the
predetermined conditions
to adjust the room temperature, preventing the abnormal rise of the engine coolant
and reduce the engine load while the NC is in operation.
Refer
to Section 18 "AIR CONDITIONING" for detail.
OPERATING CONDITIONS OF A/C COMPRESSOR (MAGNETIC CLUTCH)
BATIERY(+)
--
~
A/C SW "ON"
~
HEATER & A/C RELAY "ON"
(The contact point is closed except
when starter SW is at ST or OFF position)
(S =:>
¢:!]
PRESSURE D
SW"ON"
¢:::l
~ FAN SW"ON"
u A/C THERMOSTAT
RELAY
"ON"
A/C COMPRESSOR
RELAY"ON"
ECM IA2l "ON"
MAGNETIC
CLUTCH lAIC COMPRESSOR)
"ON"
NOTE:
Arrow marks" =:> " indicate the direction of current
Fig. 8-394
~
1111

CRUISE CONTROL 98-17
@ INSPECTION OF THE PUMP & VSV, AND THE CIRCUIT
• DOES THE ACTUATOR CABLE FUNCTION
CORRECTLY?
• DISCONNECT
THE CONNECTOR OF THE PUMP & vsv.
• WITH THE PUMP & ACTUATOR SIDE CONNECTOR 2IC-37ICONNECTED TO THE BATIERY (+)
TERMINAL AND THE CONNECTOR 31 C-371 TO
GROUND,
IS THE OPERATING SOUND OF THE VACUUM PUMP HEARD?
• DISCONNECT THE VACUUM HOSE FROM THE
ACTUATOR.
• CONNECT 21 C-371 TO THE BATIERY (+)TERMINAL,
AND 31 C-371, 11 C-371 AND 41 C-371 TO GROUND. • IS THERE ANY NEGATIVE PRESSURE APPLIED TO THE VACUUM HOSE?
• CONNECT
THE VACUUM HOSE TO THE
ACTUATOR.
• CONNECT 2 [E;ll) TO THE BATIERY (+)TERMINAL,
AND 31 C-371, 11 C-371 AND 41 C-371 TO THE
GROUND.
• DOES THE ENGINE THROTILE OPERATE
CORRECTLY?
CONTINUED ON FOLLOWING
PAGE

98-28 CRUISE CONTROL
ON-VEHICLE SERVICE
IE BRAKE SWITCH ADJUSTMENT
(FIG. 9B-5)
0.5 -1.0 mm (0.02 -0.04 in.}
Fig. 98-5
1. Check to be sure that the brake pedal has been
completely returned by the return spring.
2. Disconnect the switch connector.
3. Loosen the lock nut of the switch.
4. Turn the switch clockwise until the tip of screw
portion of the brake pedal hits the pedal arm.
5. Turn the switch counterclockwise until the clear­
ance between the
tip of the screw portion and the
pedal arm becomes 0.5
to 1.0mm (0.02-0.04 in).
6. Tighten the lock nut.
7. Connect the switch connector.
IE CLUTCH SWITCH ADJUSTMENT
(FIG. 9B-6)
Clutch switch
--Clutch pedal
Fig. 98-6
1. Check to be sure that the clutch pedal has been
completely returned by
the return spring.
2. Disconnect the switch connector.
3. Loosen the lock nut of the switch.
4. Push the switch by hand until the push rod cannot
be seen from the tip portion of the switch.
5. Give the switch one reverse rotation.
6. Tighten the lock nut.
7. Connect the switch connector.
IE ACTUATOR CABLE ADJUSTMENT
(FIG. 9B-7)
Actuator
Adjust nut A
Adjust nut B
Fig. 98-7
1. Fix the accelerator pedal at the position where it
has been fully returned (with the throttle valve
fully closed).
2. Loosen the adjust nuts A and B.
3. With the outer cable pulled to the accelerator
pedal side (in the state
where the inner cable has
no play),
tighten the adjust nut A by hand until it
hits the bracket.
4. Tighten the adjust nut 8 to lock it.
STARTER SWITCH (FIG. 98-8)
Fig. 98-8
The starter switch is provided
with following switch
positions:
LOCK, OFF, ACC, ON, and START. Turning
the starter key to these positions completes a circuit
in
order to start and shut off the engine, and operate
the accessories.

9B-30 CRUISE CONTROL
1. Front console assembly
• Remove four screws.
• Remove the transmission shift lever knob.
• Remove the transfer shift lever knob.
• Disconnect the seat heater switch connectors
(If so equipped).
• Disconnect the "POWER & WINTER" switch
connectors (A/T only).
2. Lower cluster assembly
• Remove three screws.
• Disconnect the cigar lighter connectors.
• Remove the cigar lighter illumination bulb
socket.
• Disconnect the ashtray illumination bulb
connector.
3. Instrument panel driver lower cover
• Remove the engine hood opener.
• Remove three screws and clip.
•
Disconnect four fasteners.
4. Steering cowl
• Remove seven screws.
5. Starter switch
• Disconnect the connector.
• Remove the screw.
8 INSTALLATION
To install, follow the removal steps in the reverse
order noting the following point.
1. When installing the steering cowl, be sure to pass
the harnesses
through the route as shown in the
illustration so that the starter switch, the
combination switch and the SRS harness will not
get caught. (Fig. 98-11)
Starter switch
harness
Combination
switch harness
l._n!~~~o!_ module __..o .~ ~
Fig. 98-11
Steering cowl (Lower)
CRUISE CONTROL MAIN SWITCH
(1!1 INSPECTION
OI1
r-="'
-L
r= t-------uii4J~l "ltl1 u
l
1111ilr9Tsl7lels .,
:::o.,..o-
~ s 6 7 8 9 2 3
AUTO FREE
n
CRUISE ON ()-1---n
OFF FREE o-f--0
ON
Fig. 98-12
ltjl Check the continuity between the switch connec­
tor terminals. (Fig. 98-12)
Replace the cruise control main switch when the ~
result of inspection is found abnormal.

ACTUATOR CABLE DIAGRAM (FIG. 98-
18)
Engine control cable
CRUISE CONTROL 9B-35
Accelerator pedal
Fig. 98-18
~ INSPECTION
I C-371
E9
Circuit Tester
Resistance Current
connection (Q) (A)
Vent
valve 1-2 62-72 -
Safety valve 2-4 62-72 -
Vacuum pump 2-3 -Max. 2A
Fig. 98-19
I~~ Check the resistance and current values between
the
pump & VSV connector terminals. (Fig. 98-
19)
Repair or replace the pump & VSV when the
result of inspection is found abnormal.
IL1i'llnspection of operation (Fig. 98-20)
Apply the battery voltage between the pump & VSV
connector terminals, and check to see if the motor and
actuator operate
smoothly.
Repair or replace the pump & VSV when the result of
inspection is found abnormal.
I C-371
il
Check condition Operation
Connect connector
terminalll C-3~ I Motor operates
to battery(+} terminal and 3 C-37 to (-)terminal
In the condition abov~und Actuator cable is
connector
terminal 1 C-37 and pulled
41 C-371
In the condition abov
1e. disrnnect Cable is pulled back
connector
terminal 1 C-37 and
41 C-371
Fig. 98-20

9J-8 Supplemental Restraint System
DEFINITIONS
AIR BAG -An inflatable cloth cushion designed to
deploy in certain frontal crashes. It supplements the
protection offered by the seat belts by distributing the
impact load more evenly over the vehicle occupant's
head and torso.
ASYNCHRONOUS -Performed in a non-periodic
fashion,i.e.no defined time or interval.
B+-Battery voltage, the voltage available at the battery
at the time of the indicated measurement. With the key
"ON" and the engine not running, the system voltage will
likely be between 12 and 12.5 volts. At idle the voltage
may be 14 to 16 volts. The voltage could be as low as 1
0
volts during engine cranking.
BULB
CHECK-The DERM will cause the "AIR BAG"
warning lamp to flash seven times and then go "OFF"
whenever the ignition switch transitions to the RUN
position from any other ignition switch position and no
malfunctions are detected.
"CONTINUOUS MONITORING"-Tests performed by
the DERM on the
SRS every 1 00 milliseconds while
"Ignition
1" voltage is in the normal operating voltage
range at the DERM.
DATA LINK CONNECTOR(DLC)-Formerly "ALDL'', a
connector which allows communication with an
off-board computer, such as a scan
tool.
DATUM LINE-A base line parallel to the plane of the
underbody or frame from which all vertical
measurements originate.
DEPLOY-To inflate the air bag.
DEPLOYMENT
LOOPS - The circuits which supply
current to the inflator modules to deploy the air bag.
DERM -Diagnostic
energy reserve module which
provides reserve energy to the deployment loops and
performs diagnostic monitoring of
all SRS components.
DIAGNOSTIC TROUBLE CODE(DTC) -Formerly
"Code,"a numerical designator used by the DERM to
indicate specific
SRS malfunctions.
DRIVER CURRENT SOURCE-An output of the DERM
which injects current into the driver inflator module circuit
during the "Initiator Assembly Resistance
Test."
DRIVER INFLATOR
MODULE-An assembly located in
the steering wheel hub consisting of an inflatable air bag,
an inflator and an initiator.
DUAL
POLE ARMING SENSOR-A sensor on the high
side(power side) of the deployment loops that is
calibrated to supply voltage to the inflator modules when
the vehicle velocity changes are severe enough to
warrant arming of the air bags in preparation for
deployment.
EEPROM -Electrically Erasable Programmable Read ~
Only Memory. Memory which retains its contents when
power
is removed from the DERM.
FORWARD LH DISCRIMINATING SENSOR-A sensor
on the low side(ground side) of the deployment loops
which is calibrated to ground the inflator modules when
the vehicle velocity changes are severe enough to
warrant deployment of the air bags.
FORWARD RH DISCRIMINATING SENSOR-A sensor
on the low side(ground side) of the deployment loops
which
is calibrated to ground the inflator modules when
the vehicle velocity changes are severe enough
to
warrant deployment of the air bag.
FORWARD LH SENSOR Eng-Room HARNESS-An
assembly of two correct carrying wires which connects
the Forward
LH discriminating sensor to SRS harness.
FORWARD RH SENSOR Eng-Room HARNESS
JUMPER-An assembly of two current carrying wires
which connects the Forward
RH discriminating sensor to
the
SRS harness.
HIGHER PRIORITY FAULT-Each diagnostic trouble
code
is assigned a priority based on the detectability with
other DTCs present. The priority corresponds to the
detectability of the malfunction ONLY, and does NOT
relate to the criticality of the malfunction with respect to ~
deployment or non-deployment under any given
condition.
IGNITION CYCLE -The voltage at the PERM "Ignition
1"
inputs, with ignition switch "ON," is within the normal
operating voltage range for at least ten seconds before
turning ignition switch
"OFF."
IGNITION1
-A battery voltage(B+)circuit which is only
powered with the ignition switch in the RUN,BULB
TEST,or START positions.
INITIATOR-The electrical component inside the inflator
module which, when sufficient current flows, sets off the
chemical reaction that inflates the air bag.
"INITIATOR ASSEMBLY RESISTANCE TEST"-Tests
performed once each ignition cycle when no
malfunctions are detected during "Turn-ON" or
"Continuous Monitoring." This test checks for the correct
DERM configuration for the vehicle, shorts to
"Ignition 1"
in the deployment loops, high resistance or opens in the
"Driver
Side High," "Driver Side Low," "Passenger Side
High"
and "Passenger Side Low" circuits and measures
the resistance of the inflator assembly consisting of: 1)
Initiators, 2) SRS coil assembly(driver side only), 3)
Connectors and associated wiring.
NORMAL OPERATING VOLTAGE RANGE-The ~
voltage measured between the DERM "Ignition 1" ·
terminals and "Ground" terminals is between 7.25 and 16
volts.
•

9J-32 Supplemental Restraint System (SRS)
SRS DIAGNOSTIC SYSTEM CHECK
WARNING: TO AVOID DEPLOYMENT WHEN
TROUBLESHOOTING THE SRS, DO NOT USE
ELECTRICAL TEST EQUIPMENT SUCH AS A
BATTERY-POWERED OR AC-POWERED
VOLTMETER, OHMMETER, ETC., OR ANY TYPE OF
ELECTRICAL EQUIPMENT OTHER THAN THAT
SPECIFIED IN THIS MANUAL. DO NOT USE A
NON-POWERED PROBE TYPE TESTER.
INSTRUCTIONS IN THIS MANUAL MUST BE
FOLLOWED CAREFULLY, OTHERWISE PERSONAL
INJURY
MAY RESULT.
The diagnostic procedures used in this section are
designed to find and repair
SRS malfunctions. To get the
best results, it is important to use the diagnostic charts
and
follow the sequence listed below:
A. PERFORM THE "SRS DIAGNOSTIC SYSTEM
CHECK."
The "SRS Diagnostic System Check" must be the
starting point of any
SRS diagnostics. The "SRS
Diagnostic System Check" checks for proper "AIR
BAG"
warning lamp operation, the ability of the
DERM to communicate through the
"Serial Data" line
and whether SRS diagnostic trouble codes exist.
B. REFER TO THE PROPER DIAGNOSTIC CHART
AS
DIRECTED BY THE SRS DIAGNOSTIC
SYSTEM CHECK."
The "SRS Diagnostic System Check" will lead you to
the correct chart to diagnose any
SRS malfunctions.
Bypassing these procedures may result
in extended
diagnostic time, incorrect diagnosis and incorrect
parts replacement.
C. REPEAT THE "SRS DIAGNOSTIC SYSTEM
CHECK" AFTER ANY REPAIR OR DIAGNOSTIC
PROCEDURES HAVE
BEEN PERFORMED.
Performing
the "SRS Diagnostic System Check"
after all repair or diagnostic procedures will ensure
that the repair has been made correctly and that no
other malfunctions exist.
CIRCUIT DESCRIPTION
When the ignition switch is first turned "ON,""Ignition 1"
voltage is applied from the "C-22·C-23" fuse to the
DERM at the
"Ignition 1" input terminals "A9" and "A10"
and from the "C-21" fuse to the DERM at the "Redundant
Indicator Ignition 1" input terminal "B2". The DERM
responds by flashing the
"AIR BAG" warning lamp seven
times while performing tests on the
SRS.When the
engine is being cranked,
"Starter'' voltage is applied from
the
"C-1" fuse to the DERM at the "Crank" input terminal
"B10".The DERM responds by grounding the "SRS
Indicator"
output terminal "B 1" until "Starter" voltage is
removed from the "Crank" input. This results in the "AIR
BAG" warning lamp being "ON" steady during
cranking.After cranking, the DERM will flash the "AIR
BAG"
warning lamp six times and perform tests on the
SRS.
NOTES ON SYSTEM CHECK CHART ~
1. The "AIR BAG" warning lamp should flash seven
times after ignition is first turned
"ON."
2. The "AIR BAG" warning lamp should remain "ON"
steady during cranking.
3. When the "AIR BAG" warning lamp flashes four
times during
"Bulb Check" this indicates a
malfunction
in the redundant lamp driver circuitry.
These malfunctions are diagnosed by
DTC 62 chart.
4. After cranking, the "AIR BAG" warning lamp should
flash six times then go
"OFF."
5. Improper operation of the "AIR BAG" warning lamp
is indicated. This test differentiates a warning lamp
stays
"ON" condition from a warning lamp does not
come
"ON" condition.
6. This test checks for the proper operation of the
"Serial Data" line. This test will also determine
whether history diagnostic trouble codes are stored
and, if so, identify them.
7. This test checks for proper operation of the
"Serial
Data"
line. This test will also identify the stored
diagnostic trouble codes and
whether they are
current or history.
~
DIAGNOSTIC AIDS
The order in which diagnostic trouble codes are
diagnosed is very important. Failure to diagnose the
diagnostic trouble codes in the order specified may result
in extended diagnostic time, incorrect diagnosis and
incorrect parts replacement.

Supplemental Restraint System 9J-33
SRS DIAGNOSTIC SYSTEM CHECK
STEP
ACTION YES NO
1 NOTE "AIR BAG" WARNING LAMP AS IGNITION SWITCH IS GOTOSTEP2 GOTOSTEP3 TURNED "ON."
DOES WARNING
LAMP FLASH 7 TIMES?
2 NOTE "AIR BAG" WARNING LAMP AS ENGINE IS STARTED. GOTOSTEP4 GO TO CHART D. DOES WARNING LAMP COME "ON" STEADY DURING
CRANKING?
3 DOES WARNING LAMP FLASH 4 TIMES? GOTO DTC62. GO TO STEPS.
4 NOTE "AIR BAG" WARNING LAMP AFTER STARTING. GOTOSTEP6 GOTOSTEP7 DOES WARNING LAMP FLASH 6 TIMES THEN GO "OFF"?
5 DOES WARNING LAMP COME "ON" STEADY? GO TO CHART B. GO TO CHART C.
6 IGNITION SWITCH "OFF." IF
NO SRS DIAGNOSTIC TROUBLE CODES
CONNECT SCAN TOOL TO
DATA LINK CONNECTOR, ARE DISPLAYED. GOTO STEP 8. FOLLOW DIRECTIONS AS GIVEN IN THE SCAN TOOL
INSTRUCTION MANUAL.
IGNITION SWITCH "ON."
IF HISTORY DIAGNOSTIC TROUBLE CODES
REQUEST SRS DIAGNOSTIC TROUBLE CODE DISPLAY, ARE DISPLAYED. GOTO STEP 9. RECORD ALL HISTORY DIAGNOSTIC TROUBLE CODES,
SPECIFYING AS SUCH, ON REPAIR ORDER.
7 IGNITION SWITCH "OFF." IF DIAGNOSTIC TROUBLE CODES ARE
CONNECT SCAN TOOL TO DATA LINK CONNECTOR, DISPLAYED. GOTO STEP 10. FOLLOW DIRECTIONS AS GIVEN IN THE SCAN TOOL
INSTRUCTION MANUAL. IGNITION SWITCH "ON."
REQUEST SRS DIAGNOSTIC
TROUBLE CODE DISPLAY, RECORD ALL DIAGNOSTIC TROUBLE CODES SPECIFYING
AS CURRENT OR HISTORY ON REPAIR ORDER.
8
SRS IS FUNCTIONAL AND FREE OF MALFUNCTIONS.
NO FURTHER DIAGNOSIS IS REQUIRED.
9 IGNITION SWITCH "OFP'. WHEN DTC 83 IS SET, GO TO DTC 83 CHART. WHEN DTC 84 IS SET, GO TO DTC 84 CHART. FOR ALL OTHER HISTORY DIAGNOSTIC TROUBLE CODES, REFER TO "DIAGNOSTIC AIDS" FOR THAT
SPECIFIC DIAGNOSTIC TROUBLE CODE. A HISTORY DTC INDICATES THE MALFUNCTION HAS BEEN REPAIRED OR IS INTERMITTENT.
10 DIAGNOSTIC
TROUBLE CODES ARE DISPLAYED.
IGNITION SWITCH "OFF."
WHEN DTC 51 IS SET, GO TO DTC 51 CHART. DIAGNOSE REMAINING CURRENT DIAGNOSTIC TROUBLE CODES FROM LOWEST TO HIGHEST. WHEN ONLY HISTORY DIAGNOSTIC TROUBLE CODES EXIST, REFER TO "DIAGNOSTIC AIDS" FOR THAT SPECIFIC DIAGNOSTIC TROUBLE CODE. A HISTORY DTC INDICATES THE MALFUNCTION
HAS BEEN
REPAIRED OR IS INTERMITTENT.

9J-36 Supplemental Restraint System
TABLE B
"AIR BAG" WARNING LAMP COMES "ON" STEADY
CIRCUIT DESCRIPTION
When the ignition switch is first turned "ON," "Ignition 1"
voltage is applied from the "C-21" fuse to "Redundant
Indicator Ignition 1 ,"terminal "B2", and to the "AIR BAG"
warning lamp which is connected to "SRS Indicator,"
terminal "B1". The "C-22·C-23" fuses apply system
voltage to the
"Ignition 1" inputs, terminals "A9" and
"A10". The DERM responds by flashing the "AIR BAG"
warning lamp 7 times. If "Starter" is outside of the normal
operating voltage range, the
"AIR BAG" warning lamp
will
come "ON" solid with no DTCs set. When the engine
is being cranked,
"Ignition 1" voltage is applied from the
"C-1" fuse to the DERM at the "Crank" input. The DERM
responds by grounding the
"SRS" Indicator" output until
"Starter" voltage is removed from the "Crank'' input. This
results in the
"AIR BAG" warning lamp being "ON" during
cranking.After cranking, the DERM
will flash the "AIR
BAG" warning lamp 6 times.
CHART TEST DESCRIPTION
Number(s) below refer to step number(s) on the
diagnostic table.
1. An open "C-22-C-23" fuses would cause the "AIR
BAG" warning lamp to come "ON" steady.
2. A disconnected DERM harness connector will cause
the warning
lamp to come "ON" steady via the
shorting clip from terminal "A1" to terminal "81".
3. This test checks whether the short to ground caused
the
"C-1" fuse to open.
4. This test checks for an open in the ground circuitry
to the DERM.
5. This test determines whether the short to ground is
due to a malfunctioning dual pole arming sensor or
a short
in the wiring.
6. This test checks for an open in the "Ignition 1"
circuitry to the DERM.
7. This test checks for a short from the "SRS Indicator''
circuit to ground.
8. This test checks for a short from the "Crank" input
circuit to 8+.
SRS-1 JOINT CONNECTION TO IGNITION FUSE SRS C·23 10A 1!015 '12 10 IGNITION I IGNITION 1 SWITCH
FUSE~ SRS C-24 10A .... R D
PASS.3eVLR PASS. SOURCE SENSE
PASS SlOE HIGH
PASS SlOE LOW
SERIAL DATA
SRS INDICATOR
..