check engine ISUZU TROOPER 1995 Workshop Manual

8-24 CHASSIS ELECTRICAL
(Fuse Box)
Fuse No.
Capacity Indication on label Parts (Load)
C-4 10A
ELEC.IGN. Cruise control unit, Rear defogger SW, Rear defogger
relay, Rear
defo9ger SW indicator light, Clutch SW
(M{T), Transmission SW-1, 2 (M!T), Transmission
SW-3, 4 (M{T), Cancel
SW (Combination SW), Cruise
control main
SW, Cruise control main relay, Cruise
control indicator light, Cruise control
SW, Door mirror,
Door mirror defogger SW, AfT shift lock control unit,
Power window relay, Electronic brake control module,
Transmission control module, G sensor, Upshift-2
relay, Upshift indicator (Meter)
C-5 15A FRTWIPER &WASHER
Windshield wipt~r and washer SW, Windshield wiper
motor, Windshit~ld washer motor, Windshield wiper
intermittent relay
C-6 10A RR WIPER & WASHER
Rear wiper & washer SW, Rear washer motor, Rear
wiper motor, Rear wiper intermittent relay
C-7 10A (H/LAMP WIPER) Headlight wiper SW, Headlight wiper motor, Headlight
washer motor, Headlight
wiper timer
C-8 15A ENGINE Generator, ECM main relay, V.S.V; EGA, V.S.V: canister,
V.S.V: intake air
(DOHC)
C-9 15A IGN. COIL Ignition control module, Engine control module
C-10 10A METER GAUGE Vehicle speed stmsor, Remind Buzzer, Meter and
gauge
(Voltmeter, Engine coolant temperature gauge,
Tachometer, Speedometer,
Oil pressure gauge, Fuel
gauge),
Indicator and warning light (Anti-lock brake
system, Rear wheel anti-lock, Seat belt, check engine,
Low fuel, 4WD,
Oil pressure, Upshift, Brake system,
Charge,
AfT oil temp, Cruise control indicator light,
Check trans indicator light,
Power drive indicator
light,
Winter drive indicator light), 4WD SW, Parking
brake SW, Seat belt SW, Brake differential SW
Electronic brake control module, Engine control
module, Rear wheel anti-lock brake controller
C-11 10A (AUDIO[ACCJ) MIRROR Audio, Door mirror, Door mirror control SW, Door
mirror folding SW, Digital clock, Speaker
C-12 20A CIGARETTE Cigarette lighter
C-13 10A
ANTI THEFT Anti-theft controller
C-14 15A
STOP AfT CONT Stoplight SW (w/o cruise control), Brake SW (w/cruise
control), Rear wheel anti-lock brake controller,
Stoplight, Transmission control module, Electronic
brake control module, Trailer harness connector,
Cruise control unit,
AfT shift lock control unit, Lockup
off relay
C-15
20A (AUDIO[B]) Horn,
Horn relay, Horn SW, Hazard warning light SW,
Flasher unit, Anti-theft horn, Hazard warning light,
Audio
•

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

8-44 CHASSIS ELECTRICAL
B REMOVAL (FIG. 8-60)
Preparation: Disconnect the battery ground cable.
5. Starter switch
Fig. 8-60
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.
B INSTALLATION
To install, follow the removal steps in the everse
order noting the
following point.
1. 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. 8-61)
Starter switch
harness
Fig. 8-61
CLUTCH START SWITCH
cowl
When the clutch pedal is depressed, the clute start
switch is turned on
to form a circuit to activ e the
starter.
~ INSPECTION
1 til!. I Check the continuity between the clute start
switch terminals. (Fig. 8-62)
Replace the switch when the result
of insp ction
is found abnormal.

'

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.

.~·-
, ca· CIO I O'l O'l
ENGINE
COOLANT TEMPERATURE SENSOR
VSV:
INTAKE
AIR~""-"-,
FUEL
~,
'"-
E-22
INJECTOR
No.5
'~~
FUEL
~
"':·.E-23
INJECTOR
No.3
"-
'"<
FUEL
"-
·,,,
E-~
4 /'
INJECTOR
No.'1'~-
1~4 "...

.......
. .......
' '
/
BODY
ASM
"-..'-
>
DIS / / E-18
ICM !POWER)
THROTILE '
E-~5·.-..,
.. '-, ·,/
r
E-2~,,
/E-5v~~;>o~~
--vsv:EGR
FUEL
INJECTOR
No.6
E-11
~E-10 ~FUEL
INJECTOR
No.4
E-27-+
"'
:1
~
.........
_
'-......
"·INTAKE
AIR TEMPERATURE SENSOR
ECM EGR EVAP
lAC
ICM MAP TP vsv )
X
·"
~
FUEL
INJECTOR
No.2
VSV: EVAP CANISTER
E28
E29
RESISTOR:UPSHIFT-M/T

CRANKSHAFT
POSITION
SENSOR
MAP
SENSOR RELAY:UPSHIFT-M/T ,
ENGINE
CONTROL
MODULE
EXHAUST GAS RECIRCULATION
EVAPORATIVE EMISSION IDLE
AIR CONTROL
IGNITION CONTROL
MODULE
MANIFOLD ABSOLUTE PRESSURE
THROTILE POSITION VACUUM
SWITCHING
VALVE
DIODE-AfT
'...,
RELAY:
ECM
MAIN
~"'-.,'...,
RELAY:FUEL
PUMP
'....
'
RELAY
& FUSE BOX
(FL-1,FL-2,FL-3,F-2,F-10)
BATIERY~
H-41 H-42~
KNOCK SENSOR
MODULE
)
DATA
LINK
CONNECTOR
VEHICLE
SPEED
SENSOR
(METER)
MALFUNCTION INDICATOR LIGHT (CHECK ENGINE) UPSHIFT INDICATOR LIGHT
(METER)-M/T
STARTER
SW
·~FUEL
PUMP
EVAP CANISTER
)
~
co I
~
~ co
(/)
0
r-
:::t
0
)> C/)
0
C/)
~
Cii
-
m
0
r-m
2
0
I
~
c
:a
0
0 )>
J:
r-
0

!! (Q
(
FUEL INJECTOR
No.1
/
FUEL INJECTOR
No.5
FUEL INJECTOR
No.3
I
\/.
ICM
CPOWERl
_/
E-27
cp
I
CRANKSHAFT
~
POSITION SENSOR
ECM
: ENGINE
CONTROL
MODULE
EGR
:EXHAUST
GAS
RECIRCULATION
lAC
: IDLE
AIR
CONTROL
ICM
: IGNmON
CONTROL
MODULE
MAP
: MAN
I FORD
ABSOLUTE
PRESSURE
VSV
:VACUUM
SWITCHING
VALVE
(
VSV:EGR I VSV:
EVAPORATIVE
EMISSION
CANISTER
THROTTLE
POSmON
SENSOR
~FUEL
INJECTOR
No.6
FUEL
INJECTOR
No.4
FUEL
INJECTOR
No.2
ICMCCRl ICMCCONTl
RESISTOR:UPSHIFT-MIT RELAY:UPSHIFT-1-MIT
DIODECAITl
RELAY:
ECM
MAIN
RELAY:FUEL
PUMP
RELAY
& FUSE
BOX
CFL-1,FL-2,FL-3,F-2,F-10l
H-41 H-42
POWER
STEERING
PRESSURE
SW.
H-33
VEHICLE
SPEED
SENSOR (METER) MALFUNCTION INDICATOR
LIGHT
(CHECK
ENGINE)
UPSHIFT
INDICATOR
LIGHT
CMETERl-MfT
(
/STARTER
SW.
F-4
/
DATA
LINK
I
d .
'v_AR__
FUEL
PUMP
CONNECTOR~
!P
~;~·
/~
,,
1-9
~ ~ r-0 n ~ 0 2 • en 0 X n
(") ::::1: )> CJ)
CJ) Cii m r­m ~ :D ~ r-01) I fD

8-56 CHASSIS ElECTRICAl
STARTER SWITCH NOTE:
Refer
to START AND CHARGING in this section. For relay
removal, refer to "Connector H ndling" ~
under "NOTES FOR WORKING ON ELE TRICAL .,..........
DATA LINK CONNECTOR ITEMS" in this section.
The data
link connector (white) is used to retrieve the
diagnostic
trouble codes stored from the engine UPSHIFT-1 RELAY
control module. The data link connector is installed at .----------------+----.
inside of the instrument panel driver lower cover.
(Fig. 8-72)
Fig. 8-72
FUEL PUMP RELAY
ENGINE CONTROL MODULE MAIN
RELAY
,-------,
"" __!.___./, ' 4 '<)I ~
~! Q)__l__1__j" ' L _____ _j
Fig. 8-73
~ INSPECTION
Check to see if there is any continuity between
the
relay terminals. (Fig. 8-73)
Replace the relay when the result of inspection
is found
abnormal.
®-@ · · · · · · · · No continuity
(When battery voltage is applied between CD-@)
®-@ · · · · · · · · Continuity
m
:
Fig. 8-74
~ INSPECTION
ltgl Check to see if there is any continuity b tween
the
relay terminals. (Fig. 8-7 4)
Replace the relay when the result of ins ~
is found abnormal.
DIODE
Terminal No. 4 3
Connection A (±) 8
pattern 8 8 (±)
Fig.
8-75
..

8-74 CHASSIS ELECTRICAL
FOG LIGHT SWITCH
~ INSPECTION
I tgj Check the continuity between the connector ter­
minals
while operating the switch. (Fig. 8-94)
Replace the switch when the result of inspection
is found abnormal.
ru~
IT
2 [II
161514131
c-
Fig. 8-94
B REMOVAL (FIG. 8-95)
TI ';
Preparation: Disconnect the battery ground cable.
Fig.
8-95
I I 1. Front console I assembly
1. Front console assembly
• Remove four screws.
• Remove the transmission shift leve knob
(M!r only).
• Remove the transfer shift lever knob.
• Disconnect the seat heater switch con ectors
(If so equipped).
• Disconnect the POWER & WINTER switch
connectors
(A/T only).
2.
Lower cluster assembly
• Remove three screws.
• Disconnect the cigar lighter connector .
• Remove the cigar lighter illuminatio bulb
socket.
• Disconnect the ashtray illuminatio bulb
connector.
3.
Instrument panel driver lower cover
• Remove the engine hood opener.
• Remove three screws and clip.
• Disconnect four fasteners.
4.
Instrument panel cluster assembly
• Remove five screws.
• Disconnect the four clips at top of instr ment
panel cluster assembly.
5. Fog
light switch
• To remove the switch, pushing the loc from
the back side of the cluster assembly.
B INSTALLATION
To install, follow the removal steps in the r verse
order, noting the
following point:
1. Push in the switch with your fingers un il the
switch is locked securely.
LIGHTING RELAY
~ INSPECTION
Check to see if there is any continuity be ween
the relay terminals. (Fig.
8-96)
Replace the relay when the result of in spec ion is
found abnormal.
CD-3 · · · · • · · · No continuit
(When the battery voltage is applied
between
4 -s)
•

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.
•

8-198 CHASSIS ELECTRICAL
ENGINE CONTROL MODULE MAIN
RELAY
~ INSPECTION
1~1 Check to see if there is any continuity between
the relay terminals. (fig. 8-242)
Replace the relay when
the result of inspection
is
found abnormal.
®-@ ....... No continuity
(When battery voltage is applied between
G) and@)
®-@ ....... Continuity
Fig. 8-242
NOTE:
r-----~
®__1__/ o---!-@
I I CD I :
ill! ~ ' L _____ .J
For the relay removal, refer to "Connector Handling"
in the "NOTES FOR WORKING ON ELECTRICAL
ITEMS"
in this section.
•