ignition ISUZU TROOPER 1995 Workshop Manual

6E2-24 DRIVEABILITY AND EMISSIONS
ENGINE COMPONENT LOCATION (SOHC)
UNDERHOOD
FUSE/RELAY
CENTER
8 A
T
T
E
R y
0 COMPUTER HARNESS
C1 Engine control module (ECM) *
C2 DLC diagnostic connector
C3 "Check Engine" Malfunction
indicator lamp
C4 Engine harness connectors (3)
C5 ECM harness ground
C6 Fuse panel
C7 Electronic ignition ground
CS ECM main relay
C9 Fuel pump fuse 15A
C11 Oxygen 1 OA heater fuse
C12 30A ECM main fusible link
0 ECM CONTROLLED
COMPONENTS
1 Fuel injector
2 Idle air control
3 Fuel pump relay
6 Ignition control module
6a Ignition coils
12 Exhaust gas recirculation
(EGR) VSV
13 Air conditioning relay
14 Evaporate emission canister
purge VSV
Fig. 6E2-15
Q ECM INFORMATION
SENSORS
®
A Manifold Absolute Pressure
B Heated oxygen sensor
C Throttle position sensor
D Engine
coolant temperature
E Intake air temperature -
sensor
F Vehicle speed sensor
K Power steering pressure
switch (in-line)
@ EGRVALVE
@CHASSIS GROUNDS
* The ECM is located behind the
console in the lower dash.
®
[::::J EMISSION COMPONENTS
(NOT
ECM CONTROLLED)
N1 Crankcase vent valve (PCV)
N2 EGR valve back pressure
transducer
N3 Spark plugs
N4 Fuel rail test fitting (for fuel
pressure test)
N5 Crankshaft position sensor
N15 Fuel vapor canister

DRIVEABILITY AND EMISSIONS 6E2-25
ENGINE COMPONENT LOCATION (DOHC)
®B
UNDERHOOD FUSE/RELAY CENTER
B A T
T
E
A y
0 COMPUTER HARNESS
C1 Engine control module (ECM)
C2 DLC diagnostic connector
C3 "Check Engine" Malfunction
indicator lamp
C5 ECM harness ground
C6 Fuse panel
C8 ECM main relay
C9 Fuel pump fuse 15A
C10 Injector resistor
C11 Oxygen 1 OA heater fuse
C12
30A ECM main fusible link
0 ECM CONTROLLED
COMPONENTS
1 Fuel injector
2 Idle air control
3 Fuel pump relay
6 Ignition control module
ignition control
6a Ignition coils
7 Knock sensor Module under
charcoal canister
12
Exhaust Gas Recirculation
(EGR) VSV
*
®®
Fig. 6E2-16
13 Air conditioning relay
14 Evaporate emission canister
purge VSV
15 Induction air control plate
system VSV
Q ECM INFORMATION
SENSORS
A Manifold Absolute Pressure
B Heated oxygen sensor
c Throttle position sensor
D Engine
coolant temperature
F Vehicle speed sensor
H Crankshaft
position sensor
J Knock sensor
(under intake
assembly)
K Power steering pressure
switch (in-line)
L Intake air temperature
@ EGRVALVE
@ CHASSIS GROUNDS
f----1 EMISSION COMPONENTS !.-----' (NOT ECM CONTROLLED)
N1 Crankcase vent valve (PCV)
N2 Exhaust gas
recirculation valve
back pressure transducer
N3 Spark plugs
N4 Fuel rail test fitting (for fuel
pressure test)
N15 Fuel vapor canister
* The ECM is located behind the
console in the lower dash.

6E2-26 DRIVEABILITV AND EMISSIONS
ENGINE CONTROL MODULE WIRING DIAGRAM (1) (SOHC}
To ignition
switch 10 A
Meter fuse Underhood
connectors
located driver's side
shock tower
"Check Engine" MALFUNCTION
.-----------..:.:.1 N.:.:D:..:.IC=A~T~O:..:.R.:....=:.LA..::.M.:..::P:..___-,--___.:O:..:.R.:.:.N::.._IY.....:E:..:L=----1 c4
.------~~----~~O:..:R:..:N/~8~L=-=K--~ C 2
TCM
(C91-C8)
Engine Control Module(ECM)
"Check
engine" light control
DLC Diagnostic Request Input
Serial
data inpuVoutput
.--------f---+-....::...::;_;__=---_-1 A 12 System ground
Common
Data Link Connector (White) Chamber L.....::.=::....=..:=-=----+---1 C12 System ground
Intake air
temperature sensor
Throttle position
sensor
Manifold absolute pressure sensor
Engine
Coolant Temperature sensor Heated
oxygen
J-,.:..:W:.:..H.:..:T.:.:I8:..:L:.:U:......__ __ ....-To Fuel
RED/BLU (M/T)
1---=-'L T'-.!8~L:!:U'--l(.::::A/T!....!...!....) ---< f------lt+-~!,!..._'H---1 83
BRN/8LK
84
8RN/WHT 85
BRN/RED 87
8RN!YEL
BS
1---------~~~B~L~U~/8~L~K~--I 07
BLK/WHT
TCM
(C91-C6)
BLK/WHT 1------------4>---< t-----=~:..:.:..:_.:..:_ ....... -1 02
1-----------~ f----'-=-'-==--....-1 06
1-----------~ f--.-::..:=.=.:....=..c~-+--1 A 1
BLU/ORN
H02S Signal Input
H02S Ground
lAC coil "A" HI
lAC coil "A" LO
lAC coil "B" HI
lAC coil "B" LO
IAC=IDLE AIR CONTROL
Intake
Air Temperature(IAT)
signal input
Sensor ground
TPS signal input
5 volt reference
MAP
signal input
1---------'----...._.G:=.:..:.RY-=--------1 A 11 Sensor ground
1-------;---.:::G:..:R_;_YI:...::8:..:L::..:K:__---I 012 Engine Coolant Temperature
signal input
Fig. 6E2-17
•

DRIVEABILITY AND EMISSIONS 6E2-27
ENGINE CONTROL MODULE WIRING DIAGRAM (2) (SOHC)
Located in underhood Engine Control
Module(ECM) Underhood connectors
To B+ relay fuse center located driver's side
/r BLK r----------s-ho-c-1-:-t-ow_:_::...:~.:..:K!Wc..:...:..:H:...:T.:..__---I C3 Fuel pump relay control
30A
Fusible
link
15A I F/P 1 Fuel pump BLK/ORG ~~
02 sensor heater 1 1 0 -2 sensor -10A 1 heater Fuel pump
BLK/YEL
relay Located in underhood relay fuse
center
B+ ------1
I
REO/WHT t---.-----t--:..:.::::..=.!...:...:..:..:...:_.:..._--1 B 1 Battery feed
REO/WHT
'-----t--..:.:..::-=:!....:c.:.:...:.-=-------1 C16 Battery feed
TCM BRN (C91-014) -_.:..._--=..:..:..:...:----1 A9 Engine Coolant Temperature signal output (A/T only)
L----~-----------~~-.:..:R.:::EO~/~G~R~N_:_--IA6 Ignition
voltage signal input
Engine
fuse 15A
To
ignition switch BLK/YEL
=
REO/GRN
REO/GRN
REO/GRN
REO/GRN
REO/GRN
REO/GRN
REO/GRN
ORG/BLU 016
ORG/BLU 015
L:...:..::..:-=---.....-:..:.:....:...!._{ L_B::..:L:..:U:c..IW:..:..:...:.HT_:__--l c " 14
BLK/BLU C15
,--.----<.._.:::B.:::LKI=B.::.LU=---1 01
GRN/YEL GRN/YEL
~--~~~~--~~~~--~C6
Power steering Mode SW--+*-f--=-8=-LU~/.:..P.:..:N~K:___---l pressure switch (A/T) C7
Fig. 6E2-18
1 and 2 fuel injector
3 and 4 fuel injector
5 and 6 fuel injector
ECM Ground
ECM Ground
EGR VSV control
Canister purge VSV
control
PSP Switch signal input
P/N signal

6E2-28 DRIVEABILITV AND EMISSIONS
ENGINE CONTROL MODULE WIRING DIAGRAM (3) (SOHC)
Ignition Control
Module Underhood
connector
located driver's side
1 shock tower I I 1:-2~--~~--~B~L~K~--~
- : To -4-
-BRN 1. r--TACH.
A-4 ~ TCM IC91-D12) -I
I
YELLOW
·~ YEL!GRN \ VEL/RED YEL!BLK
I--­B-1IB-2IB-3l C-1
l
1 2
Crankshaft Position Sensor Inductive pickup
sensor I
I
I
I
Thermo cut-out I
I
I
I
I
n I
Mo\\I•Silj ~~
To Transmission SW ~ r-------------------~ -
'---<
LT GRN To SW: fan
Thermo cut-out relay'
GRN/
WHT
....--+-----~

BRN
High
pressure switch
BRN
NC compressor relay
BRN GRY/RED
Located in underhood relay center passenger
compartment
BRN r::-1
I
I
r I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
GRN/ORN
GRY!YEL To
TCM IC91-D8)
GRN
n
l
I I 1 NC compressor 10A ~ToB+ NCfuse
Diode E-4
I clutch I
I
' ' '
Fig. 6E2-19
A4
C9
A2
~
ENGINE CONTROL MODULE (ECM)
Reference HI
Reference LO
Shift light (MfT)
NC request signal input
NC clutch relay control
..

DRIVEABILITY AND EMISSIONS 6E2-29
ENGINE CONTROL MODULE WIRING DIAGRAM (1) (DOHC)
Underhood connectors
located driver's side
shock
tower
To ignition
switch 7.5AMP ,.... ~ ®
I
I
Meter fuse I "Check Engine" I Malfunction I Indicator Lamp I
I
'
I 8LK/8LU I
D
I l TCM (C91-C8) 1
~ 1 2 ~ ~ co.;;mo~~ : ata Link Connector (White) Chamber 1 0 Common1 Chamber 1 Heated oxygen -= I
rg
=F
leair s ontrol C] alve
ld c v
M
te anifold
air
mperature sensor
Throttle position sensor
Manifold absolute pressure sensor
Engine
Coolant
T emperature
Sensor
sensor I
I
-A/IN-1:'1 WHT/8LU I
~ RED/8LU (M/TI I
~ ""21 L T 8LU (A/TI II ....::....1 ,1,
8LK/GRN :,
I
I
I
I
cam l:
I
I
Au A )I y"-\1 r--
8 8LK/WHT I I
I
I
I
8 ~ 1--II
~ r£ \ 'I A ,1,
8LU/ORN I
r£ ~ I
8 ~ f--I A I
I
I
_A& a A I y"-I r--I 8 I
I
I
Fig. 6E2-20
VLT
ORNNEL
ORN/8LK
8LK/8LU
I 8LK/8LU
To Fuel
pump relay
( ) RED ( v v
8LU
~ -8RN/8LK
8RN/WHT
8RN/RED
8RNNEL
8LU/8LK
TCM (C91-C6)
8LK/WHT !
RED/8LU
8LU/ORN
TCtM
(C91-C5)
GRY/RED
GRY
GRY/8LK Engine
Control
Module (ECMI
.-----
AS "Check engine" light control
C4 DLC Diagnostic Request lnpu
C2 Serial data input/output
A12 System ground
C12 System ground
83
H02S Signal input
82 H02S ground
84
lAC coil "A" HI
85 lAC coil "A" LO
87 lAC coil "8" HI
86 lAC coil "8" LO
lAC = Idle Air Control
D7 MAT signal input
D2 Sensor ground
D6 TPS signal input
A1 5 volt reference
D9 MAP signal input
A11 Sensor ground
D12 Engine Coolant Temperatur e signal input
......__

6E2-30 DRIVEABILITY AND EMISSIONS
ENGINE CONTROL MODULE WIRING DIAGRAM (2) (DOHC)
Located in underhood Engine Control Module(ECM)
T B relay
fuse center Underhood connectors
o + located
driver's side r--. / shock tower
/ I BLK.---+-I_: ~==-----------+-: __ O_R_N...:./W_H_T_--1 C3 Fuel pump relay control
Fusible
= tti F10 15A 1
30A
I' k I 1 Fuel pump In REO/WHT BLK/ORG Fu:.._pu~
~ ~-T 02 sensor heater :
0 _ ~ I ~ 2 sensor -<. Fuel pump ~ lh @ relay Located in F2 10A 1 eater
a:'---underhood
relay fuse I
BLK 30A
1 B+ _..;c:..::ec:..:n-=.:te:.:..r_-1 REO/WHT B1 Battery
feed
Fusible link
lL---,--1 _ _:.:R:.=E-==O'-'fW:..:..:....:H-=-T---i C16 Battery feed Main relay
BLK/YEL I
I
I
I
I
I
I
L---~--------------<)1 REO/GRN ,1, A6
Engine ') CB fuse 15A
To ignition switch
REO/GRN No. 1
BLU/YEL I
REO/GRN No.2 BLU/YEL : ORG/ ORG/BLU 016
015
REO/GRN No.3 BLU/GRN
BLU/YEL }1 BLU l ORG/BLU L....::-=-=.:...=.:._.._ __ -<
REO/GRN No.4
BLU/GRN \'
REO/GRN No. 5
BLU/WHT
REO/GRN No. 6 BLU/WHT I
I
External1 resistor 1 I
1.4 n
t-+--B_L-'U/_G_R_N--1 C
14
1.3Q
'---=B:..::L:..::U_:_IY;_:E:.:L~ C 11 BLK/YEL Intake air VSV I
I
l
I I t.__-1~-----< t--...:...W:..:.H.:....:.T.:...::/B:..::Lc::.U_-1 A
3
I
I
I
EGRVSV
'---111 ____ -<' (-_...:...W.:....:.H.:....:.T.:...c/G=-R_N_-1 AB

Canister VSV 1
I 1
/ WHT/REO I '---1~-----<,f--,--"------1 A7 ~------~ I I I I
~r---G~RN~/Y~E_L __ 1 __ G~R_N...:.!Y_EL_~ C 6
Fender
LH Power steering
pressure switch Canister purge VSV
control
Fig. 6E2-21
Ignition voltage signal input
Injector drivers
Injector drivers
Injector drivers
Injector drivers
Intake air VSV
control
EGR VSV control
Evaporative Emission Canister
Purge VSV control
PSP Switch signal input
1111

DRIVEABILITV AND EMISSIONS 6E2-31
ENGINE CONTROL MODULE WIRING DIAGRAM (3) (DOHC)
Thermo cut-out Module Ignition
Control
Module
J
Underhood connector located driver's side 1 shock tower I
~r---~: ___ B~L=K~--~
I-: To -d::-1--­A-4 I-
BRN I, r--TACH. \~TCM I (C91-D12) I
~1-----\(. f-------...:.Y.=.E:::LL:.:O:..:W:..:._--1 OS
~L-----'~ A-21-----< f----_.:Y:..::E:.::LJ!..:.R:.::E~D----1 B9 f.---\' A-
11---\-{' t----Y:..::E~LJ:..:::B.:::LK~--l BB f.---I BLK/ I f.---ORN 15A To C-1 "\~ ignition
Engine switch
fuse
2
Inductive pickup
sensor
Crankshaft
Position Sensor
NC switch
I ~~ l '--------J
\'r-----.
High
BRN
BRN
]_OA ~ ToB+ A/C fuse
BRN
NC compressor relay
GRY/RED
Located in underhood relay center passenger compartment
BRN I I I "' I
Diode E-4
I
I
-<( ,1,
I
I
GRN/ORN
GRY!YEL
To
TCM (C91-D8l
GRN
n
l
NC compressor clutch
' '
Fig. 6E2-22
C9
A2
ENGINE CONTROL MODULE (ECM)
Ignition Control output
Bypass control
Reference HI
Reference LO
NC request signal input
NC clutch relay control

DRIVEABILITY AND EMISSIONS 6E2-33
ENGINE CONTROL MODULE (ECM) CONNECTOR IDENTIFICATION
This engine control module voltage chart is for use with a digital voltmeter to further aid in diagnosis. The voltages
you get may vary due to low battery charge or other reasons, but they should be very close.
The following conditions must be before testing:
• Engine at operating temperature • "Scan tool" not installed
•
Engine idling in "Close Loop" (for "Engine Run"
column) •
All voltages showing "Battery Position Voltage
(8+)" indicates battery or charging voltage
•
DLC Diagnostic terminal not grounded
VOLTAGE VOLTAGE
DC CIRCUIT PIN WIRE
KEY ENG. COLOR
"ON" RUN
DC CIRCUIT PIN WIRE
KEY ENG. COLOR "ON" RUN
ID 5.0V 5.0V THROTILE
POSITION ~TP~ SENSOR & MANIFOLD ABSOLUT P ESSURE A1 BLU/ORN 8+ B+ BATIERY FEED B1 RED/WHT
5 VOLT REFERENCE B+"ON" B+ OFF AIR CONDITIONING CLUTCH RELAY A2 GRY/YEL 0 "OFF" 0* ON
CONTROL o• o• OXYGEN SIGNAL GROUND 82 BLU
B+ s+ INTAKE
AIR VACUUM SWITCH VALVE A3 WHT/BLU (VSV) CONTROL
o• O*® SHIFT INDICATOR LAMP DRIVER A4 ORN/BLU .430MV
VALlES OXYGEN
SIGNAL INPUT
B3 RED
NOT NOT
IDLE AIR CONTROL (lAC) COIL "A" HI B4 8RN/BLK USABLE
USABLE
o• B+ "CHECK ENGINE" MALFUNCTION A5 VLT INDICATOR LAMP CONTROL
B+ B+ IGNITION VOLTAGE SIGNAL INPUT
AS RED/GRN
NOT NOT
lAC COIL "A" LO B5 8RN/WHT USABLE USABLE
NOT NOT
lAC COIL
"B" LO B6 BRN/YEL USABLE
USABLE
B+ B+ EVAPORATE EMISSION CANISTER PURGE A7 WHT/RED VSVCONTROL NOT
NOT
lAC COIL "B" HI B7 BRN/RED USABLE
USABLE
B+ 8~ EXHAUST GAS RECIRCULATION AS WHT/GRN VSV CONTROL
@VAR VAR TRANS TP SENSOR SIGNAL OUTPUT A9 8RN
o• o• ELECTRONIC IGNITION REFERENCE LO 88 YEL/BLK
o• 1.1V-ELECTRONIC
IGNITION REFERENCE HI B9 YEL/RED
2.4V
NOT USED B10
NOT USED
A10
NOT USED
B11 o• o• SENSOR GROUND A11 GRY
NOT USED B12 GRY/BLU o• o• SYSTEM
GROUND A12 8LK/PNK
VOLTAGE
VOLTAGE
DC CIRCUIT PIN WIRE
KEY ENG. COLOR DC CIRCUIT PIN WIRE
KEY ENG. COLOR "ON" RUN "ON" RUN
NOT USED C1 o• o• SYSTEM GROUND D1 BLK/BLU
4.7V 4.7V
SERIAL DATA INPUT/OUTPUT C2 ORN/8LK o• 0* SENSOR GROUND D2 BLK/WHT
@) B+ B+ FUEL PUMP RELAY CONTROL C3 PNK/WHT NOT USED D3
B+ B+ DLC DIAGNOSTIC REQUEST INPUT C4 ORN/YEL NOT USED D4
NOT USED C5 o• .1·.2V IGNITION
CONTROL OUTPUT D5 YEL
@B+ B+ POWER STEERING PRESSURE SWITCH C6 GRN/YEL SIGNAL INPUT 0.54V VAR
TP SENSOR
SIGNAL INPUT D6 BLU/RED
@O* o• PARK/NEUTRAL POSITION
INPUT C7 BLU/PNK VAR
VAR INTAKE AIR TEMPERATURE SIGNAL D7 BLU/BLK INPUT D7 BLU/BLK
NOT USED CB ® ® VEHICLE SPEED SENSOR
SIGNAL INPUT D8 WHT/BLK
B+"ON" 0 "ON" AIR CONDITIONING REQUEST SIGNAL C9 GRN/ORN
0 "OFF" B+"OFF"
INPUT 4.7V 1-2V MANIFOLD ABSOLUTE PRESSURE D9 GRY/RED SIGNAL
INPUT
NOT USED
C10 8-10V
VAR K.S.
MODULE INPUT D10 LTGRN/WHT
B+ B+ FUEL INJECTOR
DRIVER C11 BLU/YEL o• 4.9V IGNITION CONTROL BYPASS CONTROL D11 YELIGRN
o• o• SYSTEM GROUND
C12 BLK/PNK VAR VAR ENGINE COOLANT TEMPERATURE
D12 GRY/BLK SIGNAL
INPUT
NOT USED
C13 NOT USED D13
B+ 8+
FUEL INJECTOR DRIVER C14 BLU/GRN NOT USED D14
o• o• SYSTEM GROUND
C15 BLK/BLU B+ B+ FUEL INJECTOR DRIVER D15 ORN/BLU
8+ B+ BATIERY FEED C16 RED/WHT B+ 8+
FUEL INJECTOR DRIVER D16 ORN/8LU
* All voltages shown "0" should read less than .5 volts.
Reads battery positive voltage for 2 seconds after ignition "ON" then should read 0 volts. CD
®
® @
B+ with shifter in gear and clutch pedal not depressed.
B+ to 0 volts depending on Position of drive wheels
B+ for 2 seconds.
@
®
0 Volt with steering wheel cramped.
A/T Vehicles only

6E2-34 DRIVEABILITY AND EMISSIONS
''SCAN TOOL" ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK
The Diagnostic Circuit is an organized approach to identifying a problem created by an electronic engine control
system malfunction. It must be the starting point for any drive ability complaint diagnosis, because it directs the
service technician to the next
logical step in diagnosing the complaint.
The "Scan tool" data listed in the table may be used for comparison, after completing the on-board diagnostic
system check and finding the on-board diagnostics functioning
properly with no trouble codes displayed. The
"Typical Data Values" are an average of display values recorded from normally operating vehicles and are
intended
to represent what a normally functioning system would typically display.
A "SCAN tool" that displays faulty data should not be used, and the problem should be reported to the
manufacturer. The use of a faulty "SCAN tool" can result in misdiagnosis and unnecessary parts
replacement.
Only the parameters listed below are used in this manual for diagnosis. If a "Scan tool" reads other parameters,
the
values are not recommended for use in diagnosis. For more description on the values and use of the "Scan
tool" to diagnosis engine control module inputs, refer to the applicable component diagnosis section in
"Component System", Section "6E2-C". If all values are within the range illustrated, refer to "Symptoms", Section
"6E2-B".
"SCAN TOOL" DATA
Test under following condition.
Idle I Upper radiator hose hot I Closed throttle I Park or neutral I "Closed Loop" I All Accessories "OFF"
"SCAN TOOL" position Units displayed Typical data value
Engine Speed RPM ± 50 RPM from desired RPM in drive (A/T) ± 100 RPM from desired rpm in neutral (MIT)
Desired
RPM RPM Engine control module idle command (varies with Engine load and temperature)
ENG COOL TEMP
Degrees Celsius/Fahrenheit 85-105 (185-221)
Intake Air Temperature (IAT) Degrees Celsius/Fahrenheit 10-90 (50-199) (varies with Underhood
temperature and sensor location)
Manifold Absolute Pressure Volts 1 - 2 (varies with manifold and barometric pressure)
Barometric Pressure Volts Varies depending on altitude
Throttle Position Volts .50-1.25
Throttle Angle 0-100% 0 at Idle
BPW (base pulse width) Milliseconds 0.0 to 499.9
Oxygen Sensor Volts Volts .1 - 1 (varies continuously)
S.T. Fuel
Trim Counts 108-154
LT. Fuel Trim Counts 116-145
Loop Status
Open/Closed "Closed Loop"
Fuel Trim Cell 0/1 1
Spark Advance Degrees Varies continuously
Ignition Control Enable No/Yes Yes
Knock Retard
Degrees
0-45
Shift Light OFF/ON OFF
Idle Air Control
Counts (steps) 1 -50 depending on engine load
PARK/NEUTRAL P-N and R-D-L Park/Neutral (AUTO)
A/C Request Switch Yes/No No
A/C Request ON/OFF "OFF"
Vehicle Speed
Mile per hour/KPH 0
Power Steering
NORMAL/HI PRESSURE NORMAL
EGR Solenoid
ON/OFF OFF
AIR Control Solenoid
ON/OFF OFF
Induction Air Solenoid OFF/ON OFF ("ON" above 5000 RPM)
Air Fuel Ratio Ratio 0-25.5:1
EVAP Purge OFF/ON OFF
Idle Throttle No/Yes Yes
Fuel Trim Enable No/Yes Yes
System Voltage Volts 13-15
PROM ID 000 0-65535
Time From Start 00:00