engine ISUZU TROOPER 1995 Workshop Manual

DRIVEABILITY AND EMISSIONS 6E2-21
Engine control module connector terminal remover Intake manifold diagnostic plate
Used to remove terminal from Micro-Pack connectors.
Engine
control module connector terminal remover: J-
33095
Used to fuel rail pressure test and fuel injector balance
test.
Fig. 6E2-14
Intake manifold diagnostic plate: J-39185
GROUND BOLT
€3 EXHAUST GAS RECIRCULATION (EGR) EXHAUST MANIFOLD PLATE
INTAKE BOLT SPACER
Fig. 6E2-14
GENERAL SPECIFICATIONS
"S''
Many of the specifications used in this section are located on the Vehicle Emission Control Information Label
under the hood.
Listed on the chart
below are locations of specifications used in this Section.
Specification Location of information
Engine Timing
Not adjustable, engine control module controls timing.
Idle Speed Not adjustable, engine control module controls idle.
Spark Plug Type See "Identification" in Section OA.
Spark Plug Gap Vehicle Emission Control Information Label.
Engine Diagnostic Trouble 8th digit of VIN number. See "Maintenance Service Data" in Section 08.
Code
Part Numbers of Major AIPDN (American lsuzu Parts Dept. Network)
Components
Replacement of Vehicle ISUZU Parts Catalog.
Emission Control
Information Label
AIPDN
(American lsuzu Parts Dept. Network)

DRIVEABILITY AND EMISSIONS 6E2-23
SECTION A
ENGINE COMPONENTS/WIRING DIAGRAMS/DIAGNOSTIC
CHARTS
CONTENTS
On-Board Diagnostic (OBD} System Check . 6E2-23
Basic Procedure . . . . . . . . . . . . . . . . . . . . . 6E2-23
Engine Component Location . . . . . . . . . . 6E2-24
Engine Control Module Wiring
Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . 6E2-26
Engine Control Module (ECM) Connector
Identification . . . . . . . . . . . . . . . . . . . . . 6E2-33
"SCAN TOOL" On-Board Diagnostic (OBD)
System Check . . . . . . . . . . . . . . . . . . . . 6E2-34
On-Board Diagnostic (OBD} System Check . 6E2-36
Won't Flash Diagnostic Trouble Code
(DTC)
12 No "Check Engine" Malfunction
Indicator Lamp (MIL)-Chart A-1 . . . . . . 6E2-38
No Data Link Connector (DLC) Data or
Won't Flash Diagnostic Trouble Code
(DTC)
21 "Check Engine" Malfunction
Indicator Lamp (MIL} "On" Steady-
Chart A-2 . . . . . . . . . . . . . . . . . . . . . . . . . 6E2-40
Engine Crank But Will Not
Run-Chart A-3 . . . . . . . . . . . . . . . . . . . . . 6E2:.....42
Fuel Pump Relay Circuit-Chart A-5 . . . . . 6E2-48
Fuel System Pressure Test-Chart A-7 ..• /6E2-50
Intake Manifold Diagnostic Plate Chart/
A-8 ......................... ,-:· . . . 6E2-56
Diagnostic Trouble Code (DTC~13 /
Heated Oxygen Sensor (H02 Circuit
(Open Grounded Circuit) . . . . . . . . . . . 6E2-58
Diagnostic Trouble Code (D'JiC) 14A
Engine Coolant Temperaiure (ECT}
Sensor Circuit (High -:remperature
Indicated) ....... /. . . . . . . . . . . . . . . . 6E2-60
Diagnostic Trouble P'ode (DTC} 14B
Engine
Coolan·vremperature (ECT)
Sensor Circuit'(Low Temperature
Indicated) ./. . . . . . . . . . . . . . . . . . . . . . . 6E2-62
Diagnostic Jtouble Code (DTC) 21A
Throtti~,.Position (TP) Sensor
Circu)t (Signal Voltage High) . . . . . . . . 6E2-64
Diag.,Ostic Trouble Code (DTC) 21B
Jflrottle Position (TP} Sensor
//Circuit (Signal Voltage Low} ........ 6E2-66
ON-BOARD DIAGNOSTIC (OBD) SYSTEM
CHECK
The "On-Board Diagnostic System Check" verifies the
system is functioning correctly.
Some special
considerations
to keep in mind while making the "On­
Board Diagnostic System Check" are:
Diagnostic Trouble Code (DTC(23A
Intake Air Temperature (IAT)
Sensor Circuit (low Temperature
Indicated) ......................... 6E2-68
Diagnostic Trouble Code (DTC) 23B
Intake Air Temperature (IAT)
Sensor Circuit (High Temperature
Indicated) ... / ...................... 6E2-70
Diagnostic T[ouble Code (DTC} 24
Vehicle )!Peed Sensor (VSS} Circuit ... 6E2-72
DiagnostiC Trouble Code (DTC) 32
Exh,tist Gas Recirculation (EGR}
Cir,.Cuit ............................ 6E2-74
Dia,gnostic Trouble Code (DTC} 33A
·Manifold Absolute Pressure (MAP)
Sensor Circuit (Signal Voltage
High-Low Vacuum) ................. 6E2-76
Diagnostic Trouble Code (DTC) 33B
Manifold Absolute Pressure (MAP}
Sensor Circuit (Signal Voltage
Low-High Vacuum) ................. 6E2-78
Diagnostic Trouble Code (DTC) 42
Ignition Control (IC) Circuit . . . . . . . . . . 6E2-80
Diagnostic Trouble Code (DTC} 43
Knock Sensor (KS} Circuit (DOHC) .... 6E2-82
Diagnostic Trouble Code (DTC) 44
Heated Oxygen Sensor (H02S} Circuit
(Lean Heated Oxygen Sensor (H02S)
Signal Indicated} . . . . . . . . . . . . . . . . . . . 6E2-84
Diagnostic Trouble Code (DTC) 45
Heated Oxygen Sensor (H02S) Circuit
(Rich Heated Oxygen Sensor (H02S)
Signal Indicated) . . . . . . . . . . . . . . . . . . . 6E2-86
Diagnostic Trouble Code (DTC) 51
Engine Control Module (ECM} Failure
ECM Failed
or Electrically Erasable
Programmable Read Memory Only
Failure} ........................... 6E2-88
Blocking Drive Wheels
The vehicle drive wheels should always be
blocked
while checking the system.
BASIC PROCEDURE
If the basic information on using the diagnostic
procedures contained in this section has
not been
reviewed, refer
to the introduction of this section.

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