check engine ISUZU TROOPER 1995 Owners Manual

6E2-12 DRIVEABILITY AND EMISSIONS
L-LITER
A metric unit of capacity.
MALFUNCTION
A problem that causes the system to operate
incorrectly. Typical malfunctions are wiring harness
opens
or shorts, failed sensors or circuit components.
MAP-MANIFOLD ABSOLUTE PRESSURE
Air pressure in the intake manifold with reference to
zero or absolute vacuum.
MPH-MILE PER HOUR
A unit measuring speed needed to travel distance of
one mile (5280 feet) in one hour.
MIT -MANUAL TRANSMISSION
N.C.-NORMALLY CLOSED
State of relay contacts or solenoid plunger is close
when voltage is not applied.
N·m-NEWTON METER (Torque)
A metric unit describing force.
N.M.-NORMALLY OPEN
State of relay contacts or solenoid plung&r' is open
when voltage is applied.
NOx-NITROGEN OXIDES
One of the pullutants found in engirie exhaust.
02-0XYGEN (Sensor)
Monitors the oxygen contel)f of the exhaust system
and generates a
voltage signal to the Engine Control
Module (ECM).
OUTPUT
Result of a functi typically controlled by the ECM.
OXYGEN SE OR
Device that etects the amount of oxygen (02) in the
exhaust
stfeam. /
PCV-~OSITIVE CRANKCASE VENTILATION
Prey£nt fumes in crankcase from passing into
atmosphere.
PNP-PARK/NEUTRAL POSITION
PORT-EXHAUST OR INTAKE PORT
PWM-PULSE WIDTH MODULATE
RPM-REVOLUTION PER MINUTE
A measure of rotational speed.
SELF-DIAGNOSTIC TROl)SLE CODE
The ECM can detect malfunctions in the system. If a
malfunction occurs, the ECM turns on the malfunction
indicator lamp. A OTC can be obtained from the ECM
through the malfunction indicator lamp. This DTC will
indicate the area of the malfunction.
TACH-TACHOMETER
TB-THROTTLE BODY
TBI-THROTTLE BODY FUEL INJECTION
Computer Command Control using throttle body fuel
injection
TP SENSOR-THROTTLE POSITION SENSOR
VACUUM
Negative pressure; less than atmospheric pressure.
VIN-VEHICLE IDENTIFICATION NUMBER
VSS-VEHICLE SPEED SENSOR
Sensor which sends vehicle speed information to the
ECM.
VSV-VACUUM SWITCH VALVE
(Electronically Controlled)
VSV-VACUUM SWITCH VALVE
Temperature controlled vacuum switch, that is used to
route or exhaust vacuum at various engine
temperatures.
WOT -WIDE OPEN THROTTLE
DRIVEABILITV AND EMISSION SECTION SUMMARY
The Driveability and Emissions Sections are sub­
divided into three sub sections:
SECTION A: CIRCUIT INFORMATION &
DIAGNOSIS
• Component Locations
• Wiring Diagrams
• ECM Terminal End View and Terminal
Definitions
• On-Board Diagnostic System Check. This
must be the first step of any diagnostic
procedure.
• DTC Charts with facing pages containing
circuit diagrams, circuit operation
information, and
helpful diagnostic
information.
SECTION B: DRIVEABILITY & EMISSIONS
SYMPTONS
• This sub-section assists in diagnosis of
intermittent problems or problems which
don't result in the storing of DTC(s). It is
arranged
by symptoms of poor driveability
and emissions and lists possible causes of
the problems.
SECTION C: COMPONENT CHECKS &
SERVICE
• Component and Circuit Descriptions
• On-Vehicle Service
• Functional
Checks/Diagnostic Charts
•

SECTION II A"
DIAGNOSTIC PROCEDURE SUMMARY
•IGNITION "ON", ENGINE STOPPED. •IS THE MALFUNCTION INDICATOR LAMP "ON"?
•
JUMPER DATA LINK CONNECTOR TERM. 1 TO 3. • DOES MALFUNCTION INDICATOR LAMP FLASH DIAGNOSTIC TROUBLE CODE (DTC) 12?
REFER TO APPLICABLE DTC CHART, START WITH LOWEST DTC.
"SCAN TOOL" SERIAL DATA. REPAIR AS NECESSARY. IF ALL OK, SEE DRIVEABILITY SYMPTOMS IN SECTION B.
Fig. 6E2-2
r
DRIVEABILITY AND EMISSIONS 6E2-13
This is the starting point for the diagnostic procedures.
The diagnostic charts are
related to the Engine Control
Module
(ECM) and will determine if the ECM is working
properly.
This section diagnoses the fuel system controlled by
the
ECM and has charts to diagnosis a circuit when the
ECM has displayed a trouble code.
The
way to approach a problem is to follow some basic
steps.
1.
Are the On-Vehicle Diagnostics working?
We find this out by performing the "On-Board
Diagnostic System Check" Since this is the
starting point
for the diagnostic procedure,
always
begin here.
If the On-Vehicle Diagnostics aren't working, the "On­
Board Diagnostic System Check" will lead you to a
chart in Section
"A" to correct the problem. If the On­
Vehicle
Diagnostics are OK, the next step is:
2.
Is there a Trouble Code stored?
If a trouble code is stored, go directly to the
numbered
DTC chart in Section "A". This will
determine if the fault is still present. If no trouble
code is stored, the third step is:
3. "Scan Tool" Serial Data.
This
involves reading the various pieces of
information available on the Serial Data Stream
with one of the tools available for that purpose.
Information on these tools and the meaning of the
various
displays can be found in the following
paragraphs. Expected readings can be found on
the facing page
for the On-Board Diagnostic
System Check.
This procedure, which takes
only a short time, will help
lead
you to repair the problem in the least amount of
time.

6E2-14 DRIVEABILITY AND EMISSIONS
DATA LINK CONNECTOR ''SCAN TOOLS''
The Engine Control Module (ECM) can communicate a
variety
of information through data link connector
terminal
"2". This data is transmitted at a high frequecy
which requires a
"Scan tool" for interpretation. There
are several
"Scan tools" available for reading this
information.
With an understanding
of the data which the tool
displays, and knowledge of the circuits involved, the
tool can be
very useful in obtaining information which
would be more difficult or impossible to obtain with
other equipment.
"Scan tools" do not make the use of diagnostic charts
unnecessary, nor
can they indicate exactly where a
problem is in a particular circuit. Trouble Tree
Charts
incorporate diagnosis procedures using a "Scan tool"
where possible and most charts require the use of a
"Scan tool" when it is applicable.
A "SCAN TOOL" THAT DISPLAYS FAUL TV
DATA SHOULD NOT BE USED AND THE
PROBLEM SHOULD BE REPORTED TO THE
MANUFACTURER. THE USE OF A FAUL TV
"SCAN TOOL" CAN RESULT IN MIS­
DIAGNOSIS
AND UNNECESSARY PARTS
REPLACEMENT.
ECM's have two (2) modes for transmitting
information. The
following information will describe
the system operation in each
of the modes.
Data List (FO)
On engines that can be monitored in the "Open"
mode, certain parameters can be observed
without changing the engine operating
characteristics. The parameters capable
of being
read vary with engine families.
Most "Scan tools"
are programmed so that the system will go
directly into the data link connector mode
if the
"Open" mode is not available.
''SCAN TOOL'' LIMITATIONS AND USE
The "Scan tool" allows a quick check of sensors
and switches which are inputs
to the ECM. The
"Scan tool" allows one to manipulate wiring
harnesses or components under the hood while
observing the "Scan Tool" readout. This helps in
locating intermittents
with the engine not
running.
INTERMITTENT CONDITIONS
The "Scan tool" is helpful in cases of intermittent
operation. The
tool can be plugged in and
observed while driving the vehicle under the
condition
where the light comes "ON" momen- tarily,
or the
engine driveability is poor
momentarily.
If the problem seems to be related
to certain areas
that can be checked on the "Scan ~
tool", then those are the positions that should be
checked while driving the vehicle. If there does
not seem to
be any correlation between the
problem and any specific circuit, the
"Scan tool"
can be checked on each position, watching for a
period
of time to see if there is any change in the
readings that indicates intermittent operation.
The
"Scan tool" is also a useful and quick way of
comparing operating parameters of a poorly
operating engine with a known good one. For
example; A sensor may shift in
value but not set a
diagnostic trouble code. Comparing with a known
good vehicle may uncover the problem.
The
"Scan tool" has the ability to save time in
diagnosis and prevent the replacement
of good
parts. The key to using the
"Scan tool" success­
fully
for diagnosis lies in the technicians ability to
understand the system he is trying to diagnose as
well as an understanding of the "Scan tool's"
limitations. Therefore, the technician should read
the tool operating manual to become familiar
with
the tool. The following information will describe
most of the "Scan tool" positions and how they
can be helpful in diagnosis.
"SCAN TOOL" POSITIONS
INJECTOR PULSE WIDTH
In this position, the reading is given in milli­
seconds which is the on time that the ECM is
commanding to the injector(s).
CLOSED LOOP/OPEN LOOP
This position will indicate whether the engine
control system
is operating in open or closed
loop. Most systems go closed loop after a certain
amount of run time, when engine coolant
temperature
is high enough, and the oxygen
sensor becomes active.
TROUBLE CODES
Will display any trouble codes stored in the ECM
memory.
THROTTLE POSITION (TP) SENSOR
Values read will be the voltage as seen by the ~
ECM. The voltage should be the TP sensor
specification
with the throttle closed and go up to
about 5 volts with
wide open throttle.
•

THROTTLE ANGLE
Displays in percent the amount the throttle is
open.
HEATED OXYGEN SENSOR (H02S)
The reading will be read out in millivolts (mv) with
a range from 1 to 999 mv. If the reading is
consistently
below 350 (350 mv), the fuel system
is running
lean as seen by the Engine Control
Module
(ECM) and if the reading is consistently
above
550 (550 mv), the system is running rich.
VEHICLE SPEED SENSOR (VSS)
Displays vehicle speed, useful in checking
speedometer accuracy.
PROGRAMMABLE READ ONLY MEMORY
(PROM)
ID
In this position the last4 digits of the Mem-Cal part
number will be displayed.
REVOLUTION PER MINUTE (RPM)
Displays engine speed. Often useful if extra
reference pulses are suspected. A sudden high
revolution per minute indication while at a steady
throttle
would indicate electrical interference
(EMI) in the reference circuit. This interference is
usually caused by ECM wires too close to ignition
secondary wires
or an open electronic ignition
ground circuit.
MILE PER HOUR (MPH)
Displays vehicle speed. Useful in checking
speedometer accuracy.
ENGINE COOLANT TEMPERATURE (ECT)
Displays engine temperature in degress centi­
grade.
After engine is started the temperature
should rise steadily to about
85-95·c, then
stabilize
when the thermostat opens.
INTAKE AIR TEMPERATURE (IAT)
SENSOR
Displays temperature of the intake manifold air.
Should read close to ambient air temperature
when the engine is cold, and rise
as underhood
and engine temperature increases.
DRIVEABILITY AND EMISSIONS 6E2-15
MANIFOLD ABSOLUTE PRESSURE (MAP)
The Manifold Absolute Pressure (MAP) Sensor
produces a low signal voltage when MAP is low
(high vacuum) and a high voltage when the
pressure is high (low vacuum).
With the ignition on and the engine stopped, the
manifold absolute pressure is equal
to
atmospheric pressure and the signal voltage will
be high. This information is used by the ECM as an
indication of vehicle altitude and is referred to as
barometric pressure. Comparison of this
barometric pressure reading
with a known good
vehicle
with the same sensor is a good way to
check accuracy
of a "suspect" sensor. Readings
should be the same
±0.4 Volt.
MAP
Sensors have a colored plastic insert visible
in the connector cavity.
Sensors with the same
insert color are identical in calibration. The
harness electrical connector color should also be
the same
as the sensor insert color.
BAROMETRIC PRESSURE (BARO)
Displays the MAP reading before the engine was
started. This value
will vary depending on
Barometric Pressure and altitude.
EXHAUST GAS RECIRCULATION (EGR)
(ON/OFF)
The exhaust gas recirculation system uses a valve
controlled by vacuum to feed a small amount of
exhaust gas back into the intake manifold to
control formation
of NOx. Like all ECM outputs the
"Scan tool" only indicates that the ECM has
commanded the function and does
not indicate
that the function has
really happened.
SHORT TERM (S.T.) FUEL TRIM AND LONG
TERM (L.T.) FUEL TRIM
On Fuel Injected Engines, normal readings for
these positions are around 128. If higher, it
indicates that the ECM is adding fuel to the base
fuel calculation because the system is lean.
If the
numbers are below 128, the
ECM is taking out fuel
from the base calculation because the system is
rich. The
S.T. Fuel Trim is short term corrective
action while the
L.T. Fuel Trim portion (which is a
long term correction)
will only change if the
intergrator has seen a condition which lasts
for a
calibrated period
of time.

6E2-16 DRIVEABILITV AND EMISSIONS
LONG TERM (LT.) FUEL TRIM
There are from zero to seventeen different cells
which the Engine Control Module (ECM) learns at
depending on revolution per minute (rpm) and
manifold absolute pressure. This parameter
will
display what cell the ECM is using for the fuel
calculation at the time.
IDLE AIR CONTROL (lAC) COUNTS
This system is used to control engine idle speed to
the desired rpm, for different operating
conditions.
In this diagnostic test mode, the
numbers
will indicate what position the ECM
thinks the valve is in. The ECM moves the idle air
control in counts and these counts are displayed
on a
"Scan tool".
DESIRED REVOLUTION PER MINUTE
Indicates the rpm to which the ECM is trying to
control the idle.
AIR CONDITIONING (A/C) REQUEST
Displays the state of the Air Conditioning (A/C)
signal line to the ECM. Should read "YES"
whenever the A/C is requested.
AIR CONDITIONING {A/C) CLUTCH
Displays "ON" when the ECM has commanded
the
A/C Clutch "ON".
POWER STEERING PRESSURE (PSP)
SWITCH
Displays the state of switch. This reading may
vary
with the tool used and the type of switch
installed on the vehicle. The important thing is
that the reading changes state (switches) when
the steering is moved against the stops.
BA TTERV POSITIVE VOLTAGE
Displays the battery positive voltage detected at
the
ECM ignition input.
SPARK ADVANCE
This is a amount of total spark advance including
the base electronic ignition timing.
START UP ENGINE COOLANT
This parameter is the engine coolant temperature
at the
time the engine was started.
ENGINE SPEED (RPM)
RPM calculated during a crank mode, helpful in
diagnosing a NON-start condition.
FUEL TRIM ENABLE
This value is an indication when the Fuel Trim
Enable values are being updated within the ECM
program.
AIR/FUEL RATIO
This is the air to fuel ratio that is being
commanded to the injectors.
INDUCTION AIR CONTROL
The "Scan tool" will display the command being
given to the induction air control
plate system
solenoid.
SECTION B-DRIVEABILITY SYMPTOMS
Always start with Section "A" "On-Board Diagnostic
System Check" before proceeding to the driveability
symptoms.
Section "A" checks the ECM which may
cause the driveability problem. A definition
of each
symptom is included. This will then lead to the most
probable causes of the driveability problem.
SECTION C-COMPONENTS SYSTEMS
There are many component systems that are used to
control fuel and emissions. Section "C" introduces
each component system or control
with a general
description, diagnosis, and on-vehicle service.
Each
of the Section "C" diagnosis sections will contain
information on
how the "Scan tool" can be used for
diagnosing a particular component when a trouble
code has
not been set. (example: Section "C1" under
diagnosis
will explain how the "Scan tool" can be used
for diagnosis as well as what the normal readings
would be for the ECM Sensors.
•

6E2-18 DRIVEABILITV AND EMISSIONS
TOOLS NEEDED TO SERVICE THE SVSJEM
The system requires a data link connector read-out (Scan) tool, tachometer, test light, ohmmeter, digital voltmeter
with 10 megohms impedance (J-39200), vacuum gage and jumper wires for diagnosis. A test light or voltmeter
must be used when specified in the procedures. They must NOT be interchanged. For more complete information
on the operation
of these tools, see the manufacturer's instructions.
Voltmeter
Voltage position measures amount of voltage when
connected in
parallel to an existing circuit. A digital
voltmeter
with 10 megohm input impedance is used
because this type
of meter will not load down the
circuit and
result in faulty readings. Some circuits
require accurate
low voltage readings, and some
circuits in the engine
control module have a very high
resistance.
Digital multimeter: J-39200 or equivalent
Fig. 6E2-4
Ammeter
When used as ammeter, this meter also accurately
measures extremely low current flow. Refer to meter
instructions
for more information.
• Selector must be set properly for both function
and range.
DC is used for most automotive
measurements.
Digital multimeter: J-39200 or equivalent
Ohmmeter
Measures resistance of circuit directly in ohms.
Refer to meter instructions
for more information.
• OL Display in all ranges indicates open circuit.
• Zero display in all ranges indicates a short circuit.
• Intermittent connection in circuit may be
indicated by digital reading that will not stabilize
on circuit.
• Range Switch
200 -Reads ohms
directly
2K, 20K, 200K -Reads ohms in thousands
2M and 20M -Reads ohms in
millions
Digital multimeter:
J-39200 or equivalent
Vacuum pump (20 in. hydragyrum minimum)
Use gage to monitor manifold engine vacuum and the
hand pump to check vacuum sensors,
solenoids and
valves.
Vacuum pump: J-23738
Fig. 6E2-5
Unpowered test light
Used to check wiring for complete circuit and short to
ground
or voltage.
Unpowered test light: J-34142-A
Fig. 6E2-6
•

6E2-20 DRIVEABILITV AND EMISSIONS
Circuit tester
Used to check all relays and solenoids before
connecting them to a
new engine control module.
Measures the circuit resistance and indicates pass or
fail via green or red LED. Amber LED indicates current
polarity. Can also be used as a non-powered continuity
checker.
Engine
control module circuit tester: J-34636
Fig.
6E2-11
Metri-pack terminal remover
Used to remove 150 series Metri-Pack "pull-to-seat"
terminals
from connectors.
Terminal remover: J-35689-A
Fig. 6E2-12
Idler air control (lAC) system driver
Used to test lAC motor for correct functioning and
proper response to commands.
lAC system driver: J-37027-A
Fig. 6E2-13
Weather pack terminal remover
Used to remove Terminals from Weather Pack
connectors.
Weather pack terminal remover: J-28742-A
Fig. 6E2-13
•

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.