1998 ISUZU TROOPER maintenance schedule

6E±1 ENGINE DRIVEABILITY AND EMISSIONS
ENGINE
ENGINE DRIVEABILITY AND EMISSIONS
CONTENTS
Specifications 6E±5. . . . . . . . . . . . . . . . . . . . . . . . .
Tightening Specifications 6E±5. . . . . . . . . . . . . . .
Vehicle Type Specifications 6E±5. . . . . . . . . . . . .
Diagrams and Schematics 6E±6. . . . . . . . . . . . . . . .
PCM Wiring Diagram (1 of 11) 6E±6. . . . . . . . . . .
PCM Wiring Diagram (2 of 11) For EC,
THAILAND, SOUTH EAST ASIA, LATIN
AMERICA, GULF, SAUDI, CHINA. 6E±7. . . . . .
PCM Wiring Diagram (3 of 11) For SOUTH
AFRICA and EXP. 6E±8. . . . . . . . . . . . . . . . . . . . .
PCM Wiring Diagram (4 of 11) 6E±9. . . . . . . . . . .
PCM Wiring Diagram (5 of 11) 6E±10. . . . . . . . . . .
PCM Wiring Diagram (6 of 11) For
AUSTRALIA, THAILAND, SOUTH EAST
ASIA, LATIN AMERICA, GULF, SAUDI,
LATIN AMERICA. 6E±11. . . . . . . . . . . . . . . . . . . . .
PCM Wiring Diagram (7 of 11) For EC. 6E±12. . .
PCM Wiring Diagram (8 of 11) For EXPORT
and SOUTH AFRICA. 6E±13. . . . . . . . . . . . . . . . .
PCM Wiring Diagram (9 of 11) Except EXP
and SOUTH AFRICA 6E±14. . . . . . . . . . . . . . . . . .
PCM Wiring Diagram (10 of 11) For
EXPORT and SOUTH AFRICA 6E±15. . . . . . . . .
PCM Wiring Diagram (11 of 11) 6E±16. . . . . . . . . .
PCM Pinouts 6E±17. . . . . . . . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 32-Way Red
Connector ± Row ªAº 6E±17. . . . . . . . . . . . . . . . . .
PCM Pinout Table, 32-Way Red
Connector ± Row ªBº 6E±19. . . . . . . . . . . . . . . . . .
PCM Pinout Table, 32-Way White
Connector ± Row ªCº (For EC) 6E±20. . . . . . . . . .
PCM Pinout Table, 32-Way White
Connector ± Row ªCº (For except EC) 6E±21. . .
PCM Pinout Table, 32-Way White
Connector ± Row ªDº
(For except EXPORT and SOUTH
AFRICA) 6E±22. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 32-Way White
Connector ± Row ªDº
(For EXPORT and SOUTH AFRICA) 6E±23. . . . .
PCM Pinout Table, 32-Way Blue
Connector ± Row ªEº
(For except EXPORT and SOUTH
AFRICA) 6E±24. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 32-Way Blue
Connector ± Row ªEº
(For EXPORT and SOUTH AFRICA) 6E±26. . . . .
PCM Pinout Table, 32-Way Blue
Connector ± Row ªFº 6E±27. . . . . . . . . . . . . . . . . .
Component Locators 6E±28. . . . . . . . . . . . . . . . . . . .
Engine Component Locator (This illustration
is based on RHD model.) 6E±28. . . . . . . . . . . . . . Engine Component Locator Table 6E±29. . . . . . . .
Engine Component Locator Table 6E±31. . . . . . . .
Undercarriage Component Locator 6E±32. . . . . .
Undercarriage Component Locator Table
(Automatic Transmission) 6E±32. . . . . . . . . . . . . .
Undercarriage Component Locator Table
(Manual Transmission) 6E±33. . . . . . . . . . . . . . . .
Fuse and Relay Panel (Underhood
Electrical Center) 6E±33. . . . . . . . . . . . . . . . . . . . .
Sensors and Miscellaneous Component
Locators 6E±34. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnosis 6E±37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Strategy-Based Diagnostics 6E±37. . . . . . . . . . . . .
Strategy-Based Diagnostics 6E±37. . . . . . . . . . . . .
DTC Stored 6E±37. . . . . . . . . . . . . . . . . . . . . . . . . . .
No DTC 6E±37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
No Matching Symptom 6E±37. . . . . . . . . . . . . . . . .
Intermittents 6E±37. . . . . . . . . . . . . . . . . . . . . . . . . .
No Trouble Found 6E±37. . . . . . . . . . . . . . . . . . . . .
Verifying Vehicle Repair 6E±37. . . . . . . . . . . . . . . .
General Service Information 6E±38. . . . . . . . . . . . . .
OBD Serviceablity Issues 6E±38. . . . . . . . . . . . . . .
Maintenance Schedule 6E±38. . . . . . . . . . . . . . . . .
Visual / Physical Engine Compartment
Inspection 6E±38. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic Knowledge of Tools Required 6E±38. . . . . .
Serial Data Communications 6E±38. . . . . . . . . . . . . .
Class II Serial Data Communications 6E±38. . . . .
On-Board Diagnostic (OBD) 6E±39. . . . . . . . . . . . . .
On-Board Diagnostic Tests 6E±39. . . . . . . . . . . . .
Comprehensive Component Monitor
Diagnostic Operation 6E±39. . . . . . . . . . . . . . . . . .
Common OBD Terms 6E±40. . . . . . . . . . . . . . . . . .
The Diagnostic Executive 6E±40. . . . . . . . . . . . . . .
DTC Types 6E±41. . . . . . . . . . . . . . . . . . . . . . . . . . .
Verifying Vehicle Repair 6E±42. . . . . . . . . . . . . . . .
Reading Diagnostic Trouble Codes Using
A Tech 2 6E±42. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tech 2 Tech 2 6E±43. . . . . . . . . . . . . . . . . . . . . . . . .
Tech 2 Features 6E±43. . . . . . . . . . . . . . . . . . . . . . .
Getting Started 6E±44. . . . . . . . . . . . . . . . . . . . . . . .
Operating Procedure (For Example) 6E±44. . . . .
DTC Modes 6E±45. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC Information Mode 6E±46. . . . . . . . . . . . . . . . .
Injector Balance Test 6E±46. . . . . . . . . . . . . . . . . . .
EGR Control Test 6E±47. . . . . . . . . . . . . . . . . . . . . .
Idle Air Control System Test 6E±48. . . . . . . . . . . . .

6E±38
ENGINE DRIVEABILITY AND EMISSIONS
General Service Information
OBD Serviceablity Issues
The list of non-vehicle faults that could affect the
performance of the OBD system has been compiled.
These non-vehicle faults vary from environmental
conditions to the quality of fuel used.
The illumination of the MIL (ªCheck Engineº lamp) due to
a non-vehicle fault could lead to misdiagnosis of the
vehicle, increased warranty expense and customer
dissatisfaction. The following list of non-vehicle faults
does not include every possible fault and may not apply
equally to all product lines.
Fuel Quality
Using fuel with the wrong octane rating for your vehicle
may cause driveability problems. Many of the major fuel
companies advertise that using ªpremiumº gasoline will
improve the performance of your vehicle. Most premium
fuels use alcohol to increase the octane rating of the fuel.
Although alcohol-enhanced fuels may raise the octane
rating, the fuel's ability to turn into vapor in cold
temperatures deteriorates. This may affect the starting
ability and cold driveability of the engine.
Low fuel levels can lead to fuel starvation, lean engine
operation, and eventually engine misfire.
Non-OEM Parts
All of the OBD diagnostics have been calibrated to run
with OEM parts. Something as simple as a
high-performance exhaust system that affects exhaust
system back pressure could potentially interfere with the
operation of the EGR valve and thereby turn on the MIL
(ªCheck Engineº lamp). Small leaks in the exhaust
system near the post catalyst oxygen sensor can also
cause the MIL (ªCheck Engineº lamp) to turn on.
Aftermarket electronics, such as cellular phones,
stereos, and anti-theft devices, may radiate EMI into the
control system if they are improperly installed. This may
cause a false sensor reading and turn on the MIL (ªCheck
Engineº lamp).
Environment
Temporary environmental conditions, such as localized
flooding, will have an effect on the vehicle ignition system.
If the ignition system is rain-soaked, it can temporarily
cause engine misfire and turn on the MIL (ªCheck Engineº
lamp).
Poor Vehicle Maintenance
The sensitivity of OBD diagnostics will cause the MIL
(ªCheck Engineº lamp) to turn on if the vehicle is not
maintained properly. Restricted air filters, fuel filters, and
crankcase deposits due to lack of oil changes or improper
oil viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD. Poor vehicle
maintenance can not be classified as a ªnon-vehicle
faultº, but with the sensitivity of OBD diagnostics, vehicle
maintenance schedules must be more closely followed.Related System Faults
Many of the OBD system diagnostics will not run if the
PCM detects a fault on a related system or component.
One example would be that if the PCM detected a Misfire
fault, the diagnostics on the catalytic converter would be
suspended until Misfire fault was repaired. If the Misfire
fault was severe enough, the catalytic converter could be
damaged due to overheating and would never set a
Catalyst DTC until the Misfire fault was repaired and the
Catalyst diagnostic was allowed to run to completion. If
this happens, the customer may have to make two trips to
the dealership in order to repair the vehicle.
Maintenance Schedule
Refer to the Maintenance Schedule.
Visual / Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any diagnostic
procedure or diagnosing the cause of an emission test
failure. This can often lead to repairing a problem without
further steps. Use the following guidelines when
performing a visual/physical inspection:

Inspect all vacuum hoses for punches, cuts,
disconnects, and correct routing.

Inspect hoses that are difficult to see behind other
components.

Inspect all wires in the engine compartment for proper
connections, burned or chafed spots, pinched wires,
contact with sharp edges or contact with hot exhaust
manifolds or pipes.
Basic Knowledge of Tools Required
NOTE: Lack of basic knowledge of this powertrain when
performing diagnostic procedures could result in an
incorrect diagnosis or damage to powertrain
components. Do not attempt to diagnose a powertrain
problem without this basic knowledge.
A basic understanding of hand tools is necessary to effec-
tively use this section of the Service Manual.
Serial Data Communications
Class II Serial Data Communications
This vehicle utilizes the ªClass IIº communication system.
Each bit of information can have one of two lengths: long
or short. This allows vehicle wiring to be reduced by
transmitting and receiving multiple signals over a single
wire. The messages carried on Class II data streams are
also prioritized. If two messages attempt to establish
communications on the data line at the same time, only
the message with higher priority will continue. The device
with the lower priority message must wait. The most
significant result of this regulation is that it provides Tech 2
manufacturers with the capability to access data from any
make or model vehicle that is sold.

6E±347 ENGINE DRIVEABILITY AND EMISSIONS
the secondary ignition circuit to flow through the spark
plug to the ground.
TS24047
Ignition Control PCM Output
The PCM provides a zero volt (actually about 100 mV to
200 mV) or a 5-volt output signal to the ignition control (IC)
module. Each spark plug has its own primary and
secondary coil module (ºcoil-at-plugº) located at the spark
plug itself. When the ignition coil receives the 5-volt signal
from the PCM, it provides a ground path for the B+ supply
to the primary side of the coil-at -plug module. This
energizes the primary coil and creates a magnetic field in
the coil-at-plug module. When the PCM shuts off the
5-volt signal to the ignition control module, the ground
path for the primary coil is broken. The magnetic field
collapses and induces a high voltage secondary impulse
which fires the spark plug and ignites the air/fuel mixture.
The circuit between the PCM and the ignition coil is
monitored for open circuits, shorts to voltage, and shorts
to ground. If the PCM detects one of these events, it will
set one of the following DTCs:

P0351: Ignition coil Fault on Cylinder #1

P0352: Ignition coil Fault on Cylinder #2

P0353: Ignition coil Fault on Cylinder #3

P0354: Ignition coil Fault on Cylinder #4

P0355: Ignition coil Fault on Cylinder #5

P0356: Ignition coil Fault on Cylinder #6
Knock Sensor (KS) PCM Input
The knock sensor (KS) system is comprised of a knock
sensor and the PCM. The PCM monitors the KS signals
to determine when engine detonation occurs. When a
knock sensor detects detonation, the PCM retards the
spark timing to reduce detonation. Timing may also be
retarded because of excessive mechanical engine or
transmission noise.
Powertrain Control Module (PCM)
The PCM is responsible for maintaining proper spark and
fuel injection timing for all driving conditions. To provideoptimum driveability and emissions, the PCM monitors
the input signals from the following components in order
to calculate spark timing:

Engine coolant temperature (ECT) sensor.

Intake air temperature (IAT) sensor.

Mass air flow (MAF) sensor.

PRNDL input from transmission range switch.

Throttle position (TP) sensor.

Vehicle speed sensor (VSS) .

Crankshaft position (CKP) sensor.
Spark Plug
Although worn or dirty spark plugs may give satisfactory
operation at idling speed, they frequency fail at higher
engine speeds. Faulty spark plugs may cause poor fuel
economy, power loss, loss of speed, hard starting and
generally poor engine performance. Follow the
scheduled maintenance service recommendations to
ensure satisfactory spark plug performance. Refer to
Maintenance and Lubrication.
Normal spark plug operation will result in brown to
grayish-tan deposits appearing on the insulator portion of
the spark plug. A small amount of red-brown, yellow, and
white powdery material may also be present on the
insulator tip around the center electrode. These deposits
are normal combustion by-products of fuels and
lubricating oils with additives. Some electrode wear will
also occur. Engines which are not running properly are
often referred to as ªmisfiring.º This means the ignition
spark is not igniting the air/fuel mixture at the proper time.
While other ignition and fuel system causes must also be
considered, possible causes include ignition system
conditions which allow the spark voltage to reach ground
in some other manner than by jumping across the air gap
at the tip of the spark plug, leaving the air/fuel mixture
unburned. Misfiring may also occur when the tip of the
spark plug becomes overheated and ignites the mixture
before the spark jumps. This is referred to as
ªpre-ignition.º
Spark plugs may also misfire due to fouling, excessive
gap, or a cracked or broken insulator. If misfiring occurs
before the recommended replacement interval, locate
and correct the cause.
Carbon fouling of the spark plug is indicated by dry, black
carbon (soot) deposits on the portion of the spark plug in
the cylinder. Excessive idling and slow speeds under
light engine loads can keep the spark plug temperatures
so low that these deposits are not burned off. Very rich
fuel mixtures or poor ignition system output may also be
the cause. Refer to DTC P0172.
Oil fouling of the spark plug is indicated by wet oily
deposits on the portion of the spark plug in the cylinder,
usually with little electrode wear. This may be caused by
oil during break-in of new or newly overhauled engines.
Deposit fouling of the spark plug occurs when the normal
red-brown, yellow or white deposits of combustion by
products become sufficient to cause misfiring. In some
cases, these deposits may melt and form a shiny glaze on
the insulator around the center electrode. If the fouling is
found in only one or two cylinders, valve stem clearances
or intake valve seals may be allowing excess lubricating

6E±25 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
General Service Information
Serviceability Issues
Non-OEM Parts
All of the OBD diagnostics have been calibrated to run
with OEM parts. Accordingly, if commercially sold sensor
or switch is installed, it makes a wrong diagnosis and turn
on the MIL (ªCheck Engineº lamp).
Aftermarket electronics, such as cellular phones,
stereos, and anti-theft devices, may radiate EMI into the
control system if they are improperly installed. This may
cause a false sensor reading and turn on the MIL (ªCheck
Engineº lamp).
Poor Vehicle Maintenance
The sensitivity of OBD diagnostics will cause the MIL
(ªCheck Engineº lamp) to turn on if the vehicle is not
maintained properly. Restricted oil filters, fuel filters, and
crankcase deposits due to lack of oil changes or improper
oil viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD. Poor vehicle
maintenance can not be classified as a ªnon-vehicle
faultº, but with the sensitivity of OBD diagnostics, vehicle
maintenance schedules must be more closely followed.
Related System Faults
Many of the OBD system diagnostics will not run if the
ECM detects a fault on a related system or component.
Visual/Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any diagnostic
procedure or diagnosing the cause of an emission test
failure. This can often lead to repairing a problem without
further steps. Use the following guidelines when
performing a visual/physical inspection:

Inspect all vacuum hoses for punches, cuts,
disconnects, and correct routing.

Inspect hoses that are difficult to see behind other
components.

Inspect all wires in the engine compartment for proper
connections, burned or chafed spots, pinched wires,
contact with sharp edges or contact with hot exhaust
manifolds or pipes.
Basic Knowledge of Tools Required
NOTE: Lack of basic knowledge of this powertrain when
performing diagnostic procedures could result in an
incorrect diagnosis or damage to powertrain
components. Do not attempt to diagnose a powertrain
problem without this basic knowledge.
A basic understanding of hand tools is necessary to effec-
tively use this section of the Service Manual.
Serial Data Communications
Class II Serial Data Communications
This vehicle utilizes the ªClass IIº communication system.
Each bit of information can have one of two lengths: longor short. This allows vehicle wiring to be reduced by
transmitting and receiving multiple signals over a single
wire. The messages carried on Class II data streams are
also prioritized. If two messages attempt to establish
communications on the data line at the same time, only
the message with higher priority will continue. The device
with the lower priority message must wait.
On this vehicle the Tech 2 displays the actual values for
vehicle parameters. It will not be necessary to perform
any conversions from coded values to actual values.
On-Board Diagnostic (OBD)
On-Board Diagnostic Tests
A diagnostic test is a series of steps, the result of which is
a pass or fail reported to the diagnostic executive. When
a diagnostic test reports a pass result, the diagnostic
executive records the following data:

The diagnostic test has been completed since the last
ignition cycle.

The diagnostic test has passed during the current
ignition cycle.

The fault identified by the diagnostic test is not
currently active.
When a diagnostic test reports a fail result, the diagnostic
executive records the following data:

The diagnostic test has been completed since the last
ignition cycle.

The fault identified by the diagnostic test is currently
active.

The fault has been active during this ignition cycle.

The operating conditions at the time of the failure.
Comprehensive Component Monitor
Diagnostic Operation
Comprehensive component monitoring diagnostics are
required to operate engine properly.
Input Components:
Input components are monitored for circuit continuity and
out-of-range values. This includes rationality checking.
Rationality checking refers to indicating a fault when the
signal from a sensor does not seem reasonable. Accel
Position (AP) sensor that indicates high throttle position
at low engine loads or MAP voltage. Input components
may include, but are not limited to the following sensors:

Intake Air Temperature (IAT) Sensor

Crankshaft Position (CKP) Sensor

Intake throttle Position (ITP) Sensor

Engine Coolant Temperature (ECT) Sensor

Camshaft Position (CMP) Sensor

Manifold absolute Pressure (MAP) Sensor

Accel Position Sensor

Fuel Temp Sensor

Rail Pressure Sensor

Oil Temp Sensor

EGR Pressure Sensor

Vehicle Speed Sensor

7A±11 AUTOMATIC TRANSMISSION (4L30±E)
Fluid Condition
FLUID CONDITION
NORMAL*CONTAMINATED
COLORRED OR LIGHT
BROWNBROWNNON±TRANSPAR-
ENT / PINKBROWN
DRAIN RE-
QUIRED?NOYESYESYES
CONTAMINA±
TIONNONEVery small amount of
foreign material in bot-
tom of panContamination by cool-
ant or other sourceLarge pieces of metal
or other foreign materi-
al in bottom of pan
CORRECT
LEVEL AND
CONDITION
1. LOW LEVEL:
A. Add fluid to
obtain proper
level & check for
external leaks.
B. Correct cause of
leak.
2. HIGH LEVEL:
± Remove excess
fluid± Remove both pans
± Change filter
± Flush cooler
± Add new fluid
± Check level± Repair/replace
radiator cooler
± Transmission
overhaul required
± Check for:

Damaged plates
and seals

Contaminated
solenoids
± Flush cooler
± Add new fluid
± Check level± Transmission
overhaul required
± Flush cooler and
cooler lines
± Add new fluid
± Check level
*Fluid should be changed according to maintenance
schedule.
Test Driving
Some 4L30±E automatic transmission complaint will
require a test drive as a part of the diagnostic procedure.
Some codes will not set unless the vehicle is moving. The
purpose of the test drive is to duplicate the customer's
complaint condition and set a current Powertrain Control
Module (PCM) trouble code. Perform this procedure
before each 4L30±E automatic transmission repair, and
again after repairs are made.
IMPORTANT:

Duplicate the condition under which the customer's
complaint was observed.

Depending on the complaint, the line pressure gauge
and the scan tool may be required during the test
drive.

During the test drive, it is important to record all
necessary data from the areas being monitored, for
use in diagnosis. Also listen for and note any unusual
noises.
The following procedure should be used to test drive
4L30±E automatic transmission complaint vehicles:
1. Turn the ignition ON without starting the engine.
Check that the ªCHECK TRANSº lamp comes on for
approximately 2 to 3 seconds and then goes out and
remains out.

If the lamp is flashing, GOTO Check Trans Indicator
in Transmission Control System (4L30±E) section.

If no serial data is present, GOTO OBD System
Check. Refer to Driveability and Emissions in
Engine section.
If the lamp stays ON or stays OFF, GOTO ªCheck
Transº Check in Transmission Control System
(4L30±E) section.
2. Drive the vehicle. During the test drive, be sure that
the transmission achieves normal operating
temperature (approx. 20 minutes).
Allow the transmission to go through all of its gear
ranges, checking shift timing and firmness. Duplicate
the owner's complaint condition as closely as
possible during the test drive.
3. If, during the test drive, the ªCHECK TRANSº lamp
comes on, use the scan tool to check for trouble
codes.
4. If, during the test drive, a problem is felt, but the
ªCHECK TRANSº lamp does not come on and no
trouble codes are present, drive the vehicle with the
PCM disconnected (manually shifting the vehicle).

In Manual L, the vehicle operates in first gear.

In Manual 2, the vehicle operates in third gear.

In Manual 3 or ªDº, the vehicle operates in fourth
gear.
If the problem still exists with the PCM disconnected,
refer to Mechanical/Hydraulic Diagnosis in this
section.
5. If no problem has been found at this point, check all
underhood connections that supply power to the PCM
and ignition fuses. Physically and visually inspect all
the PCM harness connectors for loose or corroded
terminals. Inspect the PCM ground points.