ESP ISUZU TROOPER 1998 Service Manual Online

6E±130
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1403 (Flash DTC 32)
EGR EVRV Fault
060RW135
Circuit Description
EGR EVRV Circuit has a common power source in
parallel with EGR, VSV, RPCV, and Intake Throttle Motor.
This may cause multiple DTCs. On such occasion, refer
to ªMultiple ECM Information sensor DTCs Setº.
Diagnostic Aids
Check for the following conditions:

Poor connection or damaged EVRV ± Inspect the
wiring harness for damage.

Ensure EVRV is correctly mounted. See
On-Vehicle
Service.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart
3. A malfunctioning MAP sensor can set an EGR DTC.
The MAP sensor could send a constant signal which
is not low enough to set a low MAP DTC. The
constant signal from the MAP sensor also may not
be high enough to set a high MAP DTC. This step
verifies that the MAP sensor is responding.

6E±132
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1404 (Flash DTC 31)
EGR VSV Circuit
060RW135
Circuit Description
The Engine control module (ECM) monitors the EGR
valve input to ensure that the valve responds properly to
commands from the ECM, and to detect a fault if VSV is
stuck open. When the VSV is fixing at closed and opening
the ECM will set DTC P1404.
Diagnostic Aids
Check for the following conditions:

Poor connection or damaged VSV±inspect the wiring
harness for damage.
DTC P1404 ± EGR VSV Circuit

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªONº, engine ªOFFº, review and record
scan tool Failure Records data.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using a scan tool, monitor ªSpecific DTCº info for
DTC P1404 until the DTC P1404 test runs. Note the
result.
Does the scan tool indicates DTC P1404 failed this
ignition?
ÐGo to Step 3
Refer to
Diagnostic
Aids

6E±226
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
0018
Manifold Absolute Pressure (MAP) Sensor
The manifold absolute pressure (MAP) sensor responds
to changes in intake manifold pressure. The MAP sensor
signal voltage to the ECM varies from below 2 volts at idle
(high vacuum) to above 4 volts.
The MAP sensor is used to determine the following:

Boost pressure for injector control.

Barometric pressure (BARO).
If the ECM detects a voltage that is lower than the
possible range of the MAP sensor, DTC P0107 will be set.
A signal voltage higher than the possible range of the
sensor will set DTC P0108. An intermittent low or high
voltage will set DTC P1107 or DTC P1106, respectively.
The ECM can detect a shifted MAP sensor. The ECM
compares the MAP sensor signal to a calculated MAP
based on throttle position and various engine load factors.
If the ECM detects a MAP signal that varies excessively
above or below the calculated value, DTC P0106 will set.
Engine Control Module (ECM)
The engine control module (ECM) is located in the engine
room.
The ECM constantly observes the information from
various sensors. The ECM controls the systems that
affect vehicle performance. The ECM performs the
diagnostic function of the system. It can recognize
operational problems, alert the driver through the MIL
(Service Engine Soon lamp), and store diagnostic trouble
codes (DTCs). DTCs identify the problem areas to aid the
technician in making repairs.
ECM Function
The ECM supplies 5, 12 and 110 volts to power various
sensors or switches. The power is supplied through
resistances in the ECM which are so high in value that a
test light will not light when connected to the circuit. In
some cases, even an ordinary shop voltmeter will not give
an accurate reading because its resistance is too low.
Therefore, a digital voltmeter with at least 10 megohms
input impedance is required to ensure accurate voltage
readings. The ECM controls output circuits such as theinjectors, glow relays, etc., by controlling the ground or
the power feed circuit through transistors or through
either of the following two devices:

Output Driver Module (ODM)

Quad Driver Module (QDM)
ECM Components
The ECM is designed to maintain exhaust emission levels
to government mandated standards while providing
excellent driveability and fuel efficiency. The ECM
monitors numerous engine and vehicle functions via
electronic sensors such as the crankshaft position (CKP)
sensor, and vehicle speed sensor (VSS). The ECM also
controls certain engine operations through the following:

Fuel injector control

Rail pressure control
ECM Voltage Description
The ECM supplies a buffered voltage to various switches
and sensors. It can do this because resistance in the
ECM is so high in value that a test light may not illuminate
when connected to the circuit. An ordinary shop
voltmeter may not give an accurate reading because the
voltmeter input impedance is too low. Use a 10-megohm
input impedance digital voltmeter to assure accurate
voltage readings.
The input/output devices in the ECM include
analog-to-digital converters, signal buffers, counters,
and special drivers. The ECM controls most components
with electronic switches which complete a ground circuit
when turned ªON.º These switches are arranged in
groups of 4 and 7, called either a surface-mounted quad
driver module (QDM), which can independently control up
to 4 output terminals, or QDMs which can independently
control up to 7 outputs. Not all outputs are always used.
ECM Input/Outputs
Inputs ± Operating Conditions Read

Air Conditioning ªONº or ªOFFº

Engine Coolant Temperature

Crankshaft Position

Electronic Ignition

Manifold Absolute Pressure

Battery Voltage

Intake Throttle Position

Vehicle Speed

Fuel Temperature

Oil Temperature

Intake Air Temperature

EGR boost pressure

Oil rail pressure

Camshaft Position

Accelerator position
Outputs ± Systems Controlled

Exhaust Gas Recirculation (EGR)

Injector Control

QWS

ENGINE EXHAUST 6F – 3
ON-VEHICLE SERVICE
FRONT EXHAUST PIPE
Rattles and noise vibrations in the exhaust system are
usually caused by misalignment of parts. When aligning
the system, leave all bolts or nuts loose until all parts
are properly aligned; then tighten, working from front to
rear.
1. Check connections for looseness or damage,
especially for exhaust gas leakage.
2. Check clamps and rubbers for weakness, cracks or
damage.3. If any part of the converter heat shield is damaged
or dented to the extent that it contacts the catalyst,
repair or replace.
4. Check for dents or damage and for any holes or
cracks caused by corrosion.
3
2 1
Legend
(1) Front exhaust pipe
(2) Center exhaust pipe
(3) Mounting rubber
150RW071

7A±27 AUTOMATIC TRANSMISSION (4L30±E)
Changing Transmission Fluid
There is no need to change the transmission fluid unless
the transmission is used under one or more of the
following heavy duty conditions.
A. Repeated short trips
B. Driving on rough roads
C. Driving on dusty roads
D. Towing a trailer
If the vehicle is used under these conditions, change the
fluid every 20,000 miles (32,000 km.)
More over, the remaining life percentage of ATF can be
estimated by using Tech 2 as an auxiliary tool to judge the
right time for ATF replacement.
The remaining life percentage is calculated from ATF'S
heat history. When it is close to 0%, ATF replacement is
recommended.
1. Place a large drain pan under the oil pan.
2. Remove the transmission oil drain screw (2) and drain
fluid.
3. Tighten drain screw (2).
Torque: 38 Nwm (3.9 kg´m/28 lb ft)
4. Remove the transmission overfill screw (1) and fill
transmission through overfill screw opening, using
DEXRON)±III ATF.
NOTE: Add transmission fluid until it flows out over the
overfill screw opening.
5. Let engine idle until a fluid temperature between 32
C
(90
F) and 57
C (135
F) is reached.6. Add transmission fluid until it flows out over the overfill
screw opening, then close the overfill screw (1).
Torque: 38 Nwm (3.9 kg´m/28 lb ft)
NOTE: To prevent fluid leaks, the overfill screw and oil
drain screws gasket must be replaced each time these
screws are removed.
NOTE: C h e c k t r a n s mission fluid temperature with
service scan tool.
242RW003
Selector Lever
Inspection
1. Make sure that when the shifter control lever is shifted
from ªPº to ªLº, a ªclickingº can be felt at each shift
position. Make sure that the gear corresponds to that
of the position plate indicator.
2. Check to see if the shifter lever can be shifted as
shown in illustration.
C07RW009

7A±36
AUTOMATIC TRANSMISSION (4L30±E)
Solenoid (Main Case Valve Body)
Removal
1. Raise the vehicle and support it on jack stands.
2. Disconnect battery ground cable.
3. Remove transfer and exhaust protectors.
4. Drain fluid.
5. Remove exhaust pipe and disconnect oxygen sensor
connector.
6. Support transfer case with a jack and remove third
crossmember.
7. Remove sixteen 10 mm screws, main case oil pan,
magnet, and gasket.
8. Remove three 13 mm screws, oil filter.
9. Disconnect wiring harness from band control
solenoid and shift solenoids. Pull only on connectors,
not on wiring harness.
10. Remove spring pin for shift solenoid A, shift solenoid
B, and band control solenoid respectively, using
suitable pliers taking care not to damage solenoids.
210RW010
244RW003
11. Remove shift solenoid A, shift solenoid B, band
control solenoid, and gaskets from main case valve
body. Do not pull on wiring harness. Remove
solenoids by grasping the metal tip.
Installation
1. Install shift solenoid A, shift solenoid B, band control
solenoid with new gaskets to main case valve body
respectively.
2. Carefully install spring pin with hammer to avoid
damage to valve body, etc.
243RW004
3. Connect wiring harness to solenoids.
4. Install oil filter with a new gasket and the three 13 mm
screws. Tighten the screws to the specified torque.
Torque: 20 Nwm (2.0 kg´m/15 lb ft)
5. Install magnet, main case oil pan with new gasket,
sixteen 10 mm screws. Tighten the screws to the
specified torque.
Torque: 11 Nwm (1.1 kg´m/96 lb in)
6. Install third crossmember and rear mount nuts.
Tighten the nuts and bolts to the specified torque.
Third crossmember bolt: 50 Nwm
(5.1 kg´m/37 lb ft)
Rear mount nut: 50 Nwm (5.1 kg´m/37 lb ft)
7. Install exhaust pipe and connect oxygen sensor
connector. Tighten the bolts to the specified torque.
Exhaust pipe flange bolt torque:
43 Nwm (4.4 kg´m/32 lb ft)
8. Install the transfer and exhaust protectors. Tighten
the bolts to the specified torque.
Torque: 37 Nwm (3.8 kg´m/27 lb ft)
9. Fill transmission through the overfill screw hole of oil
pan, using ATF DEXRON)±III. Refer to Changing
Transmission Fluid in this section.
10. Connect the battery ground cable.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±21
NOTE: To use the DTC again to identify a problem, you
will need to reproduce the fault or the problem. This may
require a new test drive or just turning the ignition on (this
depends on the nature of the fault).
1. IF you have a Tech2:
1. Connect the Tech2 if it is still not connected
GOTHROUGH Tech2 OBD II CONNECTION.
2. Push ªF4º and answer ªYesº to the question ªDo
you really want to clear the codes?º
a. When a malfunction remains as it is the Tech2
displays ª4L30E CODES NOT CLEAREDº. This
means that the problem is still there or that the
recovery was not done. Please GOTO DTC
CHECK.
b. When a malfunction has been repaired and the
recovery is done. The Tech2 displays ª4L30E
CODES CLEAREDº.
2. IF you have no Tech2:
To clear the DTC, remove Fuse ªStop, A/T CONTº
(C±14, 15A) for at least 10 seconds.
DTC Check
1. Diagnostic Trouble Codes (DTC) have been identified
by Tech2.
2. You have written the list of the DTCs. The order of the
malfunctions has no meanings for this PCM. Usually
only one or two malfunctions should be set for a given
problem.
3. Check directly the DTCs you identified. The DTCs are
sorted by number. Refer to Diagnostic Trouble Code
(DTC) Identification in this section.
PCM Precaution
The PCM can be damaged by:
1. Electrostatic discharge
2. The short circuit of some terminals to voltage or to
ground.
Electrostatic Discharge Damage Description:
1. Electronic components used to control systems are
often designed to carry very low voltage, and are very
susceptible to damage caused by electrostatic
discharge. It is possible for less than 100 volts of
static electricity to cause damage to some electronic
components. By comparison, it takes as much as
4,000 volts for a person to even feel the zap of a static
discharge.2. There are several ways for a person to become
statically charged. The most common methods of
charging are by friction and induction. An example of
charging by friction is a person sliding across a car
seat, in which a charge of as much as 25,000 volts
can build up. Charging by induction occurs when a
person with well insulated shoes stands near a highly
charged object and momentarily touches ground.
Charges for the same polarity are drained off, leaving
the person highly charged with the opposite polarity.
Static charges of either type can cause damage,
therefore, it is important to use care when handling
and testing electronic components.
NOTICE: To prevent possible electrostatic
discharge damage:
1. Do not touch the PCM connector pins or soldered
components on the PCM circuit board.
2. Be sure to follow the guidelines listed below if
servicing any of these electronic components:
3. Do not open the replacement part package until it is
time to install the part.
4. Avoid touching electrical terminals of the part.
5. Before removing the part from its package, ground
the package to a known good ground on the vehicle.
6. Always touch a known good ground before handling
the part. This step should be repeated before
installing the part if the part has been handled while
sliding across the seat, while sitting down from a
standing position or while walking some distance.
Information On PCM
1. The Powertrain Control Module (PCM) is located in
the center console and is the control center of the
electronic transmission control system.
2. The PCM must be maintained at a temperature below
185
F (85
C) at all times. This is most essential if the
vehicle is put through a paint baking process. The
PCM will become inoperative if its temperature
exceeds 85
C (185
F). Therefore, it is
recommended that the PCM be removed or that
temporary insulation be placed around the PCM
during the time the vehicle is in a paint oven or other
high temperature process.
3. The PCM is designed to process the various inputs
and then respond by sending the appropriate
electrical signals to control transmission upshift,
downshift, shift feel and torque converter clutch
engagement.
4. The PCM constantly interprets information from the
various sensors, and controls the systems that affect
transmission and vehicle performance. By analyzing
operational problems, the PCM is able to perform a
diagnostic function by displaying DTC(s) and aid the
technician in making repairs.
Intermittent Conditions
If the Tech2 displays a diagnostic trouble code as
intermittent, or if after a test drive a DTC does not
reappear though the detection conditions for this DTC are
present, the problem is most likely a faulty electrical

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±31

Refer to the ªRange Switch Logic Tableº or
ªFunctional Test Procedureº for further information.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
2. This test checks the indicated range signal to the
manual valve actually selected.
5. This test checks for continuity between each
selected range switch connector terminals.Range Switch Logic Table
Range
Range Switch Ping
PositionABCP(G)
ParkONOFFOFFON
ReverseONONOFFOFF
NeutralOFFONOFFON
D4OFFONONOFF
D3ONONONON
2ONOFFONOFF
LOFFOFFONON
IllegalOFFOFFOFFOFF
IllegalOFFOFFOFFON
DTC P0705 Transmission Range Switch (Mode Switch) Illegal Position
StepActionYe sNo
1Perform the following checks:

The transmission linkage from the select lever to the manual
valve is adjusted properly.

Diagnostic circuit check.
Were the checks performed?
Go to Step 2Ð
21. Install the scan tool.
2. With the engine ªoffº, turn the ignition switch ªonº.
NOTE: Before clearing DTC(s), use the scan tool to record ªFailure
Recordsº for reference, as data will be lost when the ªClear Infoº
function is used.
3. Record the DTC ªFailure Recordsº.
4. Select each transmission range: D1, D2, D3, D4, N, R, and P.
Does each selected transmission range match the scan tool
ªRange Switchº display?
Go to Diagnostic
Aids
Go to Step 3
3Are all range switch pin displays incorrect?Go to Step 4Go to Step 5
4Check fuse and wiring to the 8±way connector terminal 5(D) for
opens.
Refer to Mode Switch in Automatic Transmission (4L30±E)
section.
If no problem was found, replace the range switch.
Is the replacement complete?
Go to Step 8Ð
51. Disconnect the 8±way range switch connector.
2. Using ohmmeter, check continuity between terminal 5(D) and
respectively terminals 3(G), 6(C), 7(B) and 8(A) of the 8±way
range switch connector.
3. Move shift selector lever through all positions and compare
results with ªRange Switch Logic Tableº.
Is one range switch pin display incorrect?
Go to Step 6Go to Step 7
6Check the affected wiring and connector, and repair.
Is the repair complete?
Go to Step 8Ð

7A1±34
TRANSMISSION CONTROL SYSTEM (4L30±E)
Diagnostic Aids

Refer to the accompanying chart for the normal range
signals and the illegal combinations.

Inspect the wiring for poor electrical connections at
the PCM and at the transmission 8±way connector.
Look for possible bent, backed out, deformed or
damaged terminals. Check for weak terminal tension
as well. Also check for a chafed wire that could short
to bare metal or other wiring. Inspect for a broken wire
inside the insulation.

When diagnosing for a possible intermittent short or
open condition, move the wiring harness while
observing test equipment for a change.

Refer to the ªRange Switch Logic Tableº or
ªFunctional Test Procedureº for further information.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
2. This test checks the indicated range signal to the
manual valve actually selected.5. This test checks for continuity between each
selected range switch connector terminals.
Range Switch Logic Table
Range
Range Switch Ping
PositionABCP(G)
ParkONOFFOFFON
ReverseONONOFFOFF
NeutralOFFONOFFON
D4OFFONONOFF
D3ONONONON
2ONOFFONOFF
LOFFOFFONON
IllegalOFFOFFOFFOFF
IllegalOFFOFFOFFON
DTC P0706 Transmission Range Switch (Mode Switch) Performance
StepActionYe sNo
1Perform the following checks:

The transmission linkage from the select lever to the manual
valve is adjusted properly.

Diagnostic circuit check.
Were the checks performed?
Go to Step 2Ð
21. Install the scan tool.
2. With the engine ªoffº, turn the ignition switch ªonº.
NOTE: Before clearing DTC(s), use the scan tool to record ªFailure
Recordsº for reference, as data will be lost when the ªClear Infoº
function is used.
3. Record the DTC ªFailure Recordsº.
4. Select each transmission range: D1, D2, D3, D4, N, R, and P.
Does each selected transmission range match the scan tool
ªRange Switchº display?
Go to Diagnostic
Aids
Go to Step 3
3Are all range switch pin displays incorrect?Go to Step 4Go to Step 5
4Check fuse and wiring to the 8±way connector terminal 5(D) for
opens.
Refer to Mode Switch in Automatic Transmission (4L30±E)
section.
If no problem was found, replace the range switch.
Is the replacement complete?
Go to Step 8Ð
51. Disconnect the 8±way range switch connector.
2. Using ohmmeter, check continuity between terminal 5(D) and
respectively terminals 3(G), 6(C), 7(B) and 8(A) of the 8±way
range switch connector.
3. Move shift selector lever through all positions and compare
results with ªRange Switch Logic Tableº.
Is one range switch pin display incorrect?
Go to Step 6Go to Step 7
6Check the affected wiring and connector, and repair.
Is the repair complete?
Go to Step 8Ð

8DÐ4 WIRING SYSTEM
The chassis electrical system is a 12Ðvolt system with a
negative ground polarity.
Wire size are appropriate to respective circuits, and
classified by color. (The classification of harnesses by
color is shown on the circuit diagram for ease of harness
identification.)
The wire size is determined by load capacity and the
length of wire required.
The vehicle harnesses are: body harness, chassis
harness, engine room harness, instrument harness,
transmission harness, engine ECGI harness, dome light
harness, door harness, rear body harness, tailgate
harness, SRS harness and battery cables.
The harnesses are protected either by tape or corrugated
tube, depending on harness location.
The circuit for each system consists of the power source,
wire, fuse, relay, switch, load parts and ground, all of
which are shown on the circuit diagram.
In this section, each electrical device is classified by
system.
For major parts shown on the circuit based on the circuit
diagram for each system, a summary, diagnosis of
troubles and inspection procedures are detailed.
Notes for Working on Electrical
Items
Disconnecting the Battery Cable
1. All switches should be in the ÒOFFÓ position.
2. Disconnect the battery ground cable (2).
3. Disconnect the battery positive cable (1).
CAUTION: It is important that the battery ground
cable be disconnected first. Disconnecting the
battery positive cable first can result in a short circuit.
Connecting the Battery Cable
Follow the disconnecting procedure in the reverse order.CAUTION: Clean the battery terminal and apply a
light coat of grease to prevent terminal corrosion.
Disconnecting the Connector
Some connectors have a tang lock to hold the connectors
together during vehicle operation.
Some tang locks are released by pulling them towards
you (1).
Other tang locks are released by pressing them forward
(2).
Determine which type of tang lock is on the connector
being handled.
Firmly grasp both sides (male and female) of the
connector (3).
Release the tang lock and carefully pull the two halves of
the connector apart.
Never pull on the wires to separate the connectors (4).
2
1
General Description
1
2
3
4