1998 ISUZU TROOPER electrical system

6E±227 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS

QOS

Diagnostics
± Malfunction Indicator Lamp (Service Engine
Soon lamp)
± Data Link Connector (DLC)
± Data Output
ECM Service Precautions
The ECM is designed to withstand normal current draws
associated with vehicle operation. Avoid overloading any
circuit. When testing for opens and shorts, do not ground
or apply voltage to any of the ECM's circuits unless
instructed to do so. These circuits should only be tested
using digital voltmeter. The ECM should remain
connected to the ECM or to a recommended breakout
box.
Intake Throttle Position (ITP) Sensor
ITP sensor is a potentiometer type and installed to the
intake throttle valve body. A voltage of 5V is applied
constantly from ECM to ITP sensor thereby to determine
by change in voltage the opening of the intake throttle
valve during warming up.
Transmission Range Switch
IMPORTANT:The vehicle should not be driven with the
transmission range switch disconnected; idle quality will
be affected.
The four inputs from the transmission range switch
indicate to the ECM which position is selected by the
transmission selector lever.
For more information on the transmission on the
transmission range switch, refer to
Automatic
Transmission
.
Accelerator Position Sensor (AP)
AP sensor is a potentiometer type and installed to
accelerator pedal bracket. A voltage of 5V constantly
applied from ECM to the sensor thereby to determine the
accelerator pedaling angle by change in voltage. Further,
this sensor is provided with an accelerator switch, which
is set off only when the accelerator pedal is stepped on.
Aftermarket Electrical and Vacuum
Equipment
Aftermarket (add-on) electrical and vacuum equipment is
defined as any equipment which connects to the vehicle's
electrical or vacuum systems that is installed on a vehicle
after it leaves the factory. No allowances have been
made in the vehicle design for this type of equipment.
NOTE: No add-on vacuum equipment should be added
to this vehicle.
NOTE: A d d - o n e l e c t r i c a l equipment must only be
connected to the vehicle's electrical system at the battery
(power and ground).
Add-on electrical equipment, even when installed to
these guidelines, may still cause the powertrain system to
malfunction. This may also include equipment not
connected to the vehicle electrical system such asportable telephones and radios. Therefore, the first step
in diagnosing any powertrain problem is to eliminate all
aftermarket electrical equipment from the vehicle. After
this is done, if the problem still exists, it may be diagnosed
in the normal manner.
Electrostatic Discharge Damage
Electronic components used in the ECM are often
designed to carry very low voltage. Electronic
components are susceptible to damage caused by
electrostatic discharge. Less than 100 volts of static
electricity can cause damage to some electronic
components. By comparison, it takes as much as 4000
volts for a person to feel even the zap of a static
discharge.
TS23793
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 vehicle seat.

Charge by induction occurs when a person with well
insulated shoes stands near a highly charged object
and momentary touches ground. Charges of the
same polarity are drained off leaving the person
highly charged with the opposite polarity. Static
charges can cause damage, therefore it is important
to use care when handling and testing electronic
components.
NOTE: To p r e ve n t p ossible electrostatic discharge
damage, follow these guidelines:

Do not touch the ECM connector pins or soldered
components on the ECM circuit board.

Do not open the replacement part package until the
part is ready to be installed.

Before removing the part from the package, ground
the package to a known good ground on the vehicle.

If the part has been handled while sliding across the
seat, while sitting down from a standing position, or
while walking a distance, touch a known good ground
before installing the part.

6E±228
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
General Description (Air Induction)
Air Induction System
The air induction system filters contaminants from the
outside air, and directs the progress of the air as it is
drawn into the engine. A remote-mounted air cleaner
prevents dirt and debris in the air from entering the
engine. The air duct assembly routes filtered air to the
throttle body. Air enters the engine by to following steps:
1. Through the throttle body.
2. Into the intake manifold.
3. Through the cylinder head intake ports.
4. Into the cylinders.
General Description (Fuel Metering)
Deceleration Mode
The ECM reduces the amount of fuel injected when it
detects a decrease in the Accelerator position.
Fuel Injector
Fuel injector comprises the solenoid, hydraulic line, and
fuel line. Fuel injection is controlled by the continuity time
signal and continuity start timing signal from ECM to the
solenoid
ECM determines the running conditions of engine by
input signals such as engine speed. Accelerator throttle
valve opening, and engine coolant temperature, thereby
to send the solenoid the best suited signal to the engine
status. When current is carried to the solenoid, the
armature opens the poppet valve to alow high pressure oil
to run into the injector. Under the pressure of the oil, the
piston and plunger are depressed to compress the fuel in
the combustion chamber of the plunger. Specifically, the
pressure of the fuel compressed is increased by a piston
top/ plunger bottom area ratio over the pressure of high
pressure oil, thereby lifting the fuel nozzle end needle for
injecting fuel.
Fuel Metering System Components
The fuel metering system is made up of the following
parts:

The fuel injectors.

The intake throttle body.

The Accelerator position (AP) sensor

The ECM.

The crankshaft position (CKP) sensor.

The camshaft position (CMP) sensor.
Basic System Operation
Fuel is supplied through fuel filter to the fuel pump.
The fuel pump is installed to the oil pump, and fuel is
forced, through the fuel pump outlet, pipe and cylinder
head inside, into the fuel injector.
An orifice is provided at the rear fuel outlet of cylinder
head to control the pressure of oil.The injector is controlled by ECM which gives
opening/closing commands to the solenoid installed on
the top of the injector. Opening/closing operation of the
pressurized engine oil circuit of the injector controls fuel
injection quantity, fuel injection timing, etc.
A/C Clutch Diagnosis
A/C Request Signal
This signal tells the ECM when the A/C mode is selected
at the A/C control head. The ECM uses this to adjust the
idle speed.
Refer to
A/C Clutch Circuit Diagnosis for A/C wiring
diagrams and diagnosis for A/C electrical system.
General Description Exhaust Gas
Recirculation (EGR) System
EGR Purpose
The exhaust gas recirculation (EGR) system is use to
reduce emission levels of oxides of nitrogen (NOx). NOx
emission levels are caused by a high combustion
temperature. The EGR system lowers the NOx emission
levels by decreasing the combustion temperature.
The ECM uses information from the following sensors to
control EGR valve boost pressure.

ECT

ITP

Engine Speed

AP sensor

7A±5 AUTOMATIC TRANSMISSION (4L30±E)
Normal Operation Of 1998 4L30±E
Transmission
Torque Converter Clutch (TCC)
Application Conditions:
The TCC is normally applied in 2nd, 3rd and 4th gears
only when all of the following conditions exist:
Ð The engine coolant temperature is above 70
C
(158
F).
Ð The brake pedal is released.
Ð The shift pattern requests TCC apply.
Moreover, TCC is always applied in 2nd, 3rd and 4th
gears when the transmission oil temperature is above
135
C (275
F).
This mode should be canceled at 125
C (257
F).
ATF Warning Lamp
The ATF warning lamp will be constantly on (not flashing)
if the transmission oil temperature is above 140
C
(284
F).
The ATF warning lamp goes off again when the
transmission oil temperature is below 130
C (266
F).
Special Shift Pattern When The Engine Is
Cold:
A special shift pattern is activated when the engine
coolant temperature is below 70
C (158
F). (3±4 shifts,
for example, are delayed for small throttle openings and
will occur a few MPH higher.)
Diagnosis
Introduction
The systematic troubleshooting information covered by
this Section offers a practical and systematic approach to
diagnosing 4L30±E transmission, using information that
can be obtained from road tests, electrical diagnosis, oil
pressure checks or noise evaluation.
The key to correcting a complaint is to make use of all of
the available symptoms and logically letting them direct
you to the cause.
When dealing with automatic transmission complaints, it
is best to gather as many symptoms as possible before
making the decision to remove the transmission from the
vehicle.
Frequently, the correction of the complaint does not
require removal of the transmission from the vehicle.
Driver Information
To analyze the problem fill out a complete description of
the owner's complaint.
Please draw a circle around the right information and
complete the following form. (The next page is an
example of a completed form). You can draw a circle
around many numbers if you are not sure.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±1
TRANSMISSION
TRANSMISSION CONTROL SYSTEM (4L30±E)
CONTENTS
Service Precaution 7A1±2. . . . . . . . . . . . . . . . . . . . . .
General Description 7A1±2. . . . . . . . . . . . . . . . . . . . .
Shift Control 7A1±6. . . . . . . . . . . . . . . . . . . . . . . . . .
Band Apply Control 7A1±6. . . . . . . . . . . . . . . . . . . .
Torque Converter Clutch Control 7A1±6. . . . . . . . .
Line Pressure Control 7A1±6. . . . . . . . . . . . . . . . . .
On±Board Diagnostic System 7A1±6. . . . . . . . . . .
Fail Safe Mechanism 7A1±6. . . . . . . . . . . . . . . . . . .
Torque Management Control 7A1±6. . . . . . . . . . . .
ATF Warning Control 7A1±6. . . . . . . . . . . . . . . . . . .
ABS Control (If equipped) 7A1±6. . . . . . . . . . . . . .
Winter Drive Mode 7A1±9. . . . . . . . . . . . . . . . . . . . .
Backup Mode 7A1±9. . . . . . . . . . . . . . . . . . . . . . . . .
Functions of Input / Output Components 7A1±10. .
Diagnosis 7A1±11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Check Trans Indicator 7A1±11. . . . . . . . . . . . . . . . . .
Diagnostic Check 7A1±11. . . . . . . . . . . . . . . . . . . . . .
ªCheck Transº Check 7A1±12. . . . . . . . . . . . . . . . . .
Tech2 OBD II Connection 7A1±13. . . . . . . . . . . . . . .
OBD II Diagnostic Management System 7A1±18. .
16 ± Terminal Data Link Connector (DLC) 7A1±19.
Malfunction Indicator Lamp (MIL) 7A1±20. . . . . . . .
Types Of Diagnostic Trouble Codes
(DTCs) 7A1±20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clear DTC 7A1±20. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC Check 7A1±21. . . . . . . . . . . . . . . . . . . . . . . . . . .
PCM Precaution 7A1±21. . . . . . . . . . . . . . . . . . . . . . .
Information On PCM 7A1±21. . . . . . . . . . . . . . . . . . .
Intermittent Conditions 7A1±21. . . . . . . . . . . . . . . . .
Transmission And PCM Identification 7A1±22. . . . .
Diagnostic Trouble Code (DTC)
Identification 7A1±24. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0218 Transmission Fluid Over
Temperature 7A1±25. . . . . . . . . . . . . . . . . . . . . . . . . . . Conditions For Setting The DTC 7A1±25. . . . . . . . .
Action Taken When The DTC Sets 7A1±25. . . . . . .
Conditions For Clearing The DTC 7A1±25. . . . . . . .
Diagnostic Aids 7A1±25. . . . . . . . . . . . . . . . . . . . . . . .
Test Description 7A1±25. . . . . . . . . . . . . . . . . . . . . . .
DTC P0560 System Voltage Malfunction 7A1±27. . .
DTC P0705 Transmission Range Switch
(Mode Switch) Illegal Position 7A1±30. . . . . . . . . . . .
DTC P0706 Transmission Range Switch
(Mode Switch) Performance 7A1±33. . . . . . . . . . . . . .
DTC P0712 Transmission Fluid Temperature
(TFT) Sensor Circuit Low Input 7A1±36. . . . . . . . . . .
DTC P0713 Transmission Fluid Temperature
(TFT) Sensor Circuit High Input 7A1±39. . . . . . . . . . .
DTC P0719 TCC Brake Switch Circuit High
(Stuck On) 7A1±42. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0722 Transmission Output Speed
Sensor (OSS) Low Input 7A1±45. . . . . . . . . . . . . . . . .
DTC P0723 Transmission Output Speed
Sensor (OSS) Intermittent 7A1±48. . . . . . . . . . . . . . .
DTC P0730 Transmission Incorrect
Gear Ratio 7A1±51. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0748 Pressure Control Solenoid
(PCS) (Force Motor) Circuit Electrical 7A1±54. . . . .
DTC P0753 Shift Solenoid A Electrical 7A1±56. . . . .
DTC P0758 Shift Solenoid B Electrical 7A1±59. . . . .
DTC P1790 ROM Transmission Side Bad
Check Sum 7A1±63. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1792 EEPROM Transmission Side
Bad Check Sum 7A1±64. . . . . . . . . . . . . . . . . . . . . . . .
DTC P1835 Kickdown Switch Always On 7A1±65. . .
DTC P1850 Brake Band Apply Solenoid
Malfunction 7A1±67. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1860 TCC Solenoid Electrical 7A1±71. . . . . . .

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

7A1±22
TRANSMISSION CONTROL SYSTEM (4L30±E)
connection or loose wiring. Terminals and grounds should
always be the prime suspect. Intermittents rarely occur
inside sophisticated electronic components such as the
PCM.
Use the DTC information to understand which wires and
sensors are involved.
When an intermittent problem is encountered, check
suspect circuits for:
1. Poor terminal to wire connection.
2. Terminals not fully seated in the connector body
(backed out).
3. Improperly formed or damaged terminals.
4. Loose, dirty, or corroded ground connections:
HINT: Any time you have an intermittent in more than
one circuit, check whether the circuits share a
common ground connection.
5. Pinched or damaged wires.
6. Electro±Magnetic Interference (EMI):
HINT: Check that all wires are properly routed away
from spark plug wires, distributor wires, coil, and
generator. Also check for improperly installed
electrical options, such as lights, 2±way radios, etc.Use the F3 SNAPSHOT mode of the Tech2 to help isolate
the cause of an intermittent fault. The snapshot mode will
record information before and after the problem occurs.
Set the snapshot to ªtriggerº on the suspect DTC. If you
notice the reported symptom during the test drive, trigger
the snapshot manually.
After the snapshot has been triggered, command the
Tech2 to play back the flow of data recorded from each of
the various sensors. Signs of an intermittent fault in a
sensor circuit are sudden unexplainable jump in data
values out of the normal range.
Transmission And PCM Identification
The chart below contains a list of all important information
concerning rear axle ratio, Powertrain Control Module
(PCM), and transmission identification.
VEHICLE
Rr axlePCMTRANSMISSION
TypeEngine
Rr axle
RatioISUZU Parts No.Calibration
CodeIsuzu Part No.Model Code
Isuzu /
Trooper3.2L V64.555
8±16254±949±0
8±16254±749±0
8±16253±989±0
G208±96018±272±3FP (4X4)

7A1±24
TRANSMISSION CONTROL SYSTEM (4L30±E)
Diagnostic Trouble Code (DTC)
Identification
DTC NUM-
BERDTC NAMEDTC TYPEªCHECK
TRANSº
P0218Transmission Fluid Over TemperatureD
P0560System Voltage MalfunctionCFlash
P0705Transmission Range Switch (Mode Switch) Illegal PositionD
P0706Transmission Range Switch (Mode Switch) PerformanceD
P0712Transmission Fluid Temperature Sensor Circuit Low Input
(TFT)D
P0713Transmission Fluid Temperature (TFT) Sensor Circuit High
InputD
P0719TCC Brake Switch Circuit High (Stuck ON)D
P0722Transmission Output Speed Sensor (OSS) Low InputCFlash
P0723Transmission Output Speed Sensor (OSS) IntermittentCFlash
P0730Transmission Incorrect Gear Ratio FlashCFlash
P0748Pressure Control Solenoid (PCS) (FORCE MOTOR) Circuit
ElectricalCFlash
P0753Shift Solenoid A ElectricalCFlash
P0758Shift Solenoid B ElectricalCFlash
P1790ROM Transmission Side Bad Check SumCFlash
P1792EEPROM Transmission Side Bad Check SumCFlash
P1835Kickdown Switch Always OND
P1850Brake Band Apply Solenoid MalfunctionD
P1860TCC Solenoid ElectricalD
DTC TYPEDEFINITION
CFlashing Check Trans on 1st failure
DNo lamps
NOTE: On the following charts, refer to the Powertrain
Control Module (PCM) section for the Wiring System, and
the Body and Accessories section for circuit diagram
details, parts location, and connector configuration.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±25
DTC P0218 Transmission Fluid Over Temperature
D07RW029
Circuit Description
The Transmission Fluid Temperature (TFT) sensor is a
thermister that controls the signal voltage to the PCM.
The PCM supplies a 5±volt reference to the sensor on
circuit RED/BLK±GRN/RED. When the transmission fluid
is cold, the sensor resistance is high and the PCM will
sense high signal voltage. As the fluid temperature
warms to a normal transmission operating temperature of
100
C (212
F), the sensor resistance becomes less and
the voltage decreases to 1.5 to 2.0 volts.
This DTC detects a high transmission temperature for a
long period of time. This is a type ªDº DTC.
Conditions For Setting The DTC

No TFT DTCs P0712 or P0713.

TFT is greater than 135
C (275
F).

All conditions met for 21 seconds.
Action Taken When The DTC Sets

Hot mode TCC Shift Pattern.

The PCM will not illuminate the CHECK TRANS
Lamp.

ATF Lamp ON. (TFT is greater than 145
C (293
F).)

Disable E±side TCC OFF request.
Conditions For Clearing The DTC

The DTC can be cleared from the PCM history by
using a scan tool.

The DTC will be cleared from history when the vehicle
has achieved 40 warm±up cycles without a failure
reported.

The PCM will cancel the DTC default actions when
the fault no longer exists and the ignition is cycled ªoffº
long enough to power down the PCM.
Diagnostic Aids

Inspect the wiring for poor electrical connections at
the PCM and at the transmission 16±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.

Check harness routing for a potential short to ground
in circuit RED/BLK±GRN/RED.

Scan tool TFT sensor temperature should rise
steadily to about 100
C (212
F), then stabilize.

Check for a ªskewedº (mis±scaled) sensor by
comparing the TFT sensor temperature to the
ambient temperature after a vehicle cold soak. A
ªskewedº sensor can cause delayed garage shifts or
TCC complaints.

Check for a possible torque converter stator problem.

Verify customer driving habits, trailer towing, etc.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart.
3. This test checks for a ªskewedº sensor or shorted
circuit.
4. This test simulates a TFT DTC P0713.