1998 ISUZU TROOPER check engine light

6E±153 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
10. To avoid backprobing the VSS and possibly
damaging a seal or terminal, the VSS output can be
tested at the point where the transmission harness
connected to the engine harness. The green 16-way
connector is adjacent to a blue 16-way connector,
and it can be easily accessed by removing the air
cleaner assembly. The green 16-way connector is
separated, and battery voltage is applied to the VSS
through the yellow wire at one corner of the
connector. The VSS output can be monitored with a
DVM connected to the blue wire with a black tracer.
The two wires are next to each other in the 16-way
connector . The test connections are made on the
transmission side of the connector, the side that is
not clipped to the body sheetmetal.11. The speedometer-to-ECM VSS signal wire is
spliced to a wire leading to the cruise control
module. If a short to ground or voltage is found
between the ECM and speedometer, it could be
located between the splice and the cruise control
module.
DTC P0502 ±VSS No Signal

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Does the speedometer work?ÐGo to Step 10Go to Step 3
31. Disconnect the VSS connector.
2. Ignition ªON.º
3. Using a test light to battery +, probe the connector
ground wire.
Did the light illuminate?
ÐGo to Step 5Go to Step 4
4Repair the sensor ground.
Is the action complete?
ÐVerify repairÐ
51. Ignition ªON,º sensor disconnected.
2. Using a DVM, measure at the VSS connector
between ground and voltage supply.
Was the measurement near the specified value?
Battery
voltage
Go to Step 7Go to Step 6
6Repair the open or short to ground which may have
blown the meter fuse.
Is the action complete?
ÐVerify repairÐ
71. Ignition ªON,º VSS disconnected.
2. Using a DVM, measure at the VSS connector
between ground and the blue/black wire from the
speedometer.
Was the measurement near the specified value?
7.5-8 VGo to Step 9Go to Step 8
8Check for an open or short circuit between the
speedometer and the VSS.
Was an open or short circuit located?
ÐVerify repairGo to Step 9
9Replace the VSS.
Is the action complete?
ÐVerify repairGo to Step 10
10Replace the speedometer.
Is the action complete?
ÐVerify repairGo to Step 11

6E±159 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0562 (Flash DTC 35)
System Voltage Too Low
Circuit Description
The engine control module (ECM) monitors the system
voltage on the ignition feed terminals to the ECM. A
system voltage DTC will set whenever the voltage is
above a calibrated value.
Action Taken When the DTC Sets

The ECM will not illuminate the malfunction indicator
lamp (MIL).

The ECM will store as Failure Records only conditions
which were present when the DTC was set. This
information will not be stored as Freeze Frame data.
Conditions for Clearing the MIL/DTC

DTC P0563 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the ECM battery
feed.
Diagnostic Aids
If the DTC sets when an accessory is operated, check for
a poor connection or defective accessory.
DTC P0562 ± System Voltage Too Low

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Using a DVM, measure the battery voltage at the
battery.
Is the battery voltage greater than the specified value?
11.5 VGo to Step 3
Charge
battery, then
go to
Step 3
31. Install a Tech 2.
2. Select ªIgnition Voltsº on the Tech 2.
3. Start the engine and raise the engine speed to the
specified value.
4. Load the electrical system by turning on the
headlights, high blower, etc.
Is the ignition voltage approximately equal to the
specified value?
2000 RPM
12.8-14.1 V
Go to Step 4
Go to
Starting/
Charging
41. Ignition ªOFF.º
2. Disconnect the ECM connector at the ECM.
3. Using a DVM, measure the battery voltage at the
ECM connector.
Is it approximately equal to battery voltage?
Ð
Check for
excessive
current draw
with ignition
ªOFF,º engine
ªOFF.º
Go to Step 5
51. Check for faulty connections at the ECM harness
terminals.
2. Repair as necessary.
Was a repair necessary?
ÐVerify repairGo to Step 6
6Check for an open battery feed circuit to the ECM.
Is the action complete?
ÐVerify repairGo to Step 7
7Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairÐ

6E±176
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Symptom Diagnosis
Preliminary Checks
Before using this section, perform the ªOn±Board
Diagnostic (OBD) System Checkº and verify all of the
following items:

The powertrain control module (ECM) and
malfunction indicator lamp (MIL) (CHECK ENGINE
lamp) are operating correctly.

There are no DTC(s) stored.

Tech±2 data is within normal operating range. Refer
to
Typical Scan Data Values.

Verify the customer complaint and locate the correct
symptom in the table of contents. Perform the
procedure included in the symptom chart.
Visual/Physical Check
Several of the symptom procedures call for a careful
visual/physical check. This can lead to correcting a
problem without further checks and can save valuable
time.
This check should include the following items:

ECM grounds for cleanliness, tightness and proper
location.

Vacuum hoses for splits, kinks, and proper
connections, as shown on the ªVehicle Emission
Control Informationº label. Check thoroughly for any
type of leak or restriction.

Air intake ducts for collapsed or damaged areas.

Injector wires for cracking, hardness, and carbon
tracking.

Wiring for proper connections, pinches and cuts.
Intermittents
IMPORTANT:An intermittent problem may or may not
turn on the malfunction indicator lamp (MIL) or store a
DTC. DO NOT use the Diagnostic Trouble Code (DTC)
charts for intermittent problems. The fault must be
present to locate the problem.
Most intermittent problems are caused by faulty electrical
connections or wiring. Perform a careful visual/physical
check for the following conditions:

Poor mating of the connector halves or a terminal not
fully seated in the connector (backed out).

Improperly formed or damaged terminal.

All connector terminals in the problem circuit should
be carefully checked for proper contact tension.

Poor terminal±to±wire connection. This requires
removing the terminal from the connector body to
check.
Road test the vehicle with a Digital Multimeter
(5-8840-0285-0) connected to a suspected circuit. An
abnormal voltage when the malfunction occurs is a good
indication that there is a fault in the circuit being
monitored.
Use a scan tool to help detect intermittent conditions. The
scan tools have several features that can be used to
locate an intermittent condition. Use the following feature
to find intermittent faults:
Using a Tech±2 ªFreeze Frameº buffer or ªFailure
Recordsº buffer can aid in locating an intermittent
condition. Review and record the information in the
freeze frame or failure record associated with the
intermittent DTC being diagnosed. The vehicle can
be driven within the conditions that were present
when the DTC originally set.
To check for loss of diagnostic code memory, disconnect
the MAP sensor and idle the engine until the MIL (CHECK
ENGINE lamp) comes on. DTC P0107 should be stored
and kept in memory when the ignition is turned ªOFF.º If
not, the ECM is faulty. When this test is completed, make
sure that you clear the DTC P0107 from memory.
An intermittent MIL (CHECK ENGINE lamp) with no
stored DTC may be caused by the following:

MIL (CHECK ENGINE lamp) wire to ECM shorted to
ground.

Poor ECM grounds. Refer to the ECM wiring
diagrams.
Check for improper installation of electrical options such
as lights, cellular phones, etc.
Check for an open diode across the A/C compressor
clutch and check for other open diodes (refer to wiring
diagrams in
Electrical Diagnosis).
If problem has not been found, refer to
ECM Connector
Symptom
tables.

6E±196
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
QOS System Doesn't Work

StepActionValue(s)Ye sNo
1Was OBD System check performed?
ÐGo to Step 2
Go to OBD
System
Check
2Check glawplug indicator light. If bulb is broken,
replace.
Was a problem found?
ÐVerify repairGo to Step 3
31. Connect a circuit tester between glawplug & engine
ground.
2. With ignition on and engine off, check if the glaw
indicator and circuit tester indicate power voltage
for 9 to 13 sec. If not indicated, repair terminal & wire
harness.
Was repair needed?
ÐVerify repairGo to Step 4
41. Connect a circuit tester between glawplug and
engine ground.
2. With engine on, check if voltage continues for 180
sec. If not, inspect and repair glaw relay.
Was repair needed?
ÐVerify repairGo to Step 5
51. Remove the glawplug, and if damaged, replace.
2. Check glawplug resistance.
Was resistance as specified?
0.8 ± 1
Go to Step 7Go to Step 6
6Replace glawplug.
Was measure completed?
ÐVerify repairGo to Step 7
71. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:

Visual/physical inspection

Tech 2 data

Freeze Frame data/Failure Records butter

All electrical connections within a suspected
circuit and/or system
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repair
Contact
Technical
Assistance

6E±210
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Vehicle Speed Sensor (VSS)
Removal Procedure
CAUTION: The VSS is located on the right side of
the transfer case just ahead of the rear propeller
shaft and very close to the exhaust pipes. Be sure
that the exhaust pipes are cool enough to touch
before trying to remove the VSS. If the pipes are hot,
you could be burned.
1. Disconnect the negative battery cable.
2. Disconnect the VSS electrical connector.
TS23748
3. Remove the bolt and the clamp securing the VSS in
place.
IMPORTANT:Have a container ready to catch any fluid
that leaks out when the VSS is removed from the transfer
case.
TS23780
4. Remove the VSS from the transfer case by wiggling it
slightly and pulling it straight out.
Inspection Procedure
1. Inspect the electrical connector for signs of corrosion
or warping. Replace the VSS if the electrical
connector is corroded or warped.
2. Inspect the VSS driven gear for chips, breaks, or worn
condition. Replace the VSS if the driven gear is
chipped, broken or worn.
3. Inspect the O-ring for wear, nicks, tears, or
looseness. Replace the O-ring if necessary.
Installation Procedure
1. Install the VSS in the transfer case with the notch for
the connector facing the rear.
2. Secure the VSS in place with the clamp and the bolt.
Tighten

Tighten the bolt to 16 N´m (12 lb ft.).
TS23780
3. Connect the VSS electrical connector.
TS23748
4. Check the transfer case oil level. Add fluid if
necessary.

7A±10
AUTOMATIC TRANSMISSION (4L30±E)
Checking Transmission Fluid Level
and Condition
Checking fluid level and condition (color and odor) at
regular intervals will provide early diagnosis information
about the transmission. This information may be used to
correct a condition that, if not detected early, could result
in major transmission repairs.
IMPORTANT:When new, automatic transmission fluid
is red in color. As the vehicle is driven, the transmission
fluid will begin to look darker in color. The color may
eventually appear light brown.
A dark brown color with burnt odor may indicate
excessive fluid deterioration and signal a need for fluid
change.
Fluid Level
When adding or changing fluid, use only DEXRON )±III.
Refer to Maintenance and Lubrication in General
Information section for maintenance information and
servicing interval.
CAUTION: DO NOT OVERFILL.
Overfilling will cause foaming, loss of fluid, abnor-
mal shifting and possible damage to the transmis-
sion.
1. Park the vehicle on level ground and apply the parking
brake firmly.
2. Check fluid level with engine running at idle.
NOTE: Be sure that transmission fluid temperature is
below 30
C (86
F).
3. Move the selector lever through all gear ranges.
4. Move the selector lever to ªParkº.
5. Let engine idle for 3 minutes and open the overfill
screw (1).
6. Add released transmission fluid until it flows out over
the overfill screw opening.
7. Let engine idle until a fluid temperature between 32
C
(90
F) and 57
C (135
F) is reached, 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: Check transmission fluid temperature with scan
tool.
Minimum fluid level " 57
C (135
F)
Maximum fluid level " 32
C (90
F)
242RW003
CAUTION: Do not open overfill screw with engine
stopped.
CAUTION: DO NOT CHECK FLUID LEVEL UNDER
THESE CONDITIONS:

Immediately after driving at sustained highway
speeds.

In heavy city traffic during hot weather.

If vehicle is towing a trailer.
If the vehicle has been operated under these conditions,
shut the engine off and allow the vehicle to ªcoolº for thirty
(30) minutes. After the cool down period, restart the
vehicle and continue from step 2 above.

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.

7A1±10
TRANSMISSION CONTROL SYSTEM (4L30±E)
Functions of Input / Output Components
ComponentsFunction
Speed sensor
(fixed to transmission
(T/M))Senses rotation of output shaft and feeds the data to Powertrain Control Module
(PCM).
Throttle position sensor
(TPS)
(fixed to engine)Senses the extent of throttle valve opening and the speed of the throttle valve
lever motion to open the valve. Feeds the data to PCM.
I
N
Brake Switch (SW)
(fixed to brake pedal)Senses whether the driver has pressed the brake pedal or not and feeds the
information to PCM.
N-
P
U
Kickdown SW
(fixed to accelerator pedal)Senses whether the driver has pushed the accelerator pedal fully or not, and
feeds the information to PCM.
U
TMode SW (fixed to T/M)Senses the select lever position, and feeds the information to PCM.

S
I
Power drive SW
(fixed to front console)Senses whether the driver has selected the power mode, and feeds the informa-
tion to PCM.
I
G-T/M oil temp. sensorSenses the T/M oil temperature and feeds the data to PCM
N
A
L
Engine coolant tempera-
ture sensorSenses the engine coolant temperature, and feeds the data to PCM.
LEngine speed signalFeeds the signals monitoring engine speed to PCM from crank angle sensor.
Air conditioning informationSenses whether the air conditioner has been switched on or not, and feeds the
information to PCM.
Winter switch (fixed to front
console)Senses whether the driver has selected the winter mode, and feeds the informa-
tion to PCM.
Cruise controller * (Over-
drive OFF signal)Downshift takes place when Overdrive OFF signal is received from auto cruise
control unit.
S
Shift solenoid A, BSelects shift point and gear position suited to the vehicle running condition on
the basis of PCM output.
O
S
O-
L
Band apply solenoidControls oil flow suited to the vehicle running condition on the basis of PCM out-
put.
O
U
T-
P
E-
N
O
Torque Converter
Clutch solenoidControls clutch engagement/disengagement suited to the vehicle running condi-
tion on the basis of PCM output.
P
U
T

O
I
DForce motor
(Pressure regulator
valve)Adjusts the oil pump delivery pressure to line pressure suited to the vehicle run-
ning condition on the basis of PCM output.

S
I
Power drive mode lampInforms the driver whether the vehicle is in power mode or not.
I
G-Winter drive mode lampInforms the driver whether the vehicle is in winter mode or not.G
N
A
L
T/M monitor lamp
(ªCHECK TRANSº)Informs the driver of failure in the system.
LATF warning lampLights when ATF oil temperature rises.
ABS signal *When the select lever is at ªReverseº or ªLº range, sends a signal to the ABS
controller as one of the ABS control conditions.
* If equipped