6E–176
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Symptom Diagnosis
Preliminary Checks
Before using this section, perform the “On–Board
Diagnostic (OBD) System Check” 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 “Vehicle Emission
Control Information” 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 “Freeze Frame” buffer or “Failure
Records” 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 “OFF.” 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
StepActionVa l u e ( s )Ye sNo
1Was OBD System check performed?
—Go to Step 2
Go to OBD
System
Check
2Check glawplug indicator light. If bulb is broken,
replace.
Was a problem found?
—Verify 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?
—Verify 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?
—Verify repairGo to Step 5
51. Remove the glawplug, and if damaged, replace.
2. Check glawplug resistance.
Was resistance as specified?
0.8 – 1Go to Step 7Go to Step 6
6Replace glawplug.
Was measure completed?
—Verify 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
Te c h 2 d a t a
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?
—Verify repair
Contact
Te c h n i c a l
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:H a v e a c o n t a i n e r r e a d y t o c a t c h a n y f l u i d
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 Nꞏm (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 (86F).
3. Move the selector lever through all gear ranges.
4. Move the selector lever to “Park”.
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 57C (135F) is reached, then close the
overfill screw (1).
Torque: 38 N
m (3.9 kgꞏm/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
57C (135F)
Maximum fluid level
32C (90F)
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 “cool” 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.
Te s t D r i v i n g
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 “CHECK TRANS” 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 “Check
Trans” 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 “CHECK TRANS” lamp
comes on, use the scan tool to check for trouble
codes.
4. If, during the test drive, a problem is felt, but the
“CHECK TRANS” 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 “D”, 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
(“CHECK TRANS”)Informs the driver of failure in the system.
LATF warning lampLights when ATF oil temperature rises.
ABS signal *When the select lever is at “Reverse” or “L” range, sends a signal to the ABS
controller as one of the ABS control conditions.
* If equipped
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 “trigger” 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
Ty p eEngine
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)
7A1–28
TRANSMISSION CONTROL SYSTEM (4L30–E)
DTC P0560 System Voltage Malfunction
StepActionYe sNo
11. Install the scan tool.
2. With the engine “off”, turn the ignition switch “on”.
NOTE: Before clearing DTC(s), use the scan tool to record “Failure
Records” for reference, as data will be lost when the “Clear Info”
function is used.
3. Record the DTC “Failure Records”. Note: If any other DTCs
are present, refer to their applicable diagnostic charts before
continuing.
4. Using the J–39200 DVOM, measure the battery voltage
across the battery terminals. Record the measurement for
future reference.
Is the voltage higher than 10.5 volts?
Go to Step 2
Go to Engine
Electrical in
Engine section
2Start the engine and warm to normal operating temperature.
Is the generator/check engine light “on”?Go to Starting
and Charging
System in Engine
section
Go to Step 3
31. Increase the engine speed to 1,000–1,500 rpm.
2. Observe scan tool system voltage.
Is the system voltage within 13–15 volts.
Go to Step 4
Go to Starting
and Charging
System in Engine
section
41. Turn the ignition switch “off”.
2. Disconnect the J1(RED) and J3 (BLUE) PCM connector
(additional DTCs will set).
3. With the engine “off”, turn the ignition switch “on”.
4. Using the J39200 DVOM, measure the battery voltage input at
PCM connector terminals J1–A4 and J3–E16.
Is there a voltage variance between the voltage measured at the
battery (taken in Step 1) and at terminals J1–A4 and J3–E16 that
is greater than 0.5 volts?
Go to Step 5Go to Step 6
5Repair the high resistance condition in circuit WHT.
Was the circuit repaired?
Go to Step 10—
61. Disconnect the J3 (BLUE) PCM connector.
2. Measure the ignition voltage input at PCM connector terminals
J3–E16 and J3–F16.
Is there a voltage variance between the voltage measured at the
battery (taken in Step 1) and at terminals J3–E16 and J3–F16 that
is greater than 0.5 volts?
Go to Step 7Go to Step 8
7Repair the high resistance condition is circuit RED/BLU.
Was the circuit repaired?
Go to Step 10—
8Check PCM connector terminals J1–A4, J3–E16 and J3–F16 for
bent, damaged, or backed out connector pins. Also check for
weak terminal tension.
Was a problem found?
Go to Step 10Go to Step 9