check engine ISUZU AXIOM 2002 Service Repair Manual

7A±15 AUTOMATIC TRANSMISSION (4L30±E)
Chart 4: Poor Shifting In All Gears (All Harsh Or All Soft)
StepActionYe sNo
1Check line pressure. Refer to Line Pressure Test in this section.
Was line pressure normal?Go to Step 2Go to Step 3
21. Check for these conditions which could affect clutch apply
time:
± Defective band apply solenoid (323).
± Defective servo or/and accumulator piston.
± Excessive clutch piston travel.
2. Check of possible causes of internal leaks:
± Cut or damaged sealing ring(s)
± Damaged sealing gasket(s)
± Check ball missing or out of location in 2nd and 3rd clutch
pistons.
3. Check for causes of burned clutch plates or band.
Was the problem found?
Repair or replaceÐ
3Was the line pressure high?
Go to Step 4
Use Chart 15a:
Possible Causes
of Low Line
Pressure in this
section
4Does DTC P0705 set?
Diagnose those
DTC(s) first
Use Chart 15b:
Possible Causes
of High Line
Pressure in this
section
Chart 5a: Delays In Drive And Reverse
NOTE: A short delay (less than 3 seconds) when first
engaging drive or reverse after allowing vehicle to sit
overnight is normal.
Step
ActionYe sNo
1Check line pressure. Refer to Line Pressure Test in this section.
Was line pressure normal?
More than 3
second delay in
drive and reverse
with engine off 1
hour or less.
Teflon seals (508)
on turbine shaft
damaged. Repair
Use Chart 15a:
Possible Causes
of Low Line
Pressure in this
section.
Chart 5b: Delays In Reverse Only
StepActionYe sNo
1Check line pressure. Refer to Line Pressure Test in this section.
Was line pressure normal?
Go to Step 2
Use Chart 15a:
Possible Causes
of Low Line
Pressure in this
section.
2Main case valve body gasket (88) damaged.
± Reverse check ball (85) in valve body (84) missing or out of
location.
± Check for restrictions at valve body transfer plate orifice.
Was the problem found?
RepairÐ

7A±16
AUTOMATIC TRANSMISSION (4L30±E)
Chart 6: Diagnostic Trouble Code (DTC) P0730
StepActionYe sNo
1Check line pressure. Refer to Line Pressure Test in this section.
Was line pressure normal?
Go to Step 2
Use Chart 15b:
Possible Causes
of High Line
Pressure in this
section
21. 1st and 2nd gear missing or 3rd and 4th gear missing.
Check appropriate shift valve. If OK replace solenoid.
2. No engine brake in any range (All ranges in Drive and Reverse
are OK).
Check for suspected conditions modifying delays to clutch
apply:
± Overrun clutch seal damaged.
± Excessive overrun clutch piston travel.
± Defective 3±4 accumulator piston.
± Causes of internal leaks.
± Causes of burned clutch plates.
3. 1st and 4th gear missing or 2nd and 3rd gear missing.
Shift solenoid A stuck. Replace shift solenoid A.
4. DTC P0730 is set in D range 1st gear above 3500 rpm.
Go to
Step 3.
5. DTC P0730 is set in D range 3rd gear between 55-80 mph.
NOTE: Perform this test within safe and legal limits.
Check for suspected conditions modifying delays to clutch
apply:
± 4th clutch seal damaged.
± Excessive 4th clutch piston travel.
± Defective 3±4 accumulator piston.
± Causes of internal leaks.
± Causes of burned clutch plates.
Was the problem found?
Repair or replaceÐ
3Check 3rd gear in ªDº in winter mode.
Does vehicle move?Shift solenoid A
stuck. Replace
shift solenoid A.
Go to Step 4
4Check for suspected conditions modifying delays to clutch apply:
± 2nd clutch seal damaged.
± Excessive 2nd clutch piston travel.
± Defective accumulator piston.
± Causes of internal leaks.
± Check ball missing or out of location in 2nd clutch.
± Seals cut, damaged or missing.
± Gaskets defective.
± Causes of burned clutch plates.
Was the problem found?
Repair or replaceÐ

7A±18
AUTOMATIC TRANSMISSION (4L30±E)
Chart 9c: Coastdown Harsh Shift Or Clunk At 3±2 Downshift
StepActionYe sNo
1Check line pressure. Refer to Line Pressure Test in this section.
Was line pressure normal?
Go to Step 2
Use Chart 15b:
Possible Causes
of High Line
Pressure in this
section
2Does DTC P1850 set?
Diagnose P1850
first
Replace band
apply solenoid
(PWM) (323)
Chart 10: Intermittent 4TH TO 2ND Gear Downshift At Steady Speed
StepActionYe sNo
1Check for consistent speed sensor reading with scan tool.
Was the reading correct?Replace mode
switch for
intermittent
contact.
Go to Step 2
21. Check for wiring harness damage or short to ground. If OK, go
to
(2).
2. Check transmission speed sensor connections. If OK, go to
(3).
3. Replace transmission speed sensor.
Was the replacement complete?
Ð
Replace speed
sensor.
Chart 11: Engine Flare At Shifting During Turning Only (Usually With Warm Engine)
StepActionYe sNo
1Check for oil leaks at transmission.
Was the problem found?Replace
transmission oil
filter and gasket
Ð
Chart 12: Engine Flare During 1±2 Or 2±3 Shift
StepActionYe sNo
1Check line pressure. Refer to Line Pressure Test in this section.
Was line pressure normal?
Go to Step 2
Use Chart 15a:
Possible Causes
of Low Line
Pressure in this
section
21. Check for a stuck 1±2 accumulator valve (320).
2. Check for servo piston (106) leaks.
3. Check for a stuck band apply solenoid (323).
Was line pressure normal?
Repair or replaceÐ

7A±22
AUTOMATIC TRANSMISSION (4L30±E)
Chart 16: Possible Causes Of
Transmission Fluid Leaks
Before attempting to correct an oil leak, the actual source
of the leak must be determined. In many cases, the
source of the leak may be difficult to determine due to
ªwind flowº around the engine and transmission.
The suspected area should be wiped clean before in-
specting for the source of the leak.Oil leaks around the engine and transmission are gener-
ally carried toward the rear of the vehicle by the air
stream. In determining the source of an oil leak, the fol-
lowing two checks should be made:
1. With the engine running, check for external line
pressure leaks.
2. With the engine off, check for oil leaks due to the
raised oil level caused by drainback of converter oil
into the transmission.
Possible Causes Of Fluid Leaks Due To Sealing Malfunction
240RX008
Legend
(1) Electrical Connector (Main Case) Seal
(2) Transmission Vent (Breather)
(3) Speed Sensor O±Ring
(4) Extension (Adapter) Lip Seal
(5) Extension (Adapter) to Main Case Gasket
(6) Overfill and Oil Drain Screws Gasket
(7) Oil Pan Gasket (Main Case)
(8) Selector Shaft Seal(9) Oil Cooler Connectors (2)
(10) Oil Pan Gasket (Adapter Case)
(11) Converter housing attaching bolts not correctly
torqued
(12) Converter Housing Lip Seal
(13) Line Pressure Tap Plug
(14) Electrical Connector (Adapter Case) Seal
(15) Adapter Case Seal Rings (2)

7A±23 AUTOMATIC TRANSMISSION (4L30±E)
Stall Test
The stall test allows you to check the transmission for
internal abrasion and the one way clutch for slippage.
Torque converter performance can also be evaluated.
The stall test results together with the road test results will
identify transmission components requiring servicing or
adjustment.
Stall Test Procedure:
1. Check the level of the engine coolant, the engine oil,
and the automatic transmission fluid. Replenish if
necessary.
2. Block the wheels and set the parking brake.
3. Connect a tachometer to the engine.
4. Start the engine and allow it to idle until the engine
coolant temperature reaches 70 ± 80
C (158 ±
176
F).
5. Hold the brake pedal down as far as it will go.
6. Place the selector in the ªDº range.
7. Gradually push the accelerator pedal to the floor.
The throttle valve will be fully open.
Note the engine speed at which the tachometer
needle stabilizes.
Stall Speed : 2,100 +150 rpm
NOTE: Do not continuously run this test longer than 5
seconds.
8. Release the accelerator pedal.
9. Place the selector in the ªNº range.
10. Run the engine at 1,200 rpm for one minute.
This will cool the transmission fluid.
11. Repeat Steps 7 ± 10 for the ª3º, ª2º, ªLº and ªRº
ranges.
Line Pressure Test
The line pressure test checks oil pump and control valve
pressure regulator valve function. It will also detect oil
leakage.
Line Pressure Test Procedure:
1. Check the level of the engine coolant, the engine oil,
and the automatic transmission fluid.
Replenish if required.
2. Block the wheels and set the parking brake.
3. Remove the pressure detection plug at the left side of
the transmission case.
Set J±29770±A pressure gauge and adapter to the
pressure detection plug hole.
241RS001
4. Start the engine and allow it to idle until the engine
coolant temperature reaches 70 ± 80
C (158 ±
176
F).
5. Hold the brake pedal down as far as it will go.
6. Place the selector in the ªDº range.
7. Note the pressure gauge reading with the engine
idling.
8. Gradually push the accelerator pedal to the floor. The
throttle valve will be fully open.
Note the pressure gauge reading with the accelerator
pedal fully depressed.
NOTE: Do not continuously run this test longer than 5
seconds.
9. Release the accelerator pedal.
10. Place the selector in the ªNº range.
11. Run the engine at 1,200 rpm for one minute.
This will cool the transmission fluid.
12. Repeat Steps 7 ± 11 for the ª3º, ª2º, ªLº, and ªRº
ranges.
13. Install a pressure detection plug to the transmission
case, applying recommended thread locking agent
(LOCTITE 242) or its equivalent to thread of plug.
Make sure that thread is cleaned before applying
locking agents.
14. Tighten the pressure detection plug to the specified
torque.
Torque: 9 ± 14N´m (7 ± 10lb ft)

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).
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 (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 (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.
7. Reset ªOil Life Monitorº data by using Tech 2.
Refer to
Tech 2 OBD II Connection in Transmission
Control System (4L30-E) section.
242R200001
Selector Lever
Inspection
1. Make sure that when the selector 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 selector lever can be shifted as
shown in illustration.
C07RW009
Removal
1. Disconnect battery ground cable.
2. Set ignition Key in ªLOCKº position and selector lever
in ºPº position.
3. Remove knee pads (1), cluster upper cover (2) and
center cluster assembly (3).
740R200021

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±11
Diagnosis
Electronic Diagnosis
How To Diagnose The Problem
1. To avoid incorrect diagnostics, this book needs to be
followed accurately. Unless stated, do not jump
directly to a section that could contain the solution.
Some important information may be missed.
2. The sections in CAPITALS and bold are the main
sections that can be found in the contents.
3. The GO TO ªSECTIONº means to continue to check
going to the ªsectionº.
4. The GO THROUGH ªSECTIONº means to go
through the ªsectionº and then to go back to the place
the GO THROUGH was written.
5. BASIC ELECTRIC CIRCUITS:
You should understand the basic theory of electricity.
This includes the meaning of voltage, amps, ohms,
and what happens in a circuit with an open or shorted
wire. You should also be able to read and understand
wiring diagrams.
Check Trans Indicator
Find CHECK TRANS indicator and verify if it is
A. Flashing: GO TO DIAGNOSTIC CHECK.
B. Staying on: GO THROUGH CHECK TRANS
CHECK.
C. Is never ON when the ignition key is turned on: GO
THROUGH CHECK TRANS CHECK
D. Is ON during 2 seconds at ignition but OFF after:
Normal operation. No DTC or malfunction.
821R200014
Diagnostic Check
This test determines if the transmission or its input or
output connections or sensors are failing.
1. Connect the Tech 2: GO THROUGH Tech 2 OBD II
CONNECTION.2. Turn on the ignition but not the engine.
3. Push ªF0º on Tech 2 to see the Diagnostic Trouble
Code (DTC):
4. Do you have a DTC?
YES: write down all code numbers and do the DTC
CHECK
NO: the DTC can not help you finding the problem.
1. GO THROUGH ªCHECK TRANSº CHECK
2. If it is flashing and the flash is 0.2 seconds ON and
0.2 seconds OFF, this means that you should
have a DTC stored. Please recheck GO TO
DIAGNOSTIC CHECK and if you find the same
problem, replace the Powertrain Control Module
(PCM).
Normal
C07R200005
Abnormal
C07R200006

7A1±12
TRANSMISSION CONTROL SYSTEM (4L30±E)
ªCheck Transº Check
1. Indicator is ON during 2~3 seconds at ignition (or
when the engine is cranked) but it is OFF after the
engine starts. The indicator is working normally GO
TO DIAGNOSTIC CHECK.
821R200014
Normal
C07R200005
2. Indicator is flashing and the flash is 0.2 seconds ON
and 0.2 seconds OFF always when ignition is on
(engine cranked or not). This means that there is a
malfunction. GO TO DIAGNOSTIC CHECK.Abnormal
C07R200006
3. Indicator is staying ON always when Ignition is ON.
1. This means that connection between the lamp
and the indicator control unit is shorted to ground.
2. Verify if instrument panel terminal 27 of connector
I±24 is shorted to ground.
3. Verify if the indicator control unit connector B±16
terminal 20 is shorted to ground.
4. Verify that the instrument panel terminal 14 of
connector I±24 is connected to battery.
5. If problem solved: GO TO CHECK TRANS
INDICATOR.
NO:Replace Powertrain Control Module (PCM).
4. Indicator is staying OFF with the ignition ON (engine
OFF).
1. This means that connection between the lamp
and the indicator control unit is shorted to battery
or opened.
2. Verify if instrument panel terminal 27 of connector
I±24 is shorted to battery or open.
3. Verify if the indicator control unit connector B±16
terminal 20 is shorted to battery or open.
4. Verify that the instrument panel terminal 14 of
connector I±24 is connected to battery. If not,
check the fuses and the connections (terminal 7
of connector H±17) voltage.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±17
Diagnostic Trouble Codes
The purpose of the ªDiagnostic Trouble Codesº mode is to
display stored PCM trouble codes.
When ªDiagnostic Trouble Codesº is selected an
ªApplication Menuº screen appears.
Clear DTC Information
The purpose of the ªClear DTC Informationº mode is to
command the clearing of stored PCM trouble codes.
When ªClear DTC Informationº is selected, a ªClear DTC
Informationº, warning screen appears. This screen
informs you that by cleaning DTC's, ªall stored DTC
information in controller will be erasedº.
Do you want to clear DTC's (Yes/No).
Press either the Yes or No key when answering.
After clearing codes, confirm system operation by test
driving the vehicle.
Allow the vehicle to shift through all four forward gears in a
manner which attempts to repeat the failure condition.
NOTE: When the trouble has not been repaired and the
trouble code cannot be erased, check the vehicle again.
DTC Information
When ªDTC Informationº is selected, an ªApplication
Menuº appears with a list of DTC information function
keys addressing DTC specifics and their origins.
Function key selections may vary for particular vehicle
and/or system.
Data Display
The purpose of the ªData Displayº mode is to
continuously monitor data parameters.
The current actual values of all important sensors and
signals in the system are display through F1 mode.
When ªData Displayº is selected an ªApplication Menuº
appears. Please select either ªEngineº or ªTransmission
Data Displayº.
See ªTransmission Dataº on next page.
Snapshot
When ªSnapshotº is selected an ªApplication Menuº
appears.
When ªTransmission Snapshotº application is selected
from the ªApplication Menuº, a ªSnapshot Menuº
appears, displaying several options. ªSnapshotº options
may vary from one system to another.
ªSnapshotº allows a recording of all vehicle parameters.
There parameters may then be replayed at a future point
in time.
This action allows you to focus on making the condition
occur, rather than trying to view all of the data in
anticipation of the fault. The snapshot will collect
parameter information around a trigger point that you
select.
When a snapshot is taken. It is recorded onto the
PCMCIA memory card. When the Tech 2 is powered
down. Snapshots are not lost.
Actuator Tests
The purpose of ªActuator Testsº mode is to check for
correct operation of electronic system actuators.Lamps
You can operate the lamps by pressing the ON and OFF
buttons.
Preconditions: none
Solenoid
Solenoid 1-2/3-4, Solenoid 2-3, TCC Solenoid
You can operate the solenoids by pressing the ON and
OFF buttons.
Preconditions: P±N position, no vehicle speed, no engine
speed
Band Apply Solenoid
You can operate the solenoid by pressing the ON and
OFF buttons.
Preconditions: P-N position, idle engine speed, no vehicle
speed.
Pressure Control Solenoid (PCS)
You can set desired PCS Current using the ªIncrementº
(+25) and ªDecrementº (±25) button. The PC Solenoid
Data informs about PCS Current, Pressure and Duty
Cycle.
Preconditions: P±N position, no engine speed, no vehicle
speed
Reset Oil Life Monitor
Displays parameter ªOil Life Monitorº and resets to 100%
if Yes-button is pressed on Reset-question. ªNoº leaves
test.
Preconditions: no vehicle speed, no engine speed
NOTE:
Freeze Frame (Powertrain DTC A/B Type)
Freeze Frame is an element of the Diagnostic Manage-
ment System which stores various vehicle information at
the moment an emissions-related fault is stored in
memory and when the MIL is commanded on. These data
can help to identify the cause of a fault. Refer to
Storing
And Erasing Freeze Frame Data
for more detailed in-
formation.
Failure Records (Powertrain DTC C/D Type)
Failure Records data is an enhancement of the OBD II
Freeze Frame feature. Failure Records store the same
vehicle information as does Freeze Frame, but it will store
that information for any fault which is stored in on-board
memory, while Freeze Frame stores information only for
emission-related faults that command the MIL on.

TRANSMISSION CONTROL SYSTEM (4L30±E)7A1±21
810RT022
PIN 1 ± DIAG. SW
PIN 2 ± J1850 Bus + L line on 2±wire systems, or
single wire (Class 2)
PIN 3 ± Active suspension diagnostic enable
PIN 4 ± Chassis ground pin
PIN 5 ± Signal ground pin
PIN 6 ± (Not used)
PIN 7 ± TOD diagnostic enable
PIN 8 ± TOD diagnostic enable
PIN 9 ± Primary UART
PIN 10 ± (Not used)
PIN 11 ± (Not used)
PIN 12 ± ABS diagnostic or CCM diagnostic enable
PIN 13 ± SIR diagnostic enable
PIN 14 ± (Not used)
PIN 15 ± (Not used)
PIN 16 ± Battery power from vehicle unswitched (4
AMP MAX.)
Malfunction Indicator Lamp (MIL)
The Malfunction Indicator Lamp (MIL) looks the same as
the MIL you are already familiar with (ªCHECK ENGINEº
lamp). However, OBD II requires for it illuminate under a
strict set of guidelines. Basically, the MIL is turned on
when the PCM detects a DTC that will impact the vehicle's
emissions.
The MIL is under the control of the Diagnostic Executive.
The MIL will be turned on if a component or system which
has an impact on vehicle emissions indicates a
malfunction or fails to pass an emissions±related
diagnostic test. It will stay on until the system or
component passes the same test, for three consecutive
trips, with no emissions±related faults.
DTC Types
Each DTC is directly related to a diagnostic test. The
Diagnostic Management System sets DTC based on the
failure of the tests during a trip or trips. Certain tests must
fail two (2) consecutive trips before the DTC is set. The
following are the four (4) types of DTCs and the
characteristics of those codes:

Type A

Emissions related

Requests illumination of the MIL of the first trip with a
fail

Stores a History DTC on the first trip with a fail

Stores a Freeze Frame (if empty) (DTC Information
for 6VE1 engine)

Stores a Fail Record

Updates the Fail Record each time the diagnostic
test fails

Type B

Emissions related

ªArmedº after one (1) trip with a fail

ªDisarmedº after one (1) trip with a pass

Requests illumination of the MIL on the
second
consecutive trip
with a fail

Stores a History DTC on the second consecutive trip
with a fail (The DTC will be armed after the first fail)

Stores a Freeze Frame on the second consecutive
trip with a fail (if empty) (DTC Information for 6VE1
engine)

Stores a Fail Record when the first test fails (not
dependent on
consecutive trip fails)

Updates the Fail Record each time the diagnostic
test fails
(Some special conditions apply to misfire and fuel trim
DTCs)

Type C (if the vehicle is so equipped)

Non-Emissions related

Requests illumination of the Service Lamp or the
service message on the Drive Information Center
(DIC) on the
first trip with a fail

Stores a History DTC on the
first trip with a fail


Does not store a Freeze Frame

Stores Fail Record when test fails

Updates the Fail Record each time the diagnostic
test fails

Type D

Non-Emissions related

Not request illumination of any lamp

Stores a History DTC on the
first trip with a fail


Does not store a Freeze Frame

Stores Fail Record when test fails

Updates the Fail Record each time the diagnostic
test fails