light ISUZU AXIOM 2002 Service Repair Manual

6E±574
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
resistance of 100,000 ohms at ±40
C (±40
F). High
temperature causes low resistance of 70 ohms at 130
C
(266
F) . The PCM supplies a 5-volt signal to the sensor
through a resistor in the PCM and monitors the signal
voltage. The voltage will be high when the incoming air is
cold. The voltage will be low when the incoming air is hot.
By measuring the voltage, the PCM calculates the
incoming air temperature. The IAT sensor signal is used
to adjust spark timing according to the incoming air
density.
The Tech 2 displays the temperature of the air entering
the engine. The temperature should read close to the
ambient air temperature when the engine is cold and rise
as underhood temperature increases. If the engine has
not been run for several hours (overnight), the IAT sensor
temperature and engine coolant temperature should read
close to each other. A fault in the IAT sensor circuit will set
DTC P0112 or DTC P0113.
Linear Exhaust Gas Recirculation (EGR)
Control
The PCM monitors the exhaust gas recirculation (EGR)
actual position and adjusts the pintle position accordingly.
The PCM uses information from the following sensors to
control the pintle position:

Engine coolant temperature (ECT) sensor.

Throttle position (TP) sensor.

Mass air flow (MAF) sensor.
Mass Air Flow (MAF) Sensor
The mass air flow (MAF) sensor measures the difference
between the volume and the quantity of air that enters the
engine. ªVolumeº means the size of the space to be filled.
ªQuantityº means the number of air molecules that will fit
into the space. This information is important to the PCM
because heavier, denser air will hold more fuel than
lighter, thinner air. The PCM adjusts the air/fuel ratio as
needed depending on the MAF value. The Tech 2 reads
the MAF value and displays it in terms of grams per
second (gm/s). At idle, the Tech 2 should read between
4-7 gm/s on a fully warmed up engine. Values should
change quickly on acceleration. Values should remain
stable at any given RPM. A failure in the MAF sensor or
circuit will set DTC P0101, DTC P0102, or DTC P0103.
0007
Manifold Absolute Pressure (MAP) Sensor
The manifold absolute pressure (MAP) sensor responds
to changes in intake manifold pressure (vacuum). The
MAP sensor signal voltage to the PCM varies from below
2 volts at idle (high vacuum) to above 4 volts with the
ignition ON, engine not running or at wide-open throttle
(low vacuum).
The MAP sensor is used to determine the following:

Manifold pressure changes while the linear EGR flow
test diagnostic is being run. Refer to
DTC P0401.

Barometric pressure (BARO).
If the PCM 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, respectively. The PCM can
detect a shifted MAP sensor. The PCM compares the
MAP sensor signal to a calculated MAP based on throttle
position and various engine load factors. If the PCM
detects a MAP signal that varies excessively above or
below the calculated value, DTC P0106 will set.
055RW004

6E±575
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Powertrain Control Module (PCM)
The powertrain control module (PCM) is located in the
passenger compartment below the center console. The
PCM controls the following:

Fuel metering system.

Transmission shifting (automatic transmission only).

Ignition timing.

On-board diagnostics for powertrain functions.
The PCM constantly observes the information from
various sensors. The PCM controls the systems that
affect vehicle performance. The PCM performs the
diagnostic function of the system. It can recognize
operational problems, alert the driver through the MIL
(Check Engine lamp), and store diagnostic trouble codes
(DTCs). DTCs identify the problem areas to aid the
technician in making repairs.
PCM Function
The PCM supplies either 5 or 12 volts to power various
sensors or switches. The power is supplied through
resistances in the PCM 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. Tool J 39200 meets this requirement. The PCM
controls output circuits such as the injectors, fan 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)
060RY00068
PCM Components
The PCM is designed to maintain exhaust emission levels
to government mandated standards while providing
excellent driveability and fuel efficiency. The PCM
monitors numerous engine and vehicle functions via
electronic sensors such as the throttle position (TP)sensor, heated oxygen sensor (HO2S), and vehicle
speed sensor (VSS). The PCM also controls certain
engine operations through the following:

Fuel injector control

Ignition control module

ION sensing module

Automatic transmission shift functions

Cruise control

Evaporative emission (EVAP) purge

A/C clutch control
PCM Voltage Description
The PCM supplies a buffered voltage to various switches
and sensors. It can do this because resistance in the
PCM 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 (such as J 39200) to
assure accurate voltage readings.
The input/output devices in the PCM include
analog-to-digital converters, signal buffers, counters,
and special drivers. The PCM 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.
PCM Input/Outputs
Inputs ± Operating Conditions Read

Air Conditioning ªONº or ªOFFº

Engine Coolant Temperature

Crankshaft Position

Exhaust Oxygen Content

Electronic Ignition

Manifold Absolute Pressure

Battery Voltage

Throttle Position

Vehicle Speed

Fuel Pump Voltage

Power Steering Pressure

Intake Air Temperature

Mass Air Flow

Engine Knock

Acceleration Position
Outputs ± Systems Controlled

EVAP Canister Purge

Exhaust Gas Recirculation (EGR)

Ignition Control

Fuel Control

ION Sensing Module

Electric Fuel Pump

Air Conditioning

6E±576
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostics
± Malfunction Indicator Lamp
± Data Link Connector (DLC)
± Data Output

Transmission Control Module
PCM Service Precautions
The PCM 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 PCM's circuits unless
instructed to do so. These circuits should only be tested
using digital voltmeter J 39200. The PCM should remain
connected to the PCM or to a recommended breakout
box.
Reprogramming The PCM
Reprogramming of the PCM is done without removing it
from the vehicle . This provides a flexible and
cost-effective method of making changes in software
calibrations.
Refer to the latest Techline information on
reprogramming or flashing procedures.
Throttle Position (TP) Sensor
The throttle position (TP) sensor is a potentiometer
connected to the throttle shaft on the throttle body. The
PCM monitors the voltage on the signal line and
calculates throttle position. As the throttle valve angle is
changed (accelerator pedal moved), the TP sensor signal
also changes. At a closed throttle position, the output of
the TP1 sensor is low. As the throttle valve opens, the
output increases so that at wide open throttle (WOT), the
output voltage should be above 92% (Tech 2 Display).
The PCM calculates fuel delivery based on throttle valve
angle (driver demand). A broken or loose TP sensor may
cause intermittent bursts of fuel from an injector and
unstable idle because the PCM thinks the throttle is
moving.
060RY00027
Transmission Fluid Temperature (TFT)
Sensor
The transmission fluid temperature sensor is a thermistor
which changes its resistance based on the temperature of
the transmission fluid. For a complete description of the
TFT sensor, refer to
4L30-E Automatic Transmission
Diagnosis
section.
A failure in the TFT sensor or associated wiring will cause
DTC P0712 or DTC P0713 to set. In this case, engine
coolant temperature will be substituted for the TFT
sensor value and the transmission will operate normally.
Transmission Range Switch (Mode 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 PCM which position is selected by the
transmission selector lever. This information is used for
ignition timing, EVAP canister purge, EGR operation.
For more information on the transmission on the
transmission range switch, refer to
4L30-E Automatic
Transmission
section.
Vehicle Speed Sensor (VSS)
The PCM determines the speed of the vehicle by
converting a pulsing voltage signal from the vehicle speed
sensor (VSS) into miles per hour. The PCM uses this
signal to operate the cruise control, speedometer, and the
TCC and shift solenoids in the transmission. For more
information on the TCC and shift solenoids, refer to
4L30-E Automatic Transmission section.
0008
Use of Circuit Testing Tools
Do not use a test light to diagnose the powertrain
electrical systems unless specifically instructed by the
diagnostic procedures. Use Connector Test Adapter Kit J
35616 whenever diagnostic procedures call for probing
connectors.

6E±582
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Crankshaft position (CKP) sensor.
Spark Plug
Although worn or dirty spark plugs may give satisfactory
operation at idling speed, they frequency fail at higher
engine speeds. Faulty spark plugs may cause poor fuel
economy, power loss, loss of speed, hard starting and
generally poor engine performance. Follow the
scheduled maintenance service recommendations to
ensure satisfactory spark plug performance. Refer to
Maintenance and Lubrication section.
Normal spark plug operation will result in brown to
grayish-tan deposits appearing on the insulator portion of
the spark plug. A small amount of red-brown, yellow, and
white powdery material may also be present on the
insulator tip around the center electrode. These deposits
are normal combustion by-products of fuels and
lubricating oils with additives. Some electrode wear will
also occur. Engines which are not running properly are
often referred to as ªmisfiring.º This means the ignition
spark is not igniting the air/fuel mixture at the proper time.
While other ignition and fuel system causes must also be
considered, possible causes include ignition system
conditions which allow the spark voltage to reach ground
in some other manner than by jumping across the air gap
at the tip of the spark plug, leaving the air/fuel mixture
unburned. Refer to
DTC P0300. Misfiring may also occur
when the tip of the spark plug becomes overheated and
ignites the mixture before the spark jumps. This is
referred to as ªpre-ignition.º
Spark plugs may also misfire due to fouling, excessive
gap, or a cracked or broken insulator. If misfiring occurs
before the recommended replacement interval, locate
and correct the cause.
Carbon fouling of the spark plug is indicated by dry, black
carbon (soot) deposits on the portion of the spark plug in
the cylinder. Excessive idling and slow speeds under
light engine loads can keep the spark plug temperatures
so low that these deposits are not burned off. Very rich
fuel mixtures or poor ignition system output may also be
the cause. Refer to DTC P0172.
Oil fouling of the spark plug is indicated by wet oily
deposits on the portion of the spark plug in the cylinder,
usually with little electrode wear. This may be caused by
oil during break-in of new or newly overhauled engines.
Deposit fouling of the spark plug occurs when the normal
red-brown, yellow or white deposits of combustion by
products become sufficient to cause misfiring. In some
cases, these deposits may melt and form a shiny glaze on
the insulator around the center electrode. If the fouling is
found in only one or two cylinders, valve stem clearances
or intake valve seals may be allowing excess lubricating
oil to enter the cylinder, particularly if the deposits are
heavier on the side of the spark plug facing the intake
valve.
TS23995Excessive gap means that the air space between the
center and the side electrodes at the bottom of the spark
plug is too wide for consistent firing. This may be due to
improper gap adjustment or to excessive wear of the
electrode during use. A spark plug gap that is too small
may cause an unstable idle condition. Excessive gap
wear can be an indication of continuous operation at high
speeds or with engine loads, causing the spark to run too
hot. Another possible cause is an excessively lean fuel
mixture.
TS23992Low or high spark plug installation torque or improper
seating can result in the spark plug running too hot and
can cause excessive center electrode wear. The plug
and the cylinder head seats must be in good contact for
proper heat transfer and spark plug cooling. Dirty or
damaged threads in the head or on the spark plug can
keep it from seating even though the proper torque is
applied. Once spark plugs are properly seated, tighten
them to the torque shown in the Specifications Table. Low
torque may result in poor contact of the seats due to a
loose spark plug. Overtightening may cause the spark
plug shell to be stretched and will result in poor contact

6E±591
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Special Tools
ILLUSTRATIONTOOL NO.
TOOL NAME
J 39200
High Impedance
Multimeter (Digital
Voltmeter ± DVM)
(1) PCMCIA Card
(2) RS232 Loop Back
Connector
(3) SAE 16/19 Adapter
(4) DLC Cable
(5) TECH±2
J 34142-B
Unpowered Test Light
Connector Test Adapter
Kit J 35616-A/BT-8637
J 26792/BT-7220-1
Spark Tester
J 34730-E
Port Fuel Injection
Diagnostic Kit
ILLUSTRATIONTOOL NO.
TOOL NAME
J 37027-A
IAC Motor Analyzer
J 23738-A
Vacuum Pump with
Gauge
BT-8515/8515V
Exhaust Back Pressure
Tester
J 39194-B
Heated Oxygen Sensor
Wrench
J 35689-A
Terminal Remover
J 28742-A
Weather Pack II
Terminal Remover

6E±592
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
ILLUSTRATIONTOOL NO.
TOOL NAME
J 39021-90
Injector Switch Box
J 39021-65
Injector Test Light
J 41413

EVAP Pressure/Purge
Diagnostic Station
J 41416
Ultrasonic Leak Detector
1. J 41413 EVAP Pressure/Purge Diagnostic Station is
a multipurpose tool which is used to perform several
diagnostic procedures for enhanced emission
testing. The station will accommodate a nitrogen gas
filled cylinder which is used to pressurize the vehicle
EVAP system for a leakdown test and leak location
test when a vehicle is repaired for leakage in the
enhanced evaporative emission control system. It
also has two additional gauges (inches of mercury
and inches of water) which are used to measure both
source vacuum and EVAP canister purge vacuum to
verify correct operation and vapor flow within the
canister purge circuit.
2. J 41416 Ultrasonic Leak Detector is a
microprocessor-based device used to detect leaks in
the enhanced evaporative emission control system.
The evaporative system is pressurized to 30 inches of
water using the J 41413 EVAP Pressure/Purge
Diagnostic System. Small leaks in the EVAP system
will emit sound at a high frequency undetectable by a
human ear but detectable with the J 41416. The
technician traces along the evaporative system and
can pinpoint leaks due to corroded lines, cracked
hoses, or a damaged EVAP component. The
detector includes a high quality set of headphones to
block out surrounding shop noise and the LED
sensitivity meter allows a visual reference for locating
leaks in conjunction with the audio output heard
through the headphones. Powered by (1) nine volt
battery.

6G±12
ENGINE LUBRICATION (6VE1 3.5L)
Oil Filter
Removal
1. Disconnect battery ground cable.
2. Drain engine oil.
3. Remove oil filter using J-36390 filter wrench.
Installation
1. Apply a light coat of engine oil to the oil filter gasket.
2. Hand tighten the filter until the gasket contacts the
sealing face.
3. Using J±36390 filter wrench, tighten the filter an
additional 7/8 turn or by torque 22 N´m (16 lb ft).
050RW001
Legend
(1) Oil Pump
(2) Oil Filter
(3) Oil Gallery
(4) From Filter
(5) To Filter
4. Fill the oil to the proper lever by following the oil level
check procedures.
5. Reconnect battery ground cable.
6. Run the engine and inspect for leaks.

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 (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)
242R200001
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±TRANSPARENT
/ PINKBROWN
DRAIN
REQUIRED?NOYESYESYES
CONTAMINA±
TIONNONEVery small amount of
foreign material in
bottom of panContamination by cool-
ant or other sourceLarge pieces of metal
or other foreign
material 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 complaints 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 seconds and then goes out and
remains out.

If the lamp is flashing, GO TO Check Trans
Indicator in Transmission Control System
(4L30±E) section.
If no serial data is present, GO TO OBD System
Check. Refer to
Driveability and Emissions in
Engine section.

If the lamp stays ON or stays OFF, GO TO 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.

7A±35 AUTOMATIC TRANSMISSION (4L30±E)
5. Check that cable moves smoothly, lightly pulling outer
cable rearward.
6. Connect lock adjust, aligning ªTº mark in the ªUpº
position.
256R200003
7. About following installation steps, refer to Selector
Lever in this section.
8. Check the shift lock operation:
a. Selector lever should not be moved out of ªPº
position with ignition key in ªLockº position.
b. Selector lever can be moved out of ªPº position with
ignition key in ªONºposition only when brake pedal
is depressed.
c. ignition key can be turned to ªLOCKº position only
when selector lever is in ªPº position (key can be
pulled out).
9. If a. and c. fail, readjust cable. If b. fails, readjust
connector wiring and brake pedal switch.
Mode Switch
Removal
1. Place selector lever in neutral.
2. Disconnect battery ground cable.
3. Remove mode switch cover (1) (V6).
4. Disconnect selector lever (2) from the mode switch.
5. Remove bracket with cable (3).
6. Disconnect transmission harness from the mode
switch connector (4).
7. Remove bracket with mode switch connector from
the transmission case.
8. Remove mode switch connector (4) from the bracket
(5).
9. Remove two mode switch bolts and nut then remove
mode switch (6).
210RW014