2002 ISUZU AXIOM turn signal

5A±52BRAKE CONTROL SYSTEM
Chart B-24 Wheel Speed Input Abnormality (DTC 65 (Flash out) / C0238 (Serial
communications))
StepActionYe sNo
1Using TECH 2?Go to Step 2Go to Step 3
21. Connect TECH 2.
2. Select Snap shot manual trigger.
3. With wheel speed data displayed, run the vehicle when speed
has arrived at 30 km/h (18 mph).
4. Check speed data on each wheel (refer to the criterion given
below). * 1
Is the abnormal sensor condition found?
Replace.
Go to
Step 8
Go to Step 3
All the sensors
should follow the
following
flowchart (without
using TECH 2).
3Is there play in sensor/sensor ring?Repair.
Go to
Step 8Go to Step 4
4Is there powdered iron sticking to sensor/sensor ring?Repair.
Go to
Step 8Go to Step 5
5Is there a broken tooth or indentation in sensor ring?Replace sensor
ring.
Go to
Step 8Go to Step 6
6Is there play in wheel bearing?Adjust or repair.
Go to
Step 8Go to Step 7
7Is the check wiring between sensor and coil integrated module
normal?
Replace EHCU.
Go to
Step 8
Repair, and
perform system
self-check.
Go to
Step 8
81. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat `Basic
diagnostic flow
chartº
Go to Step 8
Sensor Signal Abnormality Criteria using TECH 2
1. While driving, the speed of one or two wheels is 25%
or more higher or lower than that of the other wheels.
2. The speed of one or two wheels is 10 km/h (6 mph) or
more higher or lower than that of the other wheels.
3. During steady driving, wheel speed changes abruptly.
*1 The vehicle must run on a level paved road.
NOTE: Even after repairing the faulty part the warning
light (W/L) does not go out if the vehicle is at a stop.
Turn the ignition switch to the ON position and drive the
vehicle at 12 km/h (8 mph) or higher to make sure that the
warning light goes out.
It is important to verify that the correct tires are installed
on vehicle.

6C±3 ENGINE FUEL (6VE1 3.5L)
When working on the fuel system, there are several
things to keep in mind:

Any time the fuel system is being worked on,
disconnect the battery ground cable except for those
tests where battery voltage is required.

Always keep a dry chemical (Class B) fire
extinguisher near the work area.

Replace all pipes with the same pipe and fittings that
were removed.

Clean and inspect ªOº rings. Replace if required.

Always relieve the line pressure before servicing any
fuel system components.

Do not attempt repairs on the fuel system until you
have read the instructions and checked the pictures
relating to that repair.

Adhere to all Notices and Cautions.
All gasoline engines are designed to use only unleaded
gasoline. Unleaded gasoline must be used for proper
emission control system operation.
Its use will also minimize spark plug fouling and extend
engine oil life. Using leaded gasoline can damage the
emission control system and could result in loss of
emission warranty coverage.
The vapor pressure sensor and vent solenoid valve for
vapor pressure sensor are used to detect abnormalities in
the evaporative emission control system.
The PCM decides whether there is an abnormality in the
evaporative emission control system based on vapor
pressure sensor signal.Fuel Metering
The Powertrain Control Module (PCM) is in complete
control of this fuel delivery system during normal driving
conditions.
The intake manifold function, like that of a diesel, is used
only to let air into the engine. The fuel is injected by
separate injectors that are mounted over the intake
manifold.
The Manifold Absolute Pressure (MAP) sensor measures
the changes in the intake manifold pressure which result
from engine load and speed changes, which the MAP
sensor converts to a voltage output.
This sensor generates the voltage to change
corresponding to the flow of the air drawn into the engine.
The changing voltage is transformed into an electric
signal and provided to the PCM.
With receipt of the signals sent from the MAP sensor,
Intake Air Temperature sensor and others, the PCM
determines an appropriate fuel injection pulse width
feeding such information to the fuel injector valves to
affect an appropriate air/fuel ratio.
The Multiport Fuel Injection system utilizes an injection
system where the injectors turn on at every crankshaft
revolution. The PCM controls the injector on time so that
the correct amount of fuel is metered depending on
driving conditions.
Two interchangeable ªOº rings are used on the injector
that must be replaced when the injectors are removed.
The fuel rail is attached to the top of the intake manifold
and supplies fuel to all the injectors.
Fuel is recirculated through the rail continually while the
engine is running. This removes air and vapors from the
fuel as well as keeping the fuel cool during hot weather
operation.
The fuel pressure control valve that is mounted on the fuel
rail maintains a pressure differential across the injectors
under all operating conditions. It is accomplished by
controlling the amount of fuel that is recirculated back to
the fuel tank based on engine demand.
See Section ªDriveability and Emissionº for more
information and diagnosis.

6D2±2
IGNITION SYSTEM (6VE1 3.5L)
General Description
Ignition is done by the electronic ignition (El) that directly
fires the spark plugs from ignition coils through spark plug
wires without using a distributor. The firing orders are
selected No.1, No.2, No.3, No.4, No.5, and No6.
Since the cylinder on exhaust stroke requires less energy
to fire its ignition plug, energy from the ignition coils can be
utilized to fire the mating cylinder on compression stroke.
After additional 360
rotation, respective cylinder strokes
are reversed.
The EI consists of six ignition coils,ignition control
module, crank position sensor, powertrain control module
(PCM) and other components.
The ignition coils are connected with the PCM by means
of a 80 pin connector.The ignition control module turns on/off the primary circuit
of ignition coils, and also it controls the ignition timing at
the engine speed below 538 rpm.
A notch in the timing disc on the crankshaft activates the
crank position sensor which then sends information such
as firing order and starting timing of each ignition coil to
the PCM.
Further, the El employs ignition control (IC) to control
similar to a distributor system.
By receiving signals such as crank position,engine
speed, water temperature and Manifold Absolute
Pressure (MAP), the PCM controls the ignition timing.
D06RY00037
Diagnosis
Refer to Section Drivability and Emissions for the
diagnosis to electronic ignition system (El system).

6E±57
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Primary System-Based Diagnostic
Primary System-Based Diagnostic
There are primary system-based diagnostics which
evaluate system operation and its effect on vehicle
emissions. The primary system-based diagnostics are
listed below with a brief description of the diagnostic
function:
Oxygen Sensor Diagnosis
The fuel control heated oxygen sensors (Bank 1 HO2S 1
and Bank 2 HO2S 1) are diagnosed for the following
conditions:

Heater performance (time to activity on cold start)

Slow response

Response time (time to switch R/L or L/R)

Inactive signal (output steady at bias voltage ±
approx. 450 mV)

Signal fixed high

Signal fixed low
The catalyst monitor heated oxygen sensors (Bank 1
HO2S 2 and Bank 2 HO2S 2) are diagnosed for the
following conditions:

Heater performance (time to activity on cold start).

Signal fixed low during steady state conditions or
power enrichment (hard acceleration when a rich
mixture should be indicated).

Signal fixed high during steady state conditions or
deceleration mode (deceleration when a lean mixture
should be indicated).

Inactive sensor (output steady at approx. 438 mV).
If the oxygen sensor pigtail wiring, connector or terminal
are damaged, the entire oxygen sensor assembly must
be replaced. DO NOT attempt to repair the wiring,
connector or terminals. In order for the sensor to function
properly, it must have clean reference air provided to it.
This clean air reference is obtained by way of the oxygen
sensor wire(s). Any attempt to repair the wires, connector
or terminals could result in the obstruction of the
reference air and degrade oxygen sensor performance.
Refer to
On-Vehicle Service, Heated Oxygen Sensors in
this section.
Fuel Control Heated Oxygen Sensor
The main function of the fuel control heated oxygen
sensors is to provide the control module with exhaust
stream oxygen content information to allow proper fueling
and maintain emissions within mandated levels. After it
reaches operating temperature, the sensor will generate
a voltage, inversely proportional to the amount of oxygen
present in the exhaust gases. The control module uses
the signal voltage from the fuel control heated oxygen
sensors while in closed loop to adjust fuel injector pulse
width. While in closed loop, the PCM can adjust fuel
delivery to maintain an air/fuel ratio which allows the best
combination of emission control and driveability. The fuel
control heated oxygen sensors are also used to
determine catalyst efficiency.
HO2S Heater
Heated oxygen sensors are used to minimize the amount
of time required for closed loop fuel control to begin
operation and to allow accurate catalyst monitoring. The
oxygen sensor heater greatly decreases the amount of
time required for fuel control sensors (Bank 1 HO2S 1 and
Bank2 HO2S 1) to become active. Oxygen sensor
heaters are required by catalyst monitor and sensor
(Bank 1 HO2S 2 and Bank 2 HO2S 2) to maintain a
sufficiently high temperature which allows accurate
exhaust oxygen content readings further away from the
engine.
Catalyst Monitor Heated Oxygen Sensors
and Diagnostic Operation
TS24067
To control emissions of hydrocarbons (HC), carbon
monoxide (CO), and oxides of nitrogen (NOx), a
three-way catalytic converter is used. The catalyst within
the converter promotes a chemical reaction which
oxidizes the HC and CO present in the exhaust gas,
converting them into harmless water vapor and carbon
dioxide. The catalyst also reduces NOx, converting it to
nitrogen. The PCM has the ability to monitor this process
using the pre-catalyst and post-catalyst heated oxygen
sensors. The pre-catalyst sensor produces an output
signal which indicates the amount of oxygen present in
the exhaust gas entering the three-way catalytic
converter. The post-catalyst sensor produces an output
signal which indicates the oxygen storage capacity of the
catalyst; this in turn indicates the catalyst's ability to
convert exhaust gases efficiently. If the catalyst is
operating efficiently, the pre-catalyst signal will be far
more active than that produced by the post-catalyst
sensor.
In addition to catalyst monitoring, the heated oxygen
sensors have a limited role in controlling fuel delivery. If
the sensor signal indicates a high or low oxygen content
for an extended period of time while in closed loop, the
PCM will adjust the fuel delivery slightly to compensate.

6E±73
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Powertrain Control Module (PCM)
Diagnosis
To read and clear diagnostic trouble codes, use a Tech 2.
IMPORTANT:Use of a Tech 2 is recommended to clear
diagnostic trouble codes from the PCM memory.
Diagnostic trouble codes can also be cleared by turning
the ignition ªOFFº and disconnecting the battery power
from the PCM for 30 seconds. Turning off the ignition and
disconnecting the battery power from the PCM will cause
all diagnostic information in the PCM memory to be
cleared. Therefore, all the diagnostic tests will have to be
re-run.
Since the PCM can have a failure which may affect only
one circuit, following the diagnostic procedures in this
section will determine which circuit has a problem and
where it is.
If a diagnostic chart indicates that the PCM connections
or the PCM is the cause of a problem, and the PCM is
replaced, but this does not correct the problem, one of the
following may be the reason:

There is a problem with the PCM terminal
connections. The terminals may have to be removed
from the connector in order to check them properly.

EEPROM program is not correct for the application.
Incorrect components or reprogramming the PCM
with the wrong EEPROM program may cause a
malfunction and may or may not set a DTC.

The problem is intermittent. This means that the
problem is not present at the time the system is being
checked. In this case, refer to the
Symptoms portion
of the manual and make a careful physical inspection
of all component and wiring associated with the
affected system.

There is a shorted solenoid, relay coil, or harness.
Solenoids and relays are turned ªONº and ªOFFº by
the PCM using internal electronic switches called
drivers. A shorted solenoid, relay coil, or harness will
not damage the PCM but will cause the solenoid or
relay to be inoperative.
Multiple PCM Information Sensor
DTCs Set
Circuit Description
The powertrain control module (PCM) monitors various
sensors to determine the engine operating conditions.
The PCM controls fuel delivery, spark advance,
transmission operation, and emission control device
operation based on the sensor inputs.
The PCM provides a sensor ground to all of the sensors.
The PCM applies 5 volts through a pull±up resistor, and
determines the status of the following sensors by
monitoring the voltage present between the 5±volt supply
and the resistor:

The engine coolant temperature (ECT) sensor

The intake air temperature (IAT) sensor

The transmission fluid temperature (TFT) sensorThe PCM provides the following sensors with a 5±volt
reference and a sensor ground signal:
1

The exhaust gas recirculating (EGR) pintle position
sensor

The manifold absolute pressure (MAP) sensor

The throttle position (TP) sensor 1

The acceleration position (AP) sensor 1

The acceleration position (AP) sensor 3

The Vapor Pressure Sensor
2

The Crank position (CKP) sensor

The throttle position (TP) sensor 2

The acceleration position (AP) sensor 2
The PCM monitors the separate feedback signals from
these sensors in order to determine their operating
status.
Diagnostic Aids
IMPORTANT:Be sure to inspect PCM and engine
grounds for being secure and clean.
A short to voltage in one of the sensor input circuits may
cause one or more of the following DTCs to be set:

P0425

P0108, P1106

P0406

P1120, P1515, P1221, P1516, P1635

P1275, P1639, P1271, P1273

P1285, P1272, P1273

P0336, P0337

P1220, P1515, P1221, P1515, P1516

P1280, P1271, P1272
IMPORTANT:If a sensor input circuit has been shorted
to voltage, ensure that the sensor is not damaged. A
damaged sensor will continue to indicate a high or low
voltage after the affected circuit has been repaired. If the
sensor has been damaged, replace it.
An open in the sensor ground circuit between the PCM
and the splice will cause one or more of the following
DTCs to be set:

P0425

P0108, P1106

P0406

P1120, P1515, P1221, P1516, P1635

P1275, P1639, P1271, P1273

P1285, P1272, P1273

P0336, P0337

P1220, P1515, P1221, P1515, P1516

P1280, P1271, P1272
A short to ground in the 5±volt reference A or B circuit will
cause one or more of the following DTCs to be set:

P0453

P0106, P0107, P1107

P0401, P1404, P0405

P1120, P1515, P1221, P1516, P1635

6E±89
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Reduced Power Lamp (RPL)
060R200073
Circuit Description
The Reduced Power lamp (RPL) should always be
illuminated and steady with the ignition ªONº and the
engine stopped. Ignition feed voltage is supplied to the
RPL bulb through the meter fuse. The powertrain control
module (PCM) orders the RPL ªONº signal for Multiplex
Control Unit. When Multiplex Control Unit is received RPL
ªONº signal that turn RPL ªONº by grounding the RPL
driver circuit.
Diagnostic Aids
An intermittent RPL may be caused by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation. Check for the following items:

Inspect the PCM and Multiplex Control Unit harness
and connections for improper mating, broken locks,
improperly formed or damaged terminals, poor
terminal to wire connection, and damaged harness.

If the engine runs OK, check for a faulty light bulb, an
open in the MIL driver circuit, or an open in the
instrument cluster ignition feed.

If the engine cranks but will not run, check for an open
PCM ignition or battery feed, or a poor PCM to engine
ground.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.2. A ªNo RPLº condition accompanied by a no±start
condition suggests a faulty PCM ignition feed or
battery feed circuit.
9. Using a test light connected to B+, probe each of the
Multiplex Control Unit ground terminals to ensure
that a good ground is present. Refer to Multiplex
Control Unit Terminal End View for terminal
locations of the Unit Terminal End View for terminal
locations of the Multiplex Control Unit ground
circuits.
12.Using a test light connected to B+, probe each of
the PCM ground terminals to ensure that a good
ground is present. Refer to PCM Terminal End View
for terminal locations of the PCM ground circuits.
21.In this step, temporarily substitute a known good
relay for the PCM relay. The horn relay is nearby,
and it can be verified as ªgoodº simply by honking
the horn. Replace the horn relay after completing
this step.
24.This vehicle is equipped with a PCM which utilizes
an electrically erasable programmable read only
memory (EEPROM). When the PCM is replaced,
the new PCM must be programmed. Refer to PCM
Replacement and Programming Procedures in
Powertrain Control Module (PCM) and Sensors.

6E±93
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Reduced Power Lamp (RPL) ªONº Steady
060R200073
Circuit Description
The Reduced Power lamp (RPL) should always be
illuminated and steady with the ignition ªONº and the
engine stopped. Ignition feed voltage is supplied to the
RPL bulb through the meter fuse. The powertrain control
module (PCM) orders the RPL ªONº signal for Multiplex
Control Unit. When Multiplex Control Unit is received RPL
ªONº signal that turn RPL ªONº by grounding the RPL
driver circuit.
The RPL should not remain ªONº with the engine running
and no DTC(s) set. A steady RPL with the engine running
and no DTC(s) suggests a short to ground in the RPL
driver circuit.
Diagnostic Aids
An intermittent RPL may be caused by a poor connection,
rubbed through wire insulation, or a wire broken inside the
insulation. Check for the following items:
Poor connection or damaged harness ± Inspect the
PCM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal to wire connection, and
damaged harness.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. If the RPL does not remain ªONº when the Multiplex
Control Unit is disconnected, the RPL driver wiring
is not faulty.
3. If the RPL driver circuit is OK, the instrument panel
cluster is faulty.
10. This vehicle is equipped with a PCM which utilizes
an electrically erasable programmable read only
memory (EEPROM). When the PCM is replaced,
the new PCM must be programmed. Refer to PCM
Replacement and Programming Procedures in
Powertrain Control Module (PCM) and Sensors.

6E±96
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Starter Control System Check
060R200062
Circuit Description
Starter control system is controlled by the Power Train
Control Module (PCM). The PCM monitors starter switch
signal (ªSTARTºposition ) and MODE switch (park or
neutral) signal. PCM is operated by the ignition switch.
Ignition feed voltage is supplied to the MODE switch and
starter relay through the engine fuse. PCM turns the
starter relay ªONº by grounding the starter relay driver
circuit.
The starter motor is operated until 30 seconds based on
starter relay signal.
Diagnostic Aids
An intermittent may be caused by the following:

Poor connections.

Mis routed harness.
Rubbed through wire insulation.

Broken wire inside the insulation.
Test Description
2.If Anti-theft system is ªONº, PCM does not operate
starter control system.
19.Refer to
6D section.
21.Refer to 6D section.
24.This vehicle is equipped with a PCM which utilizes
an electrically erasable programmable read only
memory (EEPROM). When the PCM is replaced,the
new PCM must be programmed.
Refer to
PCM Replacement and Programming
Procedures in Powertrain Control Module (PCM) and
Sensors.
Starter Control System Check

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Was the ªAnti-theft Systemº normally? Refer to
Owner's Manual.ÐGo to Step 3Go to Step 7