2002 ISUZU AXIOM instrument panel

5A±10BRAKE CONTROL SYSTEM
System Components
Electronic Hydraulic Control Unit (EHCU), three Wheel
Speed Sensors, Warning Light, and G-sensor.
Electronic Hydraulic Control Unit (EHCU)
The EHCU consists of ABS control circuits, fault detector,
and a fail-safe. The signal received from each sensor
activates the hydraulic unit accordingly and cancels the
ABS to return to normal braking if a malfunction occurs in
the ABS system.
The EHCU has a self-diagnosing function which can
indicate faulty circuits during diagnosis.
The EHCU is mounted on the engine compartment rear
right side. It consists of a Motor, Plunger Pump, Solenoid
Valves.
Solenoid Valves: Reduces or holds the caliper fluid
pressure for each front disc brake or both rear disc brakes
according to the signal sent from the EHCU.
Reservoir: Temporarily holds the brake fluid that returns
from the front and rear disc brake caliper so that pressure
of front disc brake caliper can be reduced smoothly.
Plunger Pump: Feeds the brake fluid held in the reservoir
to the master cylinder.
Motor: Drives the pump according to the signal from
EHCU.
Check Valve: Controls the brake fluid flow.
ABS Warning Light
821R200015Vehicles equipped with the Anti-lock Brake System have
an amber ªABSº warning light in the instrument panel.
The ªABSº warning light will illuminate if a malfunction in
the Anti-lock Brake System is detected by the Electronic
Hydraulic Control Unit (EHCU).In case of an electronic
malfunction, the EHCU will turn ªONº the ªABSº warning
light and disable the Anti-lock braking function.
The ªABSº light will turn ªONº for approximately three
seconds after the ignition switch is turned to the ªONº
position.If the ªABSº light stays ªONº after the ignition switch is
turned to the ªONº position, or comes ªONº and stays
ªONº while driving, the Anti-lock Brake System should be
inspected for a malfunction according to the diagnosis
procedure.
Wheel Speed Sensor
It consists of a sensor and a rotor. The sensor is attached
to the knuckle on the front wheels and to the rear axle
case on the rear differential.
The front sensor rotor is attached to the each brake rotor
by bolts.
The rear rotor is press-fit in the differential case.
The magnetic flux generated from electrodes magnetized
by a magnet in the sensor varies due to rotation of the
rotor, and the electromagnetic induction generates
alternating voltage in the coil. This voltage draws a ªsine
curveº with the frequency proportional to rotor speed and
it allows detection of wheel speed.
G-Sensor
The G-sensor installed inside the EHCU detects the
vehicle deceleration speed and sends a signal to the
EHCU. In 4WD operation, all four wheels may be
decelerated in almost the same phase, since all wheels
are connected mechanically.
This tendency is noticeable particularly on roads with low
friction coefficient, and the ABS control is adversely
affected.
The G-sensor judges whether the friction coefficient of
road surface is low or high, and changes the EHCU's
operating system to ensure ABS control.
Normal and Anti-lock Braking
Under normal driving conditions, the Anti-lock Brake
System functions the same as a standard power assisted
brake system. However, with the detection of wheel
lock-up, a slight bump or kick-back will be felt in the brake
pedal. This pedal ªbumpº will be followed by a series of
short pedal pulsations which occurs in rapid succession.
The brake pedal pulsation will continue until there is no
longer a need for the anti-lock function or until the vehicle
is stopped. A slight ticking or popping noise may be heard
during brake applications when the Anti-lock features is
being used.
When the Anti-lock feature is being used, the brake pedal
may rise even as the brakes are being applied. This is
also normal. Maintaining a constant force on the pedal
will provide the shortest stopping distance.
Brake Pedal Travel
Vehicles equipped with the Anti-lock Brake System may
be stopped by applying normal force to the brake pedal.
Although there is no need to push the pedal beyond the
point where it stops or holds the vehicle, by applying more
force the pedal will continue to travel toward the floor.
This extra brake pedal travel is normal.

6A±18
ENGINE MECHANICAL (6VE1 3.5L)
Malfunction Indicator Lamp
The instrument panel ªCHECK ENGINEº Malfunction In-
dicator Lamp (MIL) illuminates by self diagnostic system
when the system checks the starting of engine, or senses
malfunctions.
Condition
Possible causeCorrection
ªCHECK ENGINEº MIL does not
illuminate at the starting of engine
Bulb defectiveReplace
illuminate at the starting of engineMIL circuit openCorrect or replace
Command signal circuit to operate
self diagnostic system shortedCorrect or replace
Powertrain Control Module (PCM)
cable loosely connected,
disconnected or defectiveCorrect or replace
PCM defectiveReplace
ªCHECK ENGINEº MIL illuminates,
and stays onDeterioration of heated oxygen
sensor internal elementReplace
Heated oxygen sensor connector
terminal improper contactReconnect properly
Heated oxygen sensor lead wire
shortedCorrect
Heated oxygen sensor circuit openCorrect or replace
Deterioration of engine coolant
temperature sensor internal elementReplace
Engine coolant temperature sensor
connector terminal improper contactReconnect properly
Engine coolant temperature sensor
lead wire shortedCorrect
Engine coolant temperature sensor
circuit openCorrect or replace
Throttle position sensor open or
shorted circuitsCorrect or replace
Deterioration of crankshaft position
sensorReplace
Crankshaft position sensor circuit
open or shortedCorrect or replace
Vehicle speed sensor circuit openCorrect or replace
Manifold absolute pressure sensor
circuit open or shortedCorrect or replace
Intake air temperature sensor circuit
open or shortedCorrect or replace
Fuel injector circuit open or shortedCorrect or replace
PCM driver transistor defectiveReplace PCM
Malfunctioning of PCM RAM
(Random Access Memory) or ROM
(Read Only Memory)Replace PCM

6E±1
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
AXIOM
ENGINE
6VE1 3.5L ENGINE
DRIVEABILITY AND EMISSIONS
CONTENTS
Specifications 6E±6. . . . . . . . . . . . . . . . . . . . . . . . . . .
Tightening Specifications 6E±6. . . . . . . . . . . . . . .
Diagrams and Schematics 6E±7. . . . . . . . . . . . . . . .
PCM Wiring Diagram (1 of 7) 6E±7. . . . . . . . . . . .
PCM Wiring Diagram (2 of 7) 6E±8. . . . . . . . . . . .
PCM Wiring Diagram (3 of 7) 6E±9. . . . . . . . . . . .
PCM Wiring Diagram (4 of 7) 6E±10. . . . . . . . . . . .
PCM Wiring Diagram (5 of 7) 6E±11. . . . . . . . . . . .
PCM Wiring Diagram (6 of 7) 6E±12. . . . . . . . . . . .
PCM Wiring Diagram (7 of 7) 6E±13. . . . . . . . . . . .
PCM Pinouts 6E±14. . . . . . . . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Blue Connector
± Row ªF1 ~ 20º 6E±14. . . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Blue Connector
± Row ªF20 ~ 40º 6E±15. . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Blue Connector
± Row ªF41 ~ 60º 6E±16. . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Blue Connector
± Row ªF61 ~ 80º 6E±17. . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Red Connector
± Row ªS1 ~ 20º 6E±19. . . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Red Connector
± Row ªS21 ~ 40º 6E±21. . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Red Connector
± Row ªS41 ~ 60º 6E±23. . . . . . . . . . . . . . . . . . . . .
PCM Pinout Table, 80-Way Red Connector
± Row ªS61 ~ 80º 6E±25. . . . . . . . . . . . . . . . . . . . .
Component Locators 6E±27. . . . . . . . . . . . . . . . . . .
Undercarriage Component Locator 6E±29. . . . . .
Fuse and Relay Panel (Underhood
Electrical Center) 6E±30. . . . . . . . . . . . . . . . . . . . .
Sensors and Miscellaneous Component
Locators 6E±31. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnosis 6E±33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Strategy-Based Diagnostics 6E±33. . . . . . . . . . . . .
DTC Stored 6E±33. . . . . . . . . . . . . . . . . . . . . . . . . . .
No DTC 6E±33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
No Matching Symptom 6E±33. . . . . . . . . . . . . . . . .
Intermittents 6E±33. . . . . . . . . . . . . . . . . . . . . . . . . .
No Trouble Found 6E±33. . . . . . . . . . . . . . . . . . . . .
Verifying Vehicle Repair 6E±33. . . . . . . . . . . . . . . .
General Service Information 6E±33. . . . . . . . . . . . . .
OBD II Serviceablity Issues 6E±33. . . . . . . . . . . . .
Emissions Control Information Label 6E±34. . . . .
Visual / Physical Engine Compartment
Inspection 6E±34. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic Knowledge of Tools Required 6E±35. . . . . .
Serial Data Communications 6E±35. . . . . . . . . . . . . . Class 2 Serial Data Communications 6E±35. . . . .
On-Board Diagnostic (OBD II) 6E±35. . . . . . . . . . . . .
On-Board Diagnostic Tests 6E±35. . . . . . . . . . . . .
Comprehensive Component Monitor
Diagnostic Operation 6E±35. . . . . . . . . . . . . . . . . .
System Status and Drive Cycle for
Satisfying Federal Inspection/Maintenance
(I/M 240) Regulations 6E±36. . . . . . . . . . . . . . . . . .
Common OBD II Terms 6E±36. . . . . . . . . . . . . . . . .
The Diagnostic Executive 6E±36. . . . . . . . . . . . . . .
DTC Types 6E±37. . . . . . . . . . . . . . . . . . . . . . . . . . .
Decimal/Binary/Hexadecimal Conversions 6E±39
Verifying Vehicle Repair 6E±39. . . . . . . . . . . . . . . .
Reading Diagnostic Trouble Codes Using
The Tech 2 Scan Tool 6E±39. . . . . . . . . . . . . . . . .
Tech 2 6E±40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tech 2 Features 6E±41. . . . . . . . . . . . . . . . . . . . . . .
Getting Started 6E±41. . . . . . . . . . . . . . . . . . . . . . . .
Operating Procedure (For Example) 6E±42. . . . .
DTC Modes 6E±43. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC Information Mode 6E±43. . . . . . . . . . . . . . . . .
Miscellaneous Test 6E±44. . . . . . . . . . . . . . . . . . . .
Lamps Test 6E±44. . . . . . . . . . . . . . . . . . . . . . . . . . .
Relays Test 6E±46. . . . . . . . . . . . . . . . . . . . . . . . . . .
EVAP Test 6E±47. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel System Test 6E±48. . . . . . . . . . . . . . . . . . . . . .
Instruments Test 6E±50. . . . . . . . . . . . . . . . . . . . . . .
EGR Control Test 6E±52. . . . . . . . . . . . . . . . . . . . . .
Variable Intake Manifold Solenoid Test 6E±52. . .
Injector Balance Test 6E±54. . . . . . . . . . . . . . . . . . .
Plotting Snapshot Graph 6E±54. . . . . . . . . . . . . . . . .
Plotting Graph Flow Chart (Plotting graph
after obtaining vehicle information) 6E±55. . . . . .
Flow Chart for Snapshot Replay (Plotting
Graph) 6E±56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Primary System-Based Diagnostic 6E±57. . . . . . . . .
Primary System-Based Diagnostic 6E±57. . . . . . .
Fuel Control Heated Oxygen Sensor 6E±57. . . . .
HO2S Heater 6E±57. . . . . . . . . . . . . . . . . . . . . . . . .
Catalyst Monitor Heated Oxygen Sensors
and Diagnostic Operation 6E±57. . . . . . . . . . . . . .
Misfire Monitor Diagnostic Operation 6E±58. . . . . . .
Misfire Monitor Diagnostic Operation 6E±58. . . . .
Misfire Counters 6E±58. . . . . . . . . . . . . . . . . . . . . . .

6E±28
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Engine Component Locator Table
Number
NameLocation
1Linear Exhaust Gas Recirculation (EGR) ValveRear right side of the engine
2Throttle Position (TP) SensorOn the throttle body
3Intake Air Temperature (IAT) SensorOn the intake air duct near the throttle body
4Check Engine (MIL) LightOn the instrument panel beneath the
tachometer
5Positive Crankcase Ventilation (PCV) ValveOn the left of the cylinder head cover
6Air CleanerLeft front of the engine bay
7Mass Air Flow (MAF) SensorAttached to the air filter box
8Fuel RailOn the Common Chamber
9Fuel Pressure RegulatorRear side of the engine
10ION Sensing moduleBolted to the top of the Common Chamber
11Common ChamberTop of the engine
12EVAP Duty Solenoid ValveBolted to the front of the coolant pipe
13Fuse/Relay BoxAlong the inside of the right fender
14Manifold Absolute Pressure (MAP) SensorBolted to the top of the Common Chamber
15Throttle BodyBetween the intake air duct and the Common
Chamber
16Engine Coolant Temperature SensorOn the coolant crossover pipe at the front of
the engine, near the throttle body
17Power Train Control Module (PCM)Along the inside of the left fender

6E±37
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
The Diagnostic Executive records DTCs and turns on the
MIL when emission-related faults occur. It can also turn
off the MIL if the conditions cease which caused the DTC
to set.
Diagnostic Information
The diagnostic charts and functional checks are designed
to locate a faulty circuit or component through a process
of logical decisions. The charts are prepared with the
requirement that the vehicle functioned correctly at the
time of assembly and that there are no multiple faults
present.
There is a continuous self-diagnosis on certain control
functions. This diagnostic capability is complemented by
the diagnostic procedures contained in this manual. The
language of communicating the source of the malfunction
is a system of diagnostic trouble codes. When a
malfunction is detected by the control module, a
diagnostic trouble code is set and the Malfunction
Indicator Lamp (MIL) (ªCheck Engineº lamp) is
illuminated.
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 that it illuminate under a
strict set of guide lines.
Basically, the MIL is turned on when the PCM detects a
DTC that will impact vehicle emissions.
The MIL is under the control of the Diagnostic Executive.
The MIL will be turned on if an emissions-related
diagnostic test indicates a malfunction has occurred. It
will stay on until the system or component passes the
same test, for three consecutive trips, with no emissions
related faults.
If the vehicle is experiencing a misfire malfunction which
may cause damage to the Three-Way Catalytic
Converter (TWC), the MIL will flash once per second.
This will continue until the vehicle is outside of speed and
load conditions which could cause possible catalyst
damage, and the MIL will stop flashing and remain on
steady.
Extinguishing the MIL
When the MIL is on, the Diagnostic Executive will turn off
the MIL after
three(3) consecutive trips that a ªtest
passedº has been reported for the diagnostic test that
originally caused the MIL to illuminate.
Although the MIL has been turned off, the DTC will remain
in the PCM memory (both Freeze Frame and Failure
Records) until
forty(40) warm-up cycles after no faults
have been completed.
If the MIL was set by either a fuel trim or misfire-related
DTC, additional requirements must be met. In addition to
the requirements stated in the previous paragraph, these
requirements are as follows:

The diagnostic tests that are passed must occur
within 375 RPM of the RPM data stored at the time the
last test failed.

Plus or minus ten (10) percent of the engine load that
was stored at the time the last failed.
Similar engine temperature conditions (warmed up or
warming up ) as those stored at the time the last test
failed.
Meeting these requirements ensures that the fault which
turned on the MIL has been corrected.
The MIL (ªCheck Engineº lamp) is on the instrument
panel and has the following function:

It informs the driver that a fault affects vehicle
emission levels has occurred and that the vehicle
should be taken for service as soon as possible.

As a bulb and system check, the MIL will come ªONº
with the key ªONº and the engine not running. When
the engine is started, the MIL will turn ªOFF.º

When the MIL remains ªONº while the engine is
running, or when a malfunction is suspected due to a
driveability or emissions problem, a Powertrain
On-Board Diagnostic (OBD ll) System Check must be
performed. The procedures for these checks are
given in On-Board Diagnostic (OBD) System Check.
These checks will expose faults which may not be
detected if other diagnostics are performed first.
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)

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)

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

Stores a History DTC on the
first trip with a fail

6E±38
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

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
IMPORTANT:Only four Fail Records can be stored.
Each Fail Record is for a different DTC. It is possible that
there will not be Fail Records for every DTC if multiple
DTCs are set.
Special Cases of Type B Diagnostic Tests
Unique to the misfire diagnostic, the Diagnostic Executive
has the capability of alerting the vehicle operator to
potentially damaging levels of misfire. If a misfire
condition exists that could potentially damage the
catalytic converter as a result of high misfire levels, the
Diagnostic Executive will command the MIL to ªflashº at a
rate of once per second during those the time that the
catalyst damaging misfire condition is present.
Fuel trim and misfire are special cases of
Type B
diagnostics. Each time a fuel trim or misfire malfunction is
detected, engine load, engine speed, and engine coolant
temperature are recorded.
When the ignition is turned off, the last reported set of
conditions remain stored. During subsequent ignition
cycles, the stored conditions are used as reference for
similar conditions. If a malfunction occurs during two
consecutive trips, the Diagnostic Executive treats the
failure as a normal
Type B diagnostic, and does not use
the stored conditions. However, if a malfunction occurs
on two non-consecutive trips, the stored conditions are
compared with the current conditions. The MIL will then
illuminate under the following conditions:

When the engine load conditions are within 10% of
the previous test that failed.

Engine speed is within 375 rpm, of the previous test
that failed.

Engine coolant temperature is in the same range as
the previous test that failed.Storing and Erasing Freeze Frame Data and Failure
Records
Government regulations require that engine operating
conditions be captured whenever the MIL is illuminated.
The data captured is called Freeze Frame data. The
Freeze Frame data is very similar to a single record of
operating conditions. Whenever the MIL is illuminated,
the corresponding record of operating conditions is
recorded to the Freeze Frame buffer.
Freeze Frame data can only be overwritten with data
associated with a misfire or fuel trim malfunction. Data
from these faults take precedence over data associated
with any other fault. The Freeze Frame data will not be
erased unless the associated history DTC is cleared.
Each time a diagnostic test reports a failure, the current
engine operating conditions are recorded in the
Failure
Records
buffer. A subsequent failure will update the
recorded operating conditions. The following operating
conditions for the diagnostic test which failed
typically
include the following parameters:

Air Fuel Ratio

Air Flow Rate

Fuel Trim

Engine Speed

Engine Load

Engine Coolant Temperature

Vehicle Speed

TP Angle

AP Angle

MAP/BARO

Injector Base Pulse Width

Loop Status
Intermittent Malfunction Indicator Lamp
In the case of an ªintermittentº fault, the MIL (ªCheck
Engineº lamp) may illuminate and then (after three trips)
go ªOFFº. However, the corresponding diagnostic trouble
code will be stored in memory. When unexpected
diagnostic trouble codes appear, check for an intermittent
malfunction.
A diagnostic trouble code may reset. Consult the
ªDiagnostic Aidsº associated with the diagnostic trouble
code. A physical inspection of the applicable sub-system
most often will resolve the problem.
Data Link Connector (DLC)
The provision for communication with the control module
is the Data Link Connector (DLC). It is located at the
lower left of the instrument panel behind a small square
cover. The DLC is used to connect to the Tech 2 Scan
Tool. Some common uses of the Tech 2 are listed below:

6E±86
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Malfunction Indicator Lamp (MIL)

 
StepNo Ye s Value(s) Action
15Locate and repair the short to ground in the PCM
ignition feed circuit or PCM battery feed circuit.
Is the action complete?
ÐVerify repairÐ
16Locate and repair the short to ground in the ignition
feed circuit to the instrument cluster, and replace the
fuse.
Is the action complete?
ÐVerify repairÐ
17Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
PCM in ON-Vehicle Service for
procedures.
And also refer to latest Service Bulletin.
Check to see if the Latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.
Is the action complete?
ÐVerify repairÐ
18Check the MIL driver circuit for a poor connection at the
instrument panel connector.
Was a problem found?
ÐVerify repair
Go to
Instrument
Panel
in
Electrical
Diagnosis

6E±87
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Malfunction Indicator Lamp (MIL) ªONº Steady
060R200049
Circuit description
The malfunction indicator lamp (MIL) should always be
illuminated and steady with ignition ªONº and the engine
stopped. Ignition feed voltage is supplied directly to the
MIL indicator. The powertrain control module (PCM)
turns the MIL ªONº by grounding the MIL driver circuit.
The MIL should not remain ªONº with the engine running
and no DTC(s) set. A steady MIL with the engine running
and no DTC(s) suggests a short to ground in the MIL
driver circuit.
Diagnostic Aids
An intermittent 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 MIL does not remain ªONº when the PCM is
disconnected, the MIL driver wiring is not faulty.
3. If the MIL driver circuit is OK, the instrument panel
cluster is faulty.
6. 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.