check engine light ISUZU AXIOM 2002 Service Owner's Manual

6D1±2
ENGINE ELECTRICAL (6VE1 3.5L)
Battery
General Description
The battery is completely sealed except for the two small
vent holes (2) on the side. These vent holes (2) permit the
escape of small amounts of gas generated by the battery.
This type of battery has the following advantages over
conventional batteries:
1. There is no need to add water during the entire
service life of the battery.
2. The battery is much less vulnerable to self discharge
than a conventional type battery.
Diagnosis
1. Visual Inspection
Inspect the battery for obvious physical damage, such as
a cracked or broken case, which would permit electrolyte
loss.
Replace the battery if obvious physical damage is
discovered during inspection.
Check for any other physical damage and correct it as
necessary.
2. Hydrometer Check
There is a built±in hydrometer (Charge test indicator(1))
at the top of the battery. It is designed to be used during
diagnostic procedures.
Before trying to read the hydrometer, carefully clean the
upper battery surface.
If your work area is poorly lit, additional light may be
necessary to read the hydrometer.
a. BLUE RING OR DOT VISIBLE(4) ± Go to Step 3.
b. BLUE RING OR DOT NOT VISIBLE(3) ± Replace
the battery.
061R200001
3. Voltage Check
1. Put voltmeter test leads to battery terminals.
a. VOLTAGE IS 12.4V OR ABOVE ± Go to Step 4
Load Test.
b. VOLTAGE IS UNDER 12.4V ± Go to procedure (2)
below.
2. Determine fast charge amperage from specification.
(See Main Data and Specifications in this section).
Fast charge battery for 30 minutes at amperage rate
no higher than specified value.
Take voltage and amperage readings after charge.
a. VOLTAGE IS ABOVE 16V AT BELOW 1/3 OF
AMPERAGE RATE ± Replace battery.
b. VOLTAGE IS ABOVE 16V AT ABOVE 1/3 OF
AMPERAGE RATE ± Drop charging voltage to 15V
and charge for 10 ± 15 hours. Then go to Step 4
Load Test.
c. VOLTAGE IS BETWEEN 12V AND 16V ±
Continue charging at the same rate for an
additional 3±1/2 hours. Then go to Step 4 Load
Test.
d. VOLTAGE BELOW 12V ± Replace the Battery.
4. Load Test
1. Connect a voltmeter and a battery load tester across
the battery terminals.
2. Apply 300 ampere load for 15 seconds to remove
surface charge from the battery. Remove load.
3. Wait 15 seconds to let battery recover. Then apply
specified load from specifications (See Main Data
and Specifications in this section).
Read voltage after 15 seconds, then remove load.
a. VOLTAGE DOES NOT DROP BELOW THE
MINIMUM LISTED IN THE TABLE ± The battery is
good and should be returned to service.
b. VOLTAGE IS LESS THAN MINIMUM LISTED ±
Replace the battery.
ESTIMATED TEMPERATURE
MINIMUM
VOLTAGE

F
CV
70219.6
60169.5
50109.4
4049.3
30±19.1
20±78.9
10±128.7
0±188.5
The battery temperature must be estimated by feel
and by the temperature the battery has been
exposed to for the preceding few hours.

6D3±17
STARTING AND CHARGING SYSTEM (6VE1 3.5L)
Charging System
General Description
The IC integral regulator charging system and its main
components are connected as shown in illustration.
The regulator is a solid state type and it is mounted along
with the brush holder assembly inside the generator
installed on the rear end cover.
The generator does not require particular maintenance
such as voltage adjustment.The rectifier connected to the stator coil has diodes to
transform AC voltage into DC voltage.
This DC voltage is connected to the output terminal of
generator.
F06RX002
General On±Vehicle Inspection
A basic wiring diagram is shown in the illustration. When
operating normally, the indicator bulb will come on when
the switch is turned on, and will then go out when the
engine starts. If the indicator operates abnormally, or if an
undercharged or overcharged battery condition occurs,
the following procedure may be used to diagnose the
charging system. Remember that an undercharged
battery is often caused by accessories being left on
overnight, or by a defective switch which allows a bulb,
such as a trunk or glove box light, to stay on.
Observe the following procedure:
1. Visually check belt and wiring.
2. Go to step 5. for vehicles without charge indicator
light.
3. Switch on, engine stopped, light should be on. If not,
detach harness at generator, ground ªLº terminal
lead.a. Lamp lights, replace or repair generator.
b. Lamp dose not light, locate open circuit between
grounding lead and ignition switch. Bulb may be
open.
4. Switch on, engine running at moderate speed. Light
should be off. If not, detach wiring harness at
generator.
a. If light goes off, replace or repair generator.
b. If light stays on, check for grounded ªLº terminal
wire in harness.
5. Battery undercharged or overcharged.
a. Detach wiring harness connector from generator.
b. With switch on, engine not running connect
voltmeter from ground to ªLº terminal in wiring
harness, and to ªIGº terminal. If used. Wiring
harness may connect to either ªLº or ªIGº or both.
c. Zero reading indicates open circuit between
terminal and battery. Connect as required.

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±33
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnosis
Strategy-Based Diagnostics
Strategy-Based Diagnostics
The strategy-based diagnostic is a uniform approach to
repair all Electrical/Electronic (E/E) systems. The
diagnostic flow can always be used to resolve an E/E
system problem and is a starting point when repairs are
necessary. The following steps will instruct the technician
how to proceed with a diagnosis:
1. Verify the customer complaint.

To verify the customer complaint, the technician
should know the normal operation of the system.
2. Perform preliminary checks.

Conduct a thorough visual inspection.

Review the service history.

Detect unusual sounds or odors.

Gather diagnostic trouble code information to
achieve an effective repair.
3. Check bulletins and other service information.

This includes videos, newsletters, etc.
4. Refer to service information (manual) system
check(s).

ªSystem checksº contain information on a system
that may not be supported by one or more DTCs.
System checks verify proper operation of the
system. This will lead the technician in an
organized approach to diagnostics.
5. Refer to service diagnostics.
DTC Stored
Follow the designated DTC chart exactly to make an
effective repair.
No DTC
Select the symptom from the symptom tables. Follow the
diagnostic paths or suggestions to complete the repair.
You may refer to the applicable component/system check
in the system checks.
No Matching Symptom
1. Analyze the complaint.
2. Develop a plan for diagnostics.
3. Utilize the wiring diagrams and the theory of
operation.
Combine technician knowledge with efficient use of the
available service information.
Intermittents
Conditions that are not always present are called
intermittents. To resolve intermittents, perform the
following steps:
1. Observe history DTCs, DTC modes, and freeze
frame data.
2. Evaluate the symptoms and the conditions described
by the customer.3. Use a check sheet or other method to identify the
circuit or electrical system component.
4. Follow the suggestions for intermittent diagnosis
found in the service documentation.
Most Scan Tools, such as the Tech 2, have data-capturing
capabilities that can assist in detecting intermittents.
No Trouble Found
This condition exists when the vehicle is found to operate
normally. The condition described by the customer may
be normal. Verify the customer complaint against another
vehicle that is operating normally. The condition may be
intermittent. Verify the complaint under the conditions
described by the customer before releasing the vehicle.
1. Re-examine the complaint.
When the complaint cannot be successfully found or
isolated, a re-evaluation is necessary. The complaint
should be re-verified and could be intermittent as
defined in
Intermittents section, or could be normal.
2. Repair and verify.
After isolating the cause, the repairs should be made.
Validate for proper operation and verify that the
symptom has been corrected. This may involve road
testing or other methods to verify that the complaint
has been resolved under the following conditions:

Conditions noted by the customer.

If a DTC was diagnosed, verify a repair by
duplicating conditions present when the DTC was
set as noted in the Failure Records or Freeze
Frame data.
Verifying Vehicle Repair
Verification of the vehicle repair will be more
comprehensive for vehicles with OBD II system
diagnostics. Following a repair, the technician should
perform the following steps:
IMPORTANT:Follow the steps below when you verify
repairs on OBD II systems. Failure to follow these steps
could result in unnecessary repairs.
1. Review and record the Failure Records and the
Freeze Frame data for the DTC which has been
diagnosed (Freeze Frame data will only be stored for
an A or B type diagnostic and only if the MIL(ºCheck
Engineº lamp) has been requested).
2. Clear the DTC(S).
3. Operate the vehicle within conditions noted in the
Failure Records and Freeze Frame data.
4. Monitor the DTC status information for the DTC which
has been diagnosed until the diagnostic test
associated with that DTC runs.
General Service Information
OBD II Serviceablity Issues
With the introduction of OBD II diagnostics across the
entire passenger car and light-duty truck market in 1996,
illumination of the MIL (ªCheck Engineº lamp) due to a
non-vehicle fault could lead to misdiagnosis of the
vehicle, increased warranty expense and customer

6E±44
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Not Run Since Code Cleared
This option will display up to DTCs that have not run since
the DTCs were last cleared. Since any displayed DTCs
have not run, their condition (passing or failing) is
unknown.
Test Failed Since Code Cleared
This selection will display all active and history DTCs that
have reported a test failure since the last time DTCs were
cleared. DTCs that last failed more than 40 warm-up
cycles before this option is selected will not be displayed.
Miscellaneous Test
This test consists of eight menus-Lights, Relays, EVAP,
Fuel System, Instruments, EGR Control, Variable Intake
Manifold Solenoid, and Injector Balance Tests.
In these tests, Tech 2 sends operating signals to the
systems to confirm their operations thereby to judge the
normality of electric circuits.
To judge intermittent trouble,
1. Confirm DTC freeze frame data, and match the
freeze frame data as test conditions with the data list
displayed by Miscellaneous Test.
2. Confirm DTC setting conditions, and match the
setting conditions as test conditions with the data list
displayed by Miscellaneous Test.
3. Refer to the latest Service Bulletin.
Check to see if the Latest software is released or not.
Down load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.
Lamps Test
This test is conducted check MIL, Up Shift Lamp, Low
Fuel Lamp, Reduced Power Lamp and Cruise Control
Lamp for its working.
Tech2 must be used for this test.
Test Procedure:
1. Connect Tech 2 to the vehicle DLC.
2. Run the Engine at idle.
3. Select F3: Miscellaneous Test in the Application
Menu.
060R100078
4. Select F0:Lamps Test in the Miscellaneous Test.
060RY00080
5. Select F0:Malfunction Indicator Lamp.
060RY00091
6. PushºOnº soft key.
7. Make sure Lamp illuminates.
8. If lamp illuminates, the Lamp is operating correctly.

6E±79
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
3.5L V-6 Engine (Automatic and Manual Transmission)
Tech 2
Parameter
Data ListUnits DisplayedTypical Data
Values (IDLE)Typical Data
Values
(2500 RPM)Refer To
A/C Clutch
RelayEngineOn/OffOffOffGeneral Description and
Operation, A/C Clutch
Circuit Operation
A/C RequestEngineYes/NoNoNoGeneral Description and
Operation, A/C Request
Signal
Air/Fuel RatioEngineRatio: _ to 114.714.7General Description and
Operation, Fuel System
Metering Purpose
APP Sensor1EnginePercent11±1335±40General Description and
Operation
APP Sensor2EnginePercent87±8860±65General Description and
Operation
APP Sensor3EnginePercent87±8850±57General Description and
Operation
Barometric
PressureEnginekPa61-104
(depends on
altitude and
barometric
pressure)61-104
(depends on
altitude and
barometric
pressure)General Description and
Operation
Brake Light
SwitchEngineOpen 0V/Closed
12VOpen 0VOpen 0VRefer to Section 5
Check Trans
Lamp (Auto
Trans)EngineOn/OffOffOff4L30-E Automatic
Transmission Diagnosis
Cruise Main
SwitchEngineActive/InactiveInactiveInactiveRefer to Section 10
Cruise Set
SwitchEngineActive/InactiveInactiveInactiveRefer to Section 10
Cruise Cancel
SwitchEngineActive/InactiveInactiveInactiveRefer to Section 10
Cruise
Resume
SwitchEngineActive/InactiveInactiveInactiveRefer to Section 10
Decel Fuel
CutoffEngineActive/InactiveInactiveInactiveGeneral Description and
Operation, Deceleration
Mode
Desired EGR
PositionEnginePercent0%0%General Description and
Operation, EGR Pintle
Position Sensor
Desired Idle
SpeedEngineRPM750800General Description and
Operation
ECT (Engine
Coolant Temp)EngineDegrees C,
Degrees F80-100
C
(176-212
F)80-100
C
(176-212
F)General Description and
Operation, Engine
Coolant Temperature
(ECT) Sensor
EGR Closed
Pintle PositionEngineSteps20-4020-40General Description and
Operation, EGR Pintle
Position Sensor

6E±84
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Malfunction Indicator Lamp (MIL)
060R200049
Circuit Description
The ªCheck Engineº lamp (MIL) should always be
illuminated and steady with the ignition ªONº and the
engine stopped. Ignition feed voltage is supplied to the
MIL bulb through the meter fuse. The powertrain control
module (PCM) turns the MIL ªONº by grounding the MIL
driver circuit.
Diagnostic Aids
An intermittent MIL may be cased by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation. Check for the following items:

Inspect the PCM 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 MILº 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
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.
12.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.
17.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
Powertrain Control Module (PCM) and Sensors.

6E±85
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Malfunction Indicator Lamp (MIL)

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Attempt to start the engine.
Does the engine start?
ÐGo to Step 3Go to Step 6
3Check the meter fuse for the instrument cluster ignition
feed circuit.
Is the fuse OK?
ÐGo to Step 4Go to Step 16
4Ignition ªONº, probe the ignition feed circuit at the
cluster connector with a test light to ground.
Is the test light ªONº?
ÐGo to Step 5Go to Step 13
51. Ignition ªOFFº.
2. Disconnect the PCM.
3. Jumper the MIL driver circuit at the PCM connector
to ground.
4. Ignition ªONº.
Is the MIL ªONº?
ÐGo to Step 10Go to Step 11
6Check the PCM ignition feed and battery feed fuses (15
A engine fuse and 15 A PCM fuse).
Are both fuses OK?
ÐGo to Step 7Go to Step 15
71. Ignition ªOFFº.
2. Disconnect the PCM.
3. Ignition ªONº.
4. Probe the ignition feed circuit at the PCM harness
connector with a test light to ground.
Is the test light ªONº?
ÐGo to Step 8Go to Step 12
8Probe the battery feed circuit at the PCM harness
connector with a test light to ground.
Is the test light ªONº?
ÐGo to Step 9Go to Step 14
9Check for a faulty PCM ground connection.
Was a problem found?
ÐVerify repairGo to Step 10
10Check for damaged terminals at the PCM.
Was a problem found?
ÐVerify repairGo to Step 17
11Check for an open MIL driver circuit between the PCM
and the MIL.
Was a problem found?
ÐVerify repairGo to Step 18
12Substitute a known ªgoodº relay for the PCM main
relay.
Was the malfunction fixed?
ÐVerify repairGo to Step 13
13Repair the open in the ignition feed circuit.
Is the action complete?
ÐVerify repairÐ
14Locate and repair the open PCM battery feed circuit.
Is the action complete?
ÐVerify repairÐ

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±90
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Reduced Power Lamp (RPL)

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
Performed?
ÐGo to Step 2
Go to OBD
System
Check
2Attempt to start the engine.
Does the engine start?
ÐGo to Step 3Go to Step 11
3Check the following fuses:
MAIN(100A), B+1(60A), B+2(50A), METER(15A),
ECM(15A) , ENGINE(15A)
Was a problem found?
ÐGo to Step 14Go to Step 4
41. Ignition ºOFFº.
2. Disconnect the cluster meter connector.
3. Ignition ªONº, Probe the ignition feed circuit at the
cluster connector with a test light to ground.
Is the test light ªONº?
ÐGo to Step 5Go to Step 15
51. Ignition ªOFFº.
2. Disconnect the Multiplex Control Unit.
3. Check the circuit (Lamp driver Circuit) between
PCM and Multiplex Control Unit.
Was a problem found?
ÐGo to Step 16Go to Step 6
61. Reconnect the cluster meter connector.
2. Disconnect the Multiplex Control Unit.
3. Jumper the RPL driver circuit at the Multiplex
Control Unit connector to ground.
4. Ignition ªONº.
Is the RPL ªONº?
ÐGo to Step 7
Go to
Instrument
Panel in
Electrical
Diagnosis
71. Ignition ªOFFº.
2. Probe the ignition feed circuit at the Multiplex
Control Unit connector with a test light to ground.
3. Ignition ªONº.
Is the test light ªONº?
ÐGo to Step 8Go to Step 17
81. Ignition ªOFFº.
2. Disconnect the PCM.
3. Check the circuit (Lamp driver Circuit) between
PCM and Multiplex Control Unit.
Was a problem found?
ÐGo to Step 18Go to Step 9
9Check the Multiplex Control Unit ground connection
and circuit.
Was a problem found?
ÐGo to Step 19Go to Step 10
10Check for damaged terminals at the Multiplex Control
Unit.
Was a problem found?
ÐGo to Step 20Go to Step 11
111. Ignition ªONº.
2. Probe the ignition feed circuit at the PCM harness
connector with a test light to ground.
Is the test light ªONº?
ÐGo to Step 12Go to Step 21