engine ISUZU AXIOM 2002 Service Repair Manual

6E±103
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Engine Cranks But Will Not Run

 
StepNo Ye s Value(s) Action
41. Ignition ªOFFº, install a fuel pressure gauge at the
test fitting on the fuel supply line in the engine
compartment. (Use a shop cloth to absorb any fuel
leakage while making the connection.)
2. Ignition ªONº, observe the fuel pressure.
Is the fuel pressure within the specified values, and
does it hold steady?
285 - 375 kPa
(43 ± 55 psi)
Go to Step 6Go to Step 5
5Is any fuel pressure indicated?
Ð
Go to Fuel
System
Electrical TestGo to Fuel
System
Diagnosis
6Install the switch box J 39021±2 at the injector test
connector and activate an injector.
Did the fuel pressure drop when the injector was
activated?
ÐGo to Step 7Go to Step 18
7Install an injector test light at the #2 cylinder injector
harness connector.
Does the light blink when the engine is cranked?
ÐGo to Step 8Go to Step 24
81. Ignition ª OFFº.
2. Disconnect the 11-pin connector at the ION sensing
module.
3. With a test light to B + , probe each of the 6 exposed
ION sensing module pins, one at a time, while the
engine is cranked. (Use the gray narrow Metri - Pak
W flexible female connector from the J - 35616 kit to
make the pin accessible.)
Does the light flash at each pin when the engine is
cranked?
ÐGo to Step 12Go to Step 9
91. Remove the 4-pin connector at the ION sensing
module.
2. Ignition ª ONº.
3. Use a test light at the harness connector to verify
that the module is being supplied with B + and
ground.
Was a problem found?
ÐGo to Step 10Go to Step 11
10Repair the open ignition feed circuit or ground circuit to
the ION sensing module.
Is the action complete?
ÐVerify repairÐ
11Repair the ION sensing module.
Is the action complete?
ÐVerify repairÐ
121. Reconnect the ION sensing module 11-pin
connector.
2. Remove the electrical connector from each coil.
3. With a test light to B+, probe each of the coil
connectors at the wire which runs to the ION
sensing module.
Does the light flash at each coil connector when the
engine is cranked?
ÐGo to Step 14Go to Step 13
13Check for an open circuit between the coil and ION
sensing module.
Is the action complete?
ÐVerify repairÐ

6E±104
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Engine Cranks But Will Not Run

 
StepNo Ye s Value(s) Action
141. Ignition ªONº.
2. While the coil connectors are disconnected, touch
each coil connector's ignition feed terminal with a
grounded test light (the ignition feed wire is YEL
tracer).
Did the test light illuminate?
ÐGo to Step 16Go to Step 15
15Repair the open ignition feed circuit.
Is the action complete?
ÐVerify repairÐ
16While the coil connectors are disconnected, touch
each connector's secondary ground terminal with a
test light to B +. (The ground wires are black.)
Did the test light illuminate at each coil connector?
ÐGo to Step 18Go to Step 17
17Repair the open secondary ground circuit.
Is the action complete?
ÐVerify repairÐ
181. Test the fuel for contamination.
2. If a problem is found, clean the fuel system and
correct the contaminated fuel condition as
necessary. Replace the fuel filter and replace any
injectors that are not delivering fuel (see Injector
Balance Test).
Was a problem found?
ÐVerify repairGo to Step 19
191. Remove any ignition coil and install a spark tester at
the spark plug end of the coil.
2. Observe the tester while the engine is cranking.
Was a crisp, blue spark observed? Only one or two
sparks followed by no result is considered the same as
ªNo Sparkº.
ÐGo to Step 21Go to Step 20
20Replace the ignition coil, and return to Step 19 to test
the remaining coils.
Is the action complete?
ÐVerify repairÐ
21Repeat Step 19 for each coil. Remove only one coil at a
time, and reinstall each coil on its spark plug after
testing, but do not refasten coils with screws at this
time.
After all coils have passed the spark test, does the
engine start?
Ð
Refasten all
coils with
their screws
Go to Step 22
221. Remove the spark plugs from all cylinders.
2. Visually inspect the spark plug electrodes.
3. Replace any spark plugs with loose or missing
electrodes or cracked insulators.
Did your inspection reveal any spark plugs exhibiting
excessive fouling?
Ð
Correct the
fouling
condition
Go to Step 23

6E±105
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Engine Cranks But Will Not Run

 
StepNo Ye s Value(s) Action
23Refer to Engine Mechanical Diagnosis to diagnose the
following conditions:

Faulty or incorrect camshaft drive belts

Leaking or sticky valves or rings

Excessive valve deposits

Weak valve springs

Incorrect valve timing

Leaking head gasket
Is the action complete?
ÐVerify repairGo to Step 25
24Observe the ªEngine Speedº data display on the Tech 2
while cranking the engine.
Is the engine RPM indicated?
ÐGo to Step 25Go to Step 34
251. Disconnect the 7-pin gray connector at the rear of
the air filter beneath the point where the air duct
attaches to the MAF sensor.
2. Ignition ªONº.
3. Using a test light connected to ground, probe the
ignition terminal at the PCM (female) side of the
7-pin connector.
Is the test light ªONº?
ÐGo to Step 26Go to Step 32
261. At the PCM (female) side of the connector, connect
a test light between the ignition + terminal and one
of the injector driver circuits at the same connector.
2. Ignition ªONº.
3. Observe the test light, and repeat the test for each
injector driver circuit.
Did the test light stay on when checking any of the 6
injector driver circuits?
ÐGo to Step 27Go to Step 29
271. Ignition ªOFFº, disconnect the PCM.
2. Ignition ªONº, observe the test light.
Is the test light ªONº?
ÐGo to Step 28Go to Step 33
28Locate and repair the short to ground in the injector
driver circuit.
Is the action complete?
ÐVerify repairÐ
291. Using the same test location as in step 26, connect
a test light between the ignition terminal and one of
the driver circuits.
2. Crank the engine and observe the test light.
3. Repeat for each injector driver circuit.
Did the light blink during the test for each circuit?
ÐGo to Step 31Go to Step 30
30Check for an open injector driver circuit.
Was a problem found?
ÐVerify repairGo to Step 33

6E±106
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Engine Cranks But Will Not Run

 
StepNo Ye s Value(s) Action
311. At the injector (male) side of the gray connector
mentioned in step 25, connect an ohmmeter
between the ignition pin and one of the driver circuit
pins.
2. Check for continuity in the circuit.
3. Repeat for each injector circuit. The readings
should be approximately equal to the specified
value for injector resistance.
Was a problem found?
12.5
Verify repairGo to Step 8
32Repair the ignition feed circuit.
Is the action complete?
ÐVerify repairÐ
33Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed.
Refer to
ON-Vehicle Service in Power Control Module
and Sensors 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
341. Raise the vehicle and disconnect the CKP sensor
harness.
2. Ignition ªONº.
3. With a test light to ground, probe the harness
ignition feed terminal.
Did the light illuminate?
ÐGo to Step 36Go to Step 35
35Check the ignition feed wire between the sensor and
the PCM for a short to ground or open circuit.
Is the action complete?
ÐVerify repairÐ
361. Ignition ªONº.
2. At the CKP harness connector, connect a test light
between the ignition and ground terminals.
Did the light illuminate?
ÐGo to Step 38Go to Step 37
37Check the sensor ground circuit for an open or short to
voltage.
Is the action complete?
ÐVerify repairÐ
38Check the signal circuit between the sensor and the
PCM for a short to ground, short to voltage, or an open.
Was a problem found?
ÐVerify repairGo to Step 39
39Replace the CKP position sensor.
Is the action complete?
ÐVerify repairGo to Step 33

6E±107
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Fuel System Electrical Test
060R200044

6E±108
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Circuit Description
When the ignition switch is first turned ªONº, the
powertrain control module (PCM) energizes the fuel
pump relay which applies power to the in-tank fuel pump.
The fuel pump relay will remain ªONº as long as the
engine is running or cranking and the PCM is receiving
58X crankshaft position pulses. If no 58X crankshaft
position pulses are present, the PCM de-energizes the
fuel pump relay within 2 seconds after the ignition is
turned ªONº or the engine is stopped.
The fuel pump delivers fuel to the fuel rail and injectors,
then to the fuel pressure regulator. The fuel pressure
regulator controls fuel pressure by allowing excess fuel to
be returned to the fuel tank. With the engine stopped and
ignition ªONº, the fuel pump can be turned ªONº by using a
command by the Tech 2.
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 fuel pump is operating but incorrect pressure is
noted, the fuel pump wiring is OK and the ªFuel
System Pressure Testº chart should be used for
diagnosis.
CAUTION: To reduce the risk of fire and personal
injury:

It is necessary to relieve fuel system pressure
before connecting a fuel pressure gauge. Refer to
Fuel Pressure Relief Procedure, below.

A small amount of fuel may be released when
disconnecting the fuel lines. Cover fuel line
fittings with a shop towel before disconnecting, to
catch any fuel that may leak out. Place the towel in
an approved container when the procedure is
completed.
Fuel Pressure Relief Procedure
1. Remove the fuel cap.
2. Remove the fuel pump relay from the underhood
relay center.
3. Start the engine and allow it to stall.
4. Crank the engine for an additional 3 seconds.
Fuel Gauge Installation
1. Remove the shoulder fitting cap.
2. Install fuel gauge J 34730-1 to the fuel feed line
located in front of and above the right side valve train
cover .
3. Reinstall the fuel pump relay.

6E±109
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Fuel System Electrical Test

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Read the ªCautionº above.
2. Relieve the fuel system pressure and install the fuel
pump pressure gauge to the test fitting.
3. Ignition ON, Engine is Off.
4. Use a Tech 2 to command the fuel pump ªONº.
(Refer to the Miscellaneous Test.)
Is there an immediate pressure build-up which
indicates the pump is running?
ÐGo to Step 3Go to Step 4
31. Verify that the pump is not running by removing the
fuel filler cap and listening.
2. Command the pump ªONº with the Tech 2.
Did the pump turn ªOFFº after 2 seconds?
Ð
Test
completed
Go to Step 12
41. Ignition ªOFFº.
2. Remove the fuel pump relay.
3. Using a test light connected to ground, probe the
battery feed to the relay.
Did the light illuminate?
ÐGo to Step 6Go to Step 5
5Repair short or open battery feed to fuel pump relay.
Is the action complete?
ÐVerify repairÐ
61. Connect a test light between the two wires that
connect to the fuel pump relay pull-in coil.
2. Ignition ªONº.
Did the test light illuminate for 2 seconds and then turn
off?
ÐGo to Step 12Go to Step 7
71. With a test light connected to battery (±), probe the
fuel pump relay connector at the wire which runs
from the relay pull-in coil to the PCM.
2. Ignition ªONº.
Did the test light illuminate for 2 seconds and then turn
off?
ÐGo to Step 8Go to Step 9
8Locate and repair open in the fuel pump relay ground
circuit.
Is the action complete?
ÐVerify repairÐ
9Check for short or open between the PCM and the fuel
pump relay.
Was a problem found?
ÐVerify repairGo to Step 10
101. Check the fuel pump relay circuit for a poor terminal
connection at the PCM.
2. If a problem is found, replace terminal as necessary.
Was a problem found?
ÐVerify repairGo to Step 11

6E±110
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Fuel System Electrical Test

 
StepNo Ye s Value(s) Action
11Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
On-Vehicle Service in
Powertrain Control Module and Sensors 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
121. Reconnect the fuel pump relay.
2. Disconnect the fuel pump electrical connector at the
fuel tank.
3. Using a test light connected to ground, probe the
fuel pump feed wire (harness side).
4. Command the fuel pump ªONº with a Tech 2.
Did the light illuminate for 2 seconds?
ÐGo to Step 15Go to Step 13
131. Honk the horn to verify that the horn relay is
functioning.
2. Substitute the horn relay for the fuel pump relay.
3. Leave the test light connected as in step 12.
4. Command the fuel pump ªONº with the Tech 2.
Did the test light illuminate for 2 seconds when the fuel
pump was commanded ªONº?
ÐGo to Step 17Go to Step 14
141. Re-connect the horn relay in its proper location.
2. Check for a short circuit, blown fuse or open circuit
between the relay and the fuel tank.
Is the action complete?
ÐVerify repairÐ
151. With the fuel pump electrical connector at the fuel
tank disconnected, connect a test light between the
feed wire and the ground wire (harness side).
2. Command the fuel pump ªONº with a Tech 2.
Did the test light illuminate for 2 seconds?
ÐGo to Step 18Go to Step 16
16Repair the open circuit in the fuel pump ground wire.
Is the action complete?
ÐVerify repairÐ
171. Re-connect the horn relay in its proper location.
2. Replace the fuel pump relay.
Is the action complete?
ÐVerify repairÐ
18Replace the fuel pump.
Is the action complete?
ÐVerify repairÐ

6E±111
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Electric Throttle Control (ETC) System Check
060R200065

6E±112
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Circuit Description

The powertrain control module (PCM) controls
engine speed by adjusting the position of the throttle
control valve (DC motor). The throttle motor is a DC
motor driven by one coil. The PCM applies current to
the DC motor coil in PWM (%) to adjust the throttle
valve into a passage in the throttle body to allow air
flow. This method allows highly accurate control of
engine speed and quick response to changes in
engine load.

The accelerator position (AP1) sensor circuit
provides a voltage signal relative to accelerator pedal
angle.
The accelerator pedal angle will vary about 13% at
idle position to about 87% at wide open
throttle(WOT).
APS signal is used to determine which DC motor will
adjust throttle position.
After the APS signal has been processed by the
PCM, it will command DC motor to allow movement
of throttle position.
Diagnostic Aids

An intermittent may be caused by a poor connection,
rubbed-through wire insulation or a wire broken inside
the insulation. Check for poor connections or a
damaged harness. Inspect the PCM harness and
connector for improper mating, broken locks,
improperly formed or damaged terminals, poor
terminal-to-wire connection, and damaged harness.

Throttle body ± Check for objects blocking the DC
motor or throttle bore, excessive deposits in the ETC
passage and on the valve spring, and excessive
deposits in the throttle bore and on the throttle valve
plate.

Accelerator pedal ± Check for objects blocking the AP
sensor or pedal arm with spring, and excessive
deposits in the accelerator pedal arm and on the
accelerator pedal.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart:
2. Visually/physically inspect for the following throttle
valve conditions.
3. Visually/physically inspect for the following
accelerator pedal conditions.
5. Check the following circuits for throttle valve and DC
motor. Check the following TP sensor resistance
and DC motor.
7. Check the following circuits for accelerator pedal.
Check the following AP sensor resistance.
10. Following DTC: Software detect Error for ETC
system.
11. Following DTC: Software detect Error for ETC
system.