2002 ISUZU AXIOM ignition

6E±113
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Electric Throttle Control (ETC) System Check

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Visually/physically inspect for the following conditions:

Throttle body tampering.

Restricted intake throttle system. Check for a
possible collapsed air intake duct, restricted air
filter element, or foreign objects blocking the air
intake system.

Throttle body: Check for objects blocking the
throttle passage or throttle bore, excessive
deposits in the throttle passage and on the throttle
valve, and excessive deposits in the throttle bore
and on the throttle plate.

Throttle body with lever: When check for objects
to send round the throttle spring lever that lever is
smooth movement by less than 9 l´bm{1.0 N´m},
and spring lever has not excessive play.

Throttle function: Check for the throttle function.
When ignition switch ªONº that throttle lever is
smooth operated by step on the accelerator
pedal.
Did any of the above require a repair?
Ð
Refer to
appropriate
section for
on-vehicle
service
Go to Step 3
3Visually/physically inspect for the following conditions:

Accelerator pedal tampering.

Accelerator pedal : Check for objects blocking the
spring or pedal arm.

Accelerator pedal : For check for objects to move
the accelerator pedal that pedal is smooth
movement, and accelerator pedal arm has not
excessive play.
Did any of the above require a repair?
Ð
Refer to
appropriate
section for
on-vehicle
service
Go to Step 4
41. Check for a poor connection at the throttle body
harness connector.
2. Check for a poor connection at the accelerator
position sensor harness connector.
3. If a problem is found, replace faulty terminals as
necessary.
Was a problem found?
ÐVerify repairGo to Step 5
5Check the following circuits for an open, short to
voltage, short to ground, or poor connection at the
PCM:

Throttle position sensor 1 circuit.

Throttle position sensor 2 circuit.

Throttle DC motor circuit.

Throttle position sensor resistance.

Throttle DC motor resistance.
If a problem is found, repair as necessary.
Was a problem found?
Vcc±GND
1±7k

SIG±GND
change
resistance
0.3±100

Verify repairGo to Step 6

6E±114
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Electric Throttle Control (ETC) System Check

 
StepNo Ye s Value(s) Action
61. Install the Tech 2
2. Ignition ªONº but not engine run.
3. Chech the valve for APS and TPS.
Was the problem found?Idle AP1 =
11±13% AP2
= 87±88%
AP3 =
87±88% TP1
= 1±6% TP2
= 1±6% WOT
AP1 =
85±89% AP2
= 11±15%
AP3 =
32±36% TP1
= 98±100%
TP2 =
98±100%
Go to Step 10Go to Step 7
7Replace the throttle valve.
Is the action complete?
ÐGo to Step 8Ð
8Check the following circuits for an open, short to
voltage, short to ground, or poor connection at the
PCM:

Accelerator position sensor 1 circuit.

Accelerator position sensor 2 circuit.

Accelerator position sensor 3 circuit.

Accelerator position sensor resistance.
If a problem is found, repair as necessary.
Was a problem found?
Vcc±GND
4±6k

SIG±GND
change
resistance
Verify repairGo to Step 9
9Replace the accelerator position sensor.
Is the action complete?
ÐGo to Step 10±
10Following below the DTCs stored:
P1125, P1290, P1295, P1299
Ð
Go to
applicable
DTC chart
Go to Step 11
11Following below the DTCs stored:
P1514, P1515, P1516, P1523, P1271, P1272, P1273
Ð
Go to
applicable
DTC chart
Go to Step 12
12Replace 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

6E±116
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Circuit Description
When the ignition switch is turned ªONº, the powertrain
control module (PCM) will turn ªONº the in-tank fuel
pump. The in-tank fuel pump will remain ªONº as long as
the engine is cranking or running and the PCM is receiving
58X crankshaft position pulses. If there are no 58X
crankshaft position pulses, the PCM will turn the in-tank
fuel pump ªOFFº 2 seconds after the ignition switch is
turned ªONº or 2 seconds after the engine stops running.
The in-tank fuel pump is an electric pump within an
integral reservoir. The in-tank fuel pump supplies fuel
through an in-line fuel filter to the fuel rail assembly. The
fuel pump is designed to provide fuel at a pressure above
the pressure needed by the fuel injectors. A fuel pressure
regulator, attached to the fuel rail, keeps the fuel available
to the fuel injectors at a regulated pressure. Unused fuel
is returned to the fuel tank by a separate fuel return line.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Connect the fuel pressure gauge to the fuel feed line
as shown in the fuel system illustration. Wrap a
shop towel around the fuel pressure connection in
order to absorb any fuel leakage that may occur
when installing the fuel pressure gauge. With the
ignition switch ªONº and the fuel pump running, the
fuel pressure indicated by the fuel pressure gauge
should be 333-376 kPa (48-55 psi). This pressure
is controlled by the amount of pressure the spring
inside the fuel pressure regulator can provide.
3. A fuel system that cannot maintain a constant fuel
pressure has a leak in one or more of the following
areas:

The fuel pump check valve.

The fuel pump flex line.

The valve or valve seat within the fuel pressure
regulator.

The fuel injector(s).
4. Fuel pressure that drops off during acceleration,
cruise, or hard cornering may case a lean condition.
A lean condition can cause a loss of power, surging,
or misfire. A lean condition can be diagnosed using
a Tech 2. If an extremely lean condition occurs, the
oxygen sensor(s) will stop toggling. The oxygen
sensor output voltage(s) will drop below 500 mV.
Also, the fuel injector pulse width will increase.
IMPORTANT:Make sure the fuel system is not
operating in the ªFuel Cut-Off Modeº.
When the engine is at idle, the manifold pressure is
low (high vacuum). This low pressure (high vacuum)
is applied to the fuel pressure regulator diaphragm.
The low pressure (high vacuum) will offset the
pressure being applied to the fuel pressure regulator
diaphragm by the spring inside the fuel pressure
regulator. When this happens, the result is lower fuel
pressure. The fuel pressure at idle will vary slightly as
the barometric pressure changes, but the fuel
pressure at idle should always be less than the fuel
pressure noted in step 2 with the engine ªOFFº.16.Check the spark plug associated with a particular
fuel injector for fouling or saturation in order to
determine if that particular fuel injector is leaking. If
checking the spark plug associated with a particular
fuel injector for fouling or saturation does not
determine that a particular fuel injector is leaking,
use the following procedure:

Remove the fuel rail, but leave the fuel lines and
injectors connected to the fuel rail. Refer to
Fuel Rail
Assembly
in On-Vehicle Service.

Lift the fuel rail just enough to leave the fuel injector
nozzles in the fuel injector ports.
CAUTION: In order to reduce the risk of fire and
personal injury that may result from fuel spraying on
the engine, verify that the fuel rail is positioned over
the fuel injector ports and verify that the fuel injector
retaining clips are intact.

Pressurize the fuel system by connecting a 10 amp
fused jumper between B+ and the fuel pump relay
connector.

Visually and physically inspect the fuel injector
nozzles for leaks.
17.A rich condition may result from the fuel pressure
being above 376 kPa (55 psi). A rich condition may
cause a DTC P0132 or a DTC P0172 to set.
Driveability conditions associated with rich
conditions can include hard starting (followed by
black smoke) and a strong sulfur smell in the
exhaust.
20.This test determines if the high fuel pressure is due
to a restricted fuel return line or if the high fuel
pressure is due to a faulty fuel pressure regulator.
21.A lean condition may result from fuel pressure
below 333 kPa (48 psi). A lean condition may
cause a DTC P0131 or a DTC P0171 to set.
Driveability conditions associated with lean
conditions can include hard starting (when the
engine is cold ), hesitation, poor driveability, lack of
power, surging , and misfiring.
22.Restricting the fuel return line causes the fuel
pressure to rise above the regulated fuel pressure.
Command the fuel pump ªONº with the Tech 2. The
fuel pressure should rise above 376 kPa (55 psi) as
the fuel return line becomes partially closed.
NOTE: Do not allow the fuel pressure to exceed 414 kPa
(60 psi). Fuel pressure in excess of 414 kPa (60 psi) may
damage the fuel pressure regulator.
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.

6E±117
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
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.
Fuel System Diagnosis

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Turn the ignition ªOFFº.
2. Turn the air conditioning system ªOFFº.
3. Relieve fuel system pressure and install the fuel
pressure gauge.
4. Turn the ignition ªONº.
NOTE: The fuel pump will run for approximately 2
seconds. Use the Tech 2 to command the fuel pump
ªONº.
(Refer to the Miscellaneous Test.)
5. Observe the fuel pressure indicated by the fuel
pressure gauge with the fuel pump running.
Is the fuel pressure within the specified limits?
290-376 kPa
(42-55 psi)
Go to Step 3Go to Step 17
3NOTE: The fuel pressure will drop when the fuel pump
stops running, then it should stabilize and remain
constant.
Does the fuel pressure indicated by the fuel pressure
gauge remain constant?
ÐGo to Step 4Go to Step 12
41. When the vehicle is at normal operation
temperature, turn the ignition ªONº to build fuel
pressure and observe the measurement on the
gauge.
2. Start the engine and observe the fuel pressure
gauge.
Did the reading drop by the amount specified after the
engine was started?
21-105 kPa
(3-15 psi)
Go to Step 5Go to Step 9
5Is fuel pressure dropping off during acceleration,
cruise, or hard cornering?
ÐGo to Step 6
Check for
improper fuel
6Visually and physically inspect the following items for a
restriction:

The in-pipe fuel filter.

The fuel feed line.
Was a restriction found?
ÐVerify repairGo to Step 7
7Remove the fuel tank and visually and physically
inspect the following items:

The fuel pump strainer for a restriction.

The fuel line for a leak.

Verify that the correct fuel pump is in the vehicle.
Was a problem found in any of these areas?
ÐVerify repairGo to Step 8

6E±121
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Exhaust Gas Recirculation (EGR) System Check

StepActionValue(s)Ye sNo
1Check the EGR valve for looseness.
Is the EGR valve Loose?
ÐGo to Step 2Go to Step 3
2Tighten the EGR valve.
Is the action complete?
ÐVerify repairÐ
31. Place the transmission selector in Park or Neutral.
2. Start the engine and idle until warm.
3. Using a Tech 2, command EGR ª50% ONº.
(Refer to the Miscellaneous Test.)
Does the engine idle rough and lose RPMs?
Ð
EGR system
working
properly. No
problem
found.
Go to Step 4
41. Engine ªOFFº.
2. Ignition ªONº.
3. Using a test light to ground, check the EGR harness
between the EGR valve and the ignition feed.
Does the test light illuminate?
ÐGo to Step 6Go to Step 5
5Repair the EGR harness ignition feed.
Was the problem corrected?
ÐVerify repairGo to Step 6
61. Remove the EGR valve.
2. Visually and physically inspect the EGR valve
pintle, valve passages and adapter for excessive
deposits, obstructions or any restrictions.
Does the EGR valve have excessive deposits,
obstructions or any restrictions?
ÐGo to Step 7Go to Step 8
7Clean or replace EGR system components as
necessary.
Was the problem corrected?
ÐVerify repairGo to Step 8
81. Ground the EGR valve metal case to battery (±).
2. Using a Tech 2, command EGR ªONº and observe
the EGR valve pintle for movement.
Does the EGR valve pintle move according to
command?
ÐGo to Step 9
Go to DTC
P1406 chart
91. Remove the EGR inlet and outlet pipes from the
intake and exhaust manifolds.
2. Visually and physically inspect manifold EGR ports
and EGR inlet and outlet pipes for blockage or
restriction caused by excessive deposits or other
damage.
Do the manifold EGR ports or inlet and outlet pipes
have excessive deposits, obstructions, or any
restrictions?
ÐGo to Step 10
EGR system
working
properly. No
problem
found.
10Clean or replace EGR system components as
necessary.
Is the action complete?
ÐVerify repairÐ

6E±123
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Manifold Absolute Pressure (MAP) Output Check

StepActionValue(s)Ye sNo
11. Turn the ignition ªOFFº and leave it ªOFFº for 15
seconds.
2. Ignition ªONº. Don't crank engine.
3. The Tech 2 should indicate a manifold absolute
pressure (MAP) sensor voltage.
4. Compare this scan reading to scan reading of a
known good vehicle obtained using the exact same
procedure as in Steps 1-4.
Is the voltage reading the same +/±0.40 volt?
ÐGo to Step 2Go to Step 5
21. Disconnect the vacuum hose at the MAP sensor
and plug the hose.
2. Connect a hand vacuum pump to the MAP sensor.
3. Start the engine.
4. Apply 34 kPa (10 in.Hg) of vacuum and note the
voltage change.
Is the voltage change 1.5-2.1 volts less than Step 1?
ÐGo to Step 3Go to Step 4
3Check the sensor cover for leakage or restriction.
Does the hose supply vacuum to the MAP sensor only?
ÐGo to Step 5Go to Step 4
4Repair the hose blockage.
Is the action complete?
ÐVerify repairÐ
5Check the sensor connection.
Is the sensor connection good?
ÐGo to Step 6Go to Step 7
6Refer to On-Vehicle Service, MAP Sensor.
Is the action complete?ÐVerify repairÐ
7Repair the poor connection.
Is the action complete?
ÐVerify repairÐ

6E±125
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Evaporative (EVAP) Emissions Canister Purge Valve Check

StepActionValue(s)Ye sNo
11. Ignition ªOFFº.
2. Ignition ªONº, engine ªOFFº.
3. At the throttle body, disconnect the hose that goes
to the purge solenoid.
4. Using a hand vacuum pump with an attached
vacuum gauge J 23738-A, apply vacuum (10 in. Hg
or 34 kPa) to the solenoid.
Does the solenoid hold the vacuum?
ÐGo to Step 3Go to Step 2
21. Disconnect the solenoid electrical connector.
2. As in Step 1, apply vacuum (10 in. Hg or 34 kPa) to
the solenoid.
Does the solenoid hold the vacuum?
ÐGo to Step 4Go to Step 7
31. At the throttle body, put a cap over the vacuum port
where the hose was disconnected for testing. This
is to prevent a vacuum leak when the engine is
started.
2. Ignition ªOFFº.
3. Install the Tech 2.
4. Apply vacuum to the purge solenoid with the hand
vacuum pump.
5. Start the engine, run at 2500 RPM.
6. Using the Tech 2, select Powertrain, 3.5±V6 6VE1,
F3: Misc. Tests, F2: EVAP Purge, F0: EVAP Purge.
(Refer to the Misellaneous Test.)
7. Turn the purge solenoid ªONº.
Did the vacuum drop when the purge was turned on?
ÐGo to Step 8Go to Step 9
4Check for a short to ground in the S7 Pin wire.
Is there a short?
ÐGo to Step 5Go to Step 6
5Repair the short to ground.
Is the action complete?
ÐVerify repairÐ
6Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
On-Vehicle Servicein
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
7Replace the faulty purge solenoid. Refer to On-Vehicle
Service, EVAP Canister Purge Solenoid.
Is the action complete?ÐVerify repairÐ

6E±126
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Evaporative (EVAP) Emissions Canister Purge Valve Check

 
StepNo Ye s Value(s) Action
81. Turn the ignition ªOFFº.
2. At the throttle body, install a vacuum gauge where
the hose from the purge solenoid was disconnected
for testing.
3. Start the engine.
4. Stabilize the engine speed at about 2500 RPM.
5. Momentarily snap the throttle open and let it return
to idle.
Is there approximately 10 in. Hg (34 kPa) of vacuum
available at the EVAP emission canister purge
solenoid?
Ð
No problem
found in the
EVAP
emission
canister
purge valve
check
Refer to
Diagnostic
Aids
91. Disconnect the solenoid electrical connector.
2. Connect a test lamp between the harness
terminals.
Does the test lamp light?
ÐGo to Step 7Go to Step 10
10Probe terminal A and terminal B with a test lamp to
ground.
Does the test lamp light on both terminals?
ÐGo to Step 11Go to Step 12
11Repair the short to voltage in the S7 Pin wire.
Is the action complete?
ÐVerify repairÐ
12Does one of the terminals light the test lamp?ÐGo to Step 13Go to Step 14
13Check for an open in the S7 Pin wire between the purge
solenoid and the PCM.
Was there an open circuit?
ÐGo to Step 15Go to Step 6
14Repair the open in the BLK/YEL wire.
Is the action complete?
ÐVerify repairÐ
15Repair the open in the S7 Pin wire.
Is the action complete?
ÐVerify repairÐ