2002 ISUZU AXIOM low oil pressure

6E±71
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Injector Coil Test Procedure (Steps 1-6) and Injector Balance Test Procedure
(Steps 7-11)

 
StepNo Ye s Value(s) Action
51. Set injector switch box injector #1.
2. Press the ªPush to Start Testº button on the fuel
injector tester.
3. Observe the voltage reading on the DVM.
IMPORTANT:The voltage reading may rise during the
test.
4. Record the lowest voltage observed after the first
second of the test.
5. Set the injector switch box to the next injector and
repeat steps 2, 3, and 4.
Did any fuel injector have an erratic voltage reading
(large fluctuations in voltage that did not stabilize) or a
voltage reading above the specified value?
9.5 VGo to Step 4Go to Step 6
61. Identify the highest voltage reading recorded (other
than those above 9.5 V).
2. Subtract the voltage reading of each injector from
the highest voltage selected in step 1. Repeat until
you have a subtracted value for each injector.
For any injector, is the subtracted Value in step 2
greater than the specified value?
0.6 VGo to Step 4Go to Step 7
7CAUTION: In order to reduce the risk of fire and
personal injury, wrap a shop towel around the
fuel pressure connection. The towel will absorb
any fuel leakage that occurs during the
connection of the fuel pressure gauge. Place the
towel in an approved container when the
connection of the fuel pressure gauge is
complete.
1. Connect the J 34730-1 Fuel Pressure Gauge to the
fuel pressure test port.
2. Energize the fuel pump using the Tech 2.
3. Place the bleed hose of the fuel pressure gauge into
an approved gasoline container.
4. Bleed the air out of the fuel pressure gauge.
5. With the fuel pump running, observe the reading on
the fuel pressure gauge.
Is the fuel pressure within the specified values?
296-376 kPa
(43-55 psi)
Go to Step 8
Go to Fuel
System
Diagnosis
8Turn the fuel pump ªOFFº.
Does the fuel pressure remain constant?
ÐGo to Step 9
Go to Fuel
System
Diagnosis

6E±72
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Injector Coil Test Procedure (Steps 1-6) and Injector Balance Test Procedure
(Steps 7-11)

 
StepNo Ye s Value(s) Action
91. Connect the J 39021-5V Fuel Injector Tester and J
39021-90 Injector Switch Box the fuel injector
harness connector.
2. Set the amperage supply selector switch on the fuel
injector tester to the ªBalance Testº 0.5±2.5 amp
position.
3. Using the Tech 2 turn the fuel pump ªONº then
ªOFFº in order to pressurize the fuel system.
4. Record the fuel pressure indicated by the fuel
pressure gauge after the fuel pressure stabilizes.
This is the first pressure reading.
5. Energize the fuel injector by depressing the ªPush
to Start Testº button on the fuel injector tester.
6. Record the fuel pressure indicated by the fuel
pressure gauge after the fuel pressure gauge
needle has stopped moving. This is the second
pressure reading.
7. Repeat steps 1 through 6 for each fuel injector.
8. Subtract the second pressure reading from the first
pressure reading for one fuel injector. The result is
the pressure drop value.
9. Obtain a pressure drop value for each fuel injector.
10.Add all of the individual pressure drop values. This
is the total pressure drop.
11. Divide the total pressure drop by the number of fuel
injectors. This is the average pressure drop.
Does any fuel injector have a pressure drop value that
is either higher than the average pressure drop or lower
than the average pressure drop by the specified value?
10 kPa
(1.5 psi)
Go to Step 10
Go to OBD
System
Check
10Re-test any fuel injector that does not meet the
specification. Refer to the procedure in step 9.
NOTE: Do not repeat any portion of this test before
running the engine in order to prevent the engine from
flooding.
Does any fuel injector still have a pressure drop value
that is either higher than the average pressure drop or
lower than the average pressure drop by the specified
value?
10 kPa
(1.5 psi)
Go to Step 11
Go to
Symptoms
11Replace the faulty fuel injector(s). Refer to Fuel
Injector.
Is the action complete?ÐVerify repairÐ

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±102
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Circuit Description
The electronic Ignition system uses a coil -at-plug method
of spark distribution. In this type of ignition system, the
powertrain control module (PCM) triggers the correct
driver outside the Ignition Current Sense System (ICSS),
which then triggers the correct ignition coil based on the
58X signal received from the crankshaft position sensor
(CKP). The spark plug connected to the coil fires when
the ICSS opens the ground circuit for the coil's primary
circuit.
During crank, the PCM monitors the CKP 58X signal. The
CKP signal is used to determine which cylinder will fire
first. After the CKP 58X signal has been processed by the
PCM, it will command all six injectors to allow a priming
shot of fuel for all the cylinders. After the priming, the
injectors are left ªOFFº during the next six 58X reference
pulses from the CKP. This allows each cylinder a chance
to use the fuel from the priming shot. During this waiting
been received by the PCM. The ION sensor signal allows
the PCM to operate the injectors sequentially based on
camshaft position. If the camshaft position signal is not
present at start - up, the PCM will begin sequential fuel
delivery with a 1 -in-6 chance that fuel delivery is correct.
The engine will run without a ION sensor signal, but will
set a DTC code.
Diagnostic Aids
An intermittent problem 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.

Faulty engine coolant temperature sensor-Using a
Tech 2, compare engine coolant temperature with
intake air temperature on a completely cool engine.
Engine coolant temperature should be within 10
C of
intake air temperature. If not, replace the ECT sensor.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
5. An obvious cause of low fuel pressure would be an
empty fuel tank.
6. The engine will easily start and run if a few injectors
are disabled. It is not necessary to test all injectors
at this time since this step is only a test to verify that
all of the injectors have not been disabled by fuel
contamination.
7. A blinking test light verifies that the PCM is
monitoring the 58X crankshaft reference signal and
is capable of activating the injectors. If there is an
open or shorted driver circuit, DTCs 201 ± 206 and
a misfire DTC 300 ± 306 should be set.
19. By using a spark tester, each ignition coil's ability to
produce 25,000 volts is verified.
25. If there is an open or shorted driver circuit, DTCs
201 ± 206 and a misfire DTC 301 ± 306 should be
set. All six injector driver circuits can be checked at
one time without removing the intake manifold if a J
39021 ± 95 test light is available. This is the
alternative procedure:

With the ignition ªOFFº, disconnect the gray
connector located at the rear of the air filter, attached
to a bracket on the purge canister.

Connect test light J 39021 ± 95 to the connector. Do
any of the light constantly illuminate or fail to blink
when the engine is cranked? If so, repair the short or
open circuit, or replace the PCM if indicated.
This procedure only tests the driver circuit as far as the
test connection, so step 31 is added to test the circuit all
the way to the injector.
Engine Cranks But Will Not Run

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Check the ignition coil fuse, the engine fuse, and the
PCM fuse.
Was a fuse blown?
ÐGo to Step 3Go to Step 4
3Check for a short to ground and replace the fuse.
Is the action complete?
ÐVerify repairÐ

6E±131
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0101 MAF System Performance
060R200052
Circuit Description
The mass air flow (MAF) sensor measures the amount of
air which passes through it into the engine during a given
time. The powertrain control module (PCM) uses the
mass air flow information to monitor engine operating
conditions for fuel delivery calculations. A large quantity
of air entering the engine indicates an acceleration or high
load situation, while a small quantity or air indicates
deceleration or idle.
The MAF sensor produces a frequency signal which can
be monitored using a Tech 2. The frequency will vary
within a range of around 4 to 7g/s at idle to around 25 to
40g/s at maximum engine load. DTC P0101 will be set if
the signal from the MAF sensor does not match a
predicted value based on throttle position and engine
RPM.
Conditions for setting the DTC

The engine is running.

No TP sensor and MAP sensor DTCs are set.

No MAF frequency DTCs are set.

System voltage is between 11.5 volts and 16 volts.
Action Taken When the DTC Sets

The PCM will ON the MIL after second trip with
detected fault.

The PCM calculates an air flow value based on idle air
control valve position, throttle position, RPM and
barometric pressure.
The PCM will store condition which were present when
the DTC was set as Freeze Frame and in the Failure
Records data.
Conditions for Clearing the MIL/DTC

The PCM will turn the MIL ªOFFº on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.

A history DTC P0101 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

DTC P0101 can be cleared using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
An intermittent may be caused by the following:

Poor connections.

Misrouted harness.

Rubbed through wire insulation.

Broken wire inside the insulation.

The duct work at the MAF sensor for leaks.

An engine vacuum leak.

The PCV system for vacuum leaks.

An incorrect PCV valve.

The engine oil dip stick not fully seated.

The engine oil fill cap loose or missing.
Check for the following conditions:

6E±256
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0300 Engine Misfire Detected
Circuit Description
Misfire is monitored as a function of the combustion
quality (CQ) signals generated from the ION Sensing
Module. Combustion signals represent the degree of
combustion in each cylinder. Misfire is detected when the
combustion signal is below a predetermined value.
This DTC P0300 will determine if a multiple cylinder
misfire is occurring by monitoring the Combustion
Quality.
Conditions for Setting the DTC

None of the following DTCs occur: TP sensor, MAF
sensor, VSS, ECT sensor.

The engine speed is between 600 and 6250 RPM.

The system voltage is between 11 and 16 volts.

The engine temperature sensor (ECT) indicates an
engine temperature between ±7
C (20
F) and 110
C
(230
F).

Throttle angle is steady and throttle changes less than
2% per 125 milliseconds.
Action Taken When the DTC Sets

The PCM will ON the MIL after second trip with
detected the fault.

If the misfire is severe enough to cause possible
catalyst damage, the PCM will flash the MIL for as long
as the misfire remains at catalyst damaging levels.

The PCM will disable the TCC operation.

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC

The PCM will turn the MIL ªOFFº on the third
consecutive trip cycle in which the diagnostic has been
run and the fault condition is no longer present.

A history DTC P0300 will clear after 40 consecutive
warm-up cycles occur without a fault.

DTC P0300 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
The Tech 2 display ªMisfire Cur. #1 through #6º can be
useful to determine whether the misfire is isolated to a
single cylinder.
Damaged or faulty ignition coil ± Check for cracks or
other damage.

Substitute a known good coil ± Swap the ignition coils
and retest. If the misfire follows the coil, replace the
ignition coil.
If the misfire is random, check for the following conditions:

System grounds ± Ensure all connections are clean
and properly tightened.

MAF ± A mass air flow (MAF) sensor output that
causes the PCM to sense a lower than normal air flow
will cause a lean condition.

Air induction system ± Air leaks into the induction
system which bypass the MAF sensor will cause a lean
condition. Check for disconnected or damaged
vacuum hoses, incorrectly installed or faulty PCV
valve, or for vacuum leaks at the throttle body, EGR
valve, and intake manifold mounting surfaces.

Fuel pressure ± Perform a fuel system pressure test.
A faulty fuel pump, plugged filter, or faulty fuel system
pressure regulator will contribute to a lean condition.

Injector(s) ± Perform an injector coil/balance test to
locate faulty injector(s) contributing to a lean or
flooding condition. In addition to the above test, check
the condition of the injector O-rings.

EGR ± Check for a leaking valve, adapter, or feed pipes
which will contribute to a lean condition or excessive
EGR flow.

Fuel quality ± Using fuel with the wrong octane rating
for the vehicle may cause driveability problems.
Although alcohol-enhanced fuels may raise the octane
rating, the fuel's ability to turn into vapor in cold
temperatures deteriorates. This may affect the cold
driveability of the engine. The Reid Vapor Pressure of
the fuel can also create problems in the fuel system,
especially during the spring and fall when changes by
the refineries may not coincide with changes in the
weather.

Vehicle marshalling ± The transportation of new
vehicles from the assembly plant to the dealership can
involve as many as 60 key cycles within 2 to 3 miles of
driving. This type of operation contributes to the fuel
fouling of the spark plugs and will turn on the MIL with
a P0300 Misfire DTC.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.

6E±258
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0300 ± Engine Misfire Detected

 
StepNo Ye s Value(s) Action
81. Install a spark tester at the spark plug end of the
ignition coil for a cylinder that indicated a misfire.
2. Crank the engine while observing the spark tester.
A crisp, blue spark should be observed.
Is adequate spark present?
ÐGo to Step 14Go to Step 9
91. Remove and visually/physically inspect the ignition
coil(s) associated with the cylinders that were
indicated as misfiring. Ensure that the coil(s) are
free of cracks.
2. If a problem is found, replace the damaged ignition
coil(s) as necessary.
Did any ignition coils require replacement?
ÐVerify repairGo to Step 10
101. Remove the spark plugs from the cylinders that
were indicated as misfiring.
2. Visually inspect the spark plug electrodes.
Does your inspection reveal any spark plugs exhibiting
excessive fouling?
Ð
Go to Engine
Mechanical
Diagnosis
Go to Step 11
111. Visually inspect the spark plug insulators for cracks,
carbon tracking, or other damage.
2. If a problem is found, replace the faulty spark
plug(s) as necessary.
Did your inspection reveal a problem?
ÐVerify repairGo to Step 12
121. Disconnect the MAF sensor electrical connector.
2. Operate the vehicle in ªclosed loopº while
monitoring the ªBANK 1 L.T. FUEL TRIMº and
ªBANK 1 S.T. FUEL TRIMº display on the Tech 2.
Do both values decrease below the specified values?ºBANK 1 L.T.
FUEL TRIMº
below +20%;
ªBANK 1 S.T.
FUEL TRIMº
below +50%
Go to Step 13
Replace the
ignition coil of
the affected
cylinder
13Replace the ignition coil control module.
Is the action complete?
ÐVerify repairÐ
141. Visually and physically inspect the PCM injector
grounds, power grounds and sensor grounds to
ensure that they are clean, tight and in their proper
locations.
2. If a problem is found, correct the faulty ground
condition as necessary.
Did your inspection reveal a poor ground?
ÐVerify repair Go to Step 15
151. Perform the ªFuel System Pressure Testº
procedure.
2. If a problem is found, repair as necessary (refer to
Engine Fuel or Fuel Metering System).
Was a fuel system problem found?
ÐVerify repairGo to Step 16
161. Check the fuel for excessive water, alcohol, or other
contaminants (refer to
Diagnosis in Engine Fuel for
procedure).
2. If a problem is found, correct the contaminated fuel
condition as necessary.
Was the fuel contaminated?
ÐVerify repairGo to Step 17

6E±356
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0506 Idle Air Control System Low RPM
060R200057
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 position (%) to adjustment the throttle valve into a
passage in the throttle body to air flow. This method
allows highly accurate control of engine speed and quick
response to changes in engine load.
If the PCM detects a condition where too low of an idle
speed is present and the PCM is unable to adjust idle
speed by increasing the throttle position, DTC P0506 will
set, indicating a problem with the idle control system.
Conditions for Setting the DTC

No TPS, VSS, ECT, EGR, MAF, MAP, IAT, low voltage,
fuel system, canister purge, injector control, or ignition
control DTCs are set.

MAP is less than 60 kPa.

Canister purge duty cycle is above 10%.

Engine running time is more than 125 seconds.

Vehicle speed is less than 1 mph.

Engine coolant temperature (ECT) is above 50
C
(122
F).

Ignition voltage is between 9.5 volts and 16.7 volts.

The throttle is closed.

EVAP purge duty cycle more than 10%.

All conditions are met for 10 seconds.

Barometric pressure is more than 74.5 kPa.
Engine speed is more than 100-200 RPM lower than
desired idle based upon coolant temperature.
Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
fault is detected.

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC

DTC P0506 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:

Poor connection at PCM or throttle DC motor ± Inspect
harness connectors for backed-out terminals,
improper mating, broken locks, improperly formed or
damaged terminals, and poor terminal-to-wire
connection.

Damaged harness ± Inspect the wiring harness for
damage.

Restricted air intake 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 ETC
passage or throttle bore, excessive deposits in the