2002 ISUZU AXIOM battery

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±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±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±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±91
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
No Reduced Power Lamp (RPL)

 
StepNo Ye s Value(s) Action
121. Ignition ªOFFº.
2. Check for a faulty PCM ground connection and
Circuit.
Was a problem found?
ÐGo to Step 23Go to Step 13
13Check for damaged terminals at the PCM.
Was a problem found?
ÐGo to Step 24Go to Step 25
14Replace the fuse.
Is the action complete?
ÐVerify repairÐ
15Locate and repair the cluster meter battery feed open
circuit.
Is the action complete?
ÐVerify repairÐ
16Locate and repair the circuit between cluster meter and
Multiplex Control Unit open circuit.
Is the action complete?
ÐVerify repairÐ
17Locate and repair the circuit Multiplex Control Unit
battery feed open circuit.
Is the action complete?
ÐVerify repairÐ
18Locate and repair the between Multiplex Control Unit
and PCM open circuit.
Is the action complete?
ÐVerify repairÐ
19Locate and repair the ground connection for Multiplex
Control Unit circuit.
Is the action complete?
ÐVerify repairÐ
20Reconnect the Multiplex Control Unit. circuit.
Is the action complete?
ÐVerify repairÐ
21Substitute a known ªgoodº relay for the PCM main
relay.
Was the malfunction fixed?
ÐVerify repairGo to Step 22
22Repair the open in the ignition feed circuit.
Is the action complete?
ÐVerify repairÐ
23Locate and repair the ground connection for PCM
circuit.
Is the action complete?
ÐVerify repairÐ
24Replace 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

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±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