2002 ISUZU AXIOM ignition

6E±61
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
On-Board Diagnostic (OBD II) System Check

StepActionValue(s)Ye sNo
11. Ignition ªONº, engine ªOFFº.
2. Observe the malfunction indicator lamp (MIL or
ªCheck Engine lampº).
Is the MIL (ªCheck Engine lampº)ªONº?
ÐGo to Step 2
Go to No
MIL(ªCheck
Engine lampº)
21. Ignition ªONº, engine ªOFFº.
2. Observe the ªReduced Power lampº.
Is the RPL (ªReduced Power lampº) ªONº?
ÐGo to Step 3
Go to No
RPL(ªReduce
d Power
lampº)
31. Ignition ªOFFº.
2. Install Tech 2.
3. Ignition ªONº.
4. Attempt to display PCM engine data with the
Tech 2.
Does the Tech 2 display PCM data?
ÐGo to Step 4Go to Step 12
41. Using the Tech 2 output tests function, select MIL
(ªCheck Engine lampº) control and command the
MIL (ªCheck Engine Lampº) ªOFFº.
2. Observe the MIL (ªCheck Engine lampº).
Did the MIL (ªCheck Engine lampº) turn ªOFFº?
ÐGo to Step 5
Go to
MIL(ªCheck
Engine lampº)
On Steady
51. Using the Tech 2 output tests function, select MIL
(ªCheck Engine lampº) control and command the
RPL (ªReduced Power lampº) ªOFFº.
2. Observe the RPL (ªReduced Power lampº).
Did the MIL (ªReduced Power lampº) turn ªOFFº?
ÐGo to Step 6
Go to
RPL(ªReduce
d Power
lampº) On
Steady
6Select ªDisplay DTCsº with the Tech 2.
Are any DTCs stored?
ÐGo to Step 7Go to Step 11
7Stored DTCs.
P0562, P0563, P0601, P0602, P0604, P0606, P1625,
P1635, P1639, P1640, P1650
Are the applicable DTCs stored?
Ð
Go to
applicable
DTC table
Go to Step 8
8Stored DTCs.
P1514, P1515, P1516, P1523, P1125, P1290, P1295,
P1299
Are the applicable DTCs stored?
Ð
Go to
applicable
DTC table
Go to Step 9
9Stored DTCs.
1. P0425, P0106, P0107, P1107, P0401, P1404,
P0405, P1120, P1221, P1515, P1516, P1275,
P1635, P1271, P1273, P1285, P1272
2. P0336, P0337, P1220, P1515, P1221, P1516,
P1280, P1639, P1271, P1272
Are the applicable DTCs stored?
Ð
Go to
ªMultiple
PCM
Information
sensor DTCs
Setº
Go to Step 10
10Attempt to crank the starter motor
Did the starter motor crank?
ÐGo to Step 10
Go to Starter
control
system
11Attempt to start the engine.
Did the engine start and continue to run?
ÐGo to Step 6
Go to Cranks
But Will Not
Run

6E±62
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
On-Board Diagnostic (OBD II) System Check

 
StepNo Ye s Value(s) Action
12Compare PCM data values displayed on the Tech 2 to
the typical engine scan data values.
Are the displayed values normal or close to the typical
values?
Ð
Go to
Symptom
Refer to
indicated
Component
System
Checks
131. Ignition ªOFFº, disconnect the PCM.
2. Ignition ªONº, engine ªOFFº.
3. Check the Class 2 data circuit for an open, short to
ground, or short to voltage. Also, check the DLC
ignition feed circuit for an open or short to ground
and the DLC ground circuit for an open.
4. If a problem is found, repair as necessary.
Was a problem found?
ÐGo to Step 2Go to Step 14
141. Attempt to reprogram the PCM. Refer to Powertrain
Control Module (PCM) in On-Vehicle Service.
2. Attempt to display PCM data with the Tech 2.
Does the Tech 2 display PCM engine data?
ÐGo to Step 2Go to Step 15
15Replace 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?
ÐGo to Step 2Ð

6E±63
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
A/C Clutch Control Circuit Diagnosis
060R100063
Circuit Description
When air conditioning and blower fan are selected, and if
the system has a sufficient refrigerant charge, a 12-volt
signal is supplied to the A/C request input of the
powertrain control module (PCM). The A/C request
signal may be temporarily canceled during system
operation by the electronic thermostat in the evaporator
case. When the A/C request signal is received by the
PCM, the PCM supplies a ground from the compressor
clutch relay if the engine operating conditions are within
acceptable ranges. With the A/C compressor relay
energized, voltage is supplied to the compressor clutch
coil.
The PCM will enable the compressor clutch to engage
whenever A/C has been selected with the engine running,
unless any of the following conditions are present:

The throttle is greater than 90%.

The ignition voltage is below 10.5 volts.

The engine speed is greater than 4500 RPM for 5
seconds or 5400 RPM.
The engine coolant temperature (ECT) is greater
than 125
C (257
F).

The intake air temperature (IAT) is less than 5
C
(41
F).

The power steering pressure switch signals a high
pressure condition.
Diagnostic Aids
To diagnose an the intermittent fault, check for following
conditions:

Poor connection at the PCM±Inspect connections 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. If the harness appears to OK, observe the
A/C clutch while moving connectors and wiring
harnesses related to the A/C. A sudden clutch
malfunction will indicate the source of the intermittent
fault.

6E±65
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
A/C Clutch Control Circuit Diagnosis

 
StepNo Ye s Value(s) Action
7Temporarily substitute the A/C compressor relay in
place of the A/C thermostat relay, then repeat Step 5.
Did the ªA/C Requestº display indicate ªYesº?
ÐGo to Step 8Go to Step 9
8Replace the original A/C thermostat relay.
Is the action complete?
ÐVerify repairÐ
9Does the blower operate?ÐGo to Step 10Go to Step 11
10Repair the blower.
Is the action complete?
ÐVerify repairÐ
11Check for a faulty 10A A/C fuse in the underdash fuse
panel.
Was the 10A fuse OK?
ÐGo to Step 13Go to Step 12
12Check for short circuit and make repairs if necessary.
Replace the 10A A/C fuse.
Is the action complete?
ÐVerify repairÐ
131. Remove the glove box to gain access to the A/C
thermostat.
2. Disconnect the thermostat connector.
3. Attach a fused jumper between ground and the
thermostat wire.
4. A/C ªONº.
5. Blower ªONº.
Dose A/C request indicate ªYESº on the Tech 2?
ÐGo to Step 14Go to Step 17
141. Ignition ªONº.
2. Use a DVM to check voltage at the electronic A/C
thermostat.
Was voltage equal to the specified value?
B+Go to Step 17Go to Step 15
15Check for open wire between the thermostat and the
A/C switch.
Was the wire open?
ÐGo to Step 16Go to Step 17
16Repair the open wire between the thermostat and the
A/C switch.
Is the action complete?
ÐVerify repairÐ
17Check for an open circuit between A/C thermostat relay
and PCM A/C request terminal (F45).
Was there an open circuit?
ÐGo to Step 18Go to Step 19
18Repair the open circuit between the PCM and A/C
thermostat relay.
Is the action complete?
ÐVerify repairÐ
191. Ignition ªONº.
2. Use a DVM to check voltage at the A/C pressure
switch.
Was voltage equal to the specified value?
B+Go to Step 21Go to Step 20
20Repair the open circuit between the 10A A/C fuse and
the pressure switch.
Is the action complete?
ÐVerify repairÐ

6E±66
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
A/C Clutch Control Circuit Diagnosis

 
StepNo Ye s Value(s) Action
21Use an ohmmeter to check continuity between the
pressure switch and the A/C thermostat relay.
Was the circuit open?
ÐGo to Step 22Go to Step 23
22Repair the open circuit between the pressure switch
and the A/C thermostat relay.
Is the action complete?
ÐVerify repairÐ
23Check for damaged pin or terminal at F45 of the PCM.
Was a damaged pin or terminal found?
ÐGo to Step 24Go to Step 25
24Repair the damaged pin or terminal.
Is the action complete?
ÐVerify repairÐ
25Replace the PCM.
IMPORTANT:The replacement PCM must be
programmed. Refer to
On-Vehicle Service in
Powertrain Control Module 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
261. Remove the A/C compressor relay.
2. Ignition ªONº.
3. Use a DVM to check voltage at both of the wires at
the A/C compressor relay socket.
Is the voltage equal to the specified value?
B+Go to Step 28Go to Step 27
27Repair the faulty wire between the A/C fuse and the
A/C compressor relay .
Is the action complete?
ÐVerify repairÐ
281. A/C compressor relay removed.
2. Engine idling.
3. A/C ªONº.
4. Blower ªONº.
5. Use a DVM to measure voltage between the wire at
the A/C compressor relay socket and battery+.
Did the DVM indicate the specified value?
B+Go to Step 32Go to Step 29
29Check for an open wire between PCM terminal F4 and
the A/C compressor relay.
Was the wire open?
ÐGo to Step 30Go to Step 31
30Repair the open wire between the PCM and the A/C
compressor relay.
Is the action complete?
ÐVerify repairÐ
31Check for a damaged pin or terminal at F4 of the PCM.
Was a damaged pin or a terminal found?
ÐGo to Step 24Go to Step 25

6E±68
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Electronic Ignition System Diagnosis
If the engine cranks but will not run or immediately stalls,
the Engine Cranks But Will Not Start chart must be used
to determine if the failure is in the ignition system or the
fuel system. If DTC P0300 through P0306, P0341, or
P0336 is set, the appropriate diagnostic trouble code
chart must be used for diagnosis.
If a misfire is being experienced with no DTC set, refer to
the
Symptoms section for diagnosis.
EVAP Canister Purge Solenoid and
EVAP Vent Solenoid Valve
A continuous purge condition with no purge commanded
by the PCM will set a DTC P1441. Refer to the DTC charts
for further information.
Visual Check of The Evaporative
Emission Canister

If the canister is cracked or damaged, replace the
canister.

If fuel is leaking from the canister, replace the canister
and check hoses and hose routing.
Fuel Metering System Check
Some failures of the fuel metering system will result in an
ªEngine Cranks But Will Not Runº symptom. If this
condition exists, refer to the
Cranks But Will Not Run
chart. This chart will determine if the problem is caused
by the ignition system, the PCM, or the fuel pump
electrical circuit.
Refer to
Fuel System Electrical Test for the fuel system
wiring schematic.
If there is a fuel delivery problem, refer to
Fuel System
Diagnosis
, which diagnoses the fuel injectors, the fuel
pressure regulator, and the fuel pump. If a malfunction
occurs in the fuel metering system, it usually results in
either a rich HO2S signal or a lean HO2S signal. This
condition is indicated by the HO2S voltage, which causes
the PCM to change the fuel calculation (fuel injector pulse
width) based on the HO2S reading. Changes made to the
fuel calculation will be indicated by a change in the long
term fuel trim values which can be monitored with a
Tech 2. Ideal long term fuel trim values are around 0%;
for a lean HO2S signal, the PCM will add fuel, resulting in
a fuel trim value above 0%. Some variations in fuel trim
values are normal because all engines are not exactly the
same. If the evaporative emission canister purge is ªONº,
the fuel trim may be as low as ±38%. If the fuel trim values
are greater than +23%, refer to
DTC P0131, DTC P0151,
DTC P0171, and DTC 1171
for items which can cause a
lean HO2S signal.
Fuel System Pressure Test
A fuel system pressure test is part of several of the
diagnostic charts and symptom checks. To perform this
test, refer to
Fuel Systems Diagnosis.
Fuel Injector Coil Test Procedure and
Fuel Injector Balance Test Procedure
T32003
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart:
2. Relieve the fuel pressure by connecting the J
34730-1 Fuel Pressure Gauge to the fuel pressure
connection on the fuel rail.
CAUTION: 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.
Place the fuel pressure gauge bleed hose in an
approved gasoline container.
With the ignition switch ªOFFº, open the valve on the
fuel pressure gauge.
3. Record the lowest voltage displayed by the DVM
after the first second of the test. (During the first
second, voltage displayed by the DVM may be
inaccurate due to the initial current surge.)
Injector Specifications:
Resistance (Ohms)
Voltage Specification at
10
C-35
C (50
F-95
F)
11.8 ± 12.65.7 ± 6.6

The voltage displayed by the DVM should be within
the specified range.

The voltage displayed by the DVM may increase
throughout the test as the fuel injector windings
warm and the resistance of the fuel injector windings
changes.

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±74
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

P1275, P1639, P1271, P1273

P1285, P1272, P1273

P0336, P0337

P1220, P1515, P1221, P1515, P1516

P1280, P1271, P1272
Check for the following conditions:

Poor connection at PCM. Inspect the harness
connectors for backed±out terminals, improper
mating, broken locks, improperly formed or damage
terminals, and a poor terminal±to±wire connection.
Damaged harness. Inspect the wiring harness for
damage. If the harness is not damaged, observe an
affected sensor fs displayed value on the Tech 2 with
the ignition ªONº and the engine ªOFFº while you
move the connectors and the wiring harnesses
related to the following sensors:

Vapor Pressure (Fuel Tank Pressure) Sensor

MAP Sensor

EGR

TPS1/TPS2

APS1/APS2/APS3

CKP
Multiple PCM Information Sensor DTCs Set

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Turn the ignition ªOFFº, disconnect the PCM.
2. Turn the ignition ªONº, check the 5 volt reference 1
and 2 circuit for the following conditions:

A poor connection at the PCM.

An open between the PCM connector and the
splice.

A short to ground.

A short to voltage.
Is there an open or short?
ÐGo to Step 3Go to Step 4
3Repair the open or short.
Is the action complete?
ÐVerify repairÐ
4Check the sensor ground circuit for the following
conditions:

A poor connection at the PCM or the affected
sensors.

An open between the PCM connector and the
affected sensors.
Is there an open or a poor connection?
ÐGo to Step 5Go to Step 6
5Repair the open or the poor connection.
Is the action complete?
ÐVerify repairÐ
6Following below the DTCs stored:
P1635, P1639
Ð
Go to
applicable
DTC table
Go to Step 7
7 Measure the resistance below the items:

Between EGR sensor supply circuit and Vapor
Pressure Sensor supply circuit.

Between MAP sensor supply circuit and Vapor
Pressure Sensor supply circuit.

Between Vapor Pressure Sensor supply circuit
and PCM harness connector. (5Volt supply
circuit)
Is the resistance near the specified value?
ÐGo to Step 9Go to Step 8