2002 ISUZU AXIOM OBD port

6E±445
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1280 - APS 2 Circuit Fault

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Was the ªElectric Throttle Control (ETC) System
Checkº performed?
ÐGo to Step 3
Go to ETC
System
Check
3Observe the AP angle reading on the Tech 2 while
slowly opening the throttle.
Does the AP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?Idle position
=86 ~ 88
%Wide open
throttle =12
~ 14 %
Refer to
Diagnostic
Aids
Go to Step 4
41. Disconnect the AP sensor.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
0VGo to Step 5Go to Step 6
51. Connect a test light between the 5 voltage supply
circuit and the AP2 sensor signal circuit at the AP
sensor harness connector.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
5VGo to Step 8Go to Step 7
6Check the following items;
1. AP2 signal circuit for a short to volt.
2. AP2 sensor ground circuit for high resistance
between the PCM and the AP sensor.
3. AP2 sensor ground circuit for a poor connection.
4. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 9
7Check the following items;
1. AP2 signal circuit or 5 volt supply circuit for a poor
connection.
2. AP2 signal circuit or 5 volt supply circuit for high
resistance between the PCM and the AP2 sensor.
3. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 9
8Replace the AP sensor.
Is the action complete?
ÐVerify repairÐ
9Replace 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±447
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1285 ± APS 3 Circuit Fault

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
2Was the ªElectric Throttle Control (ETC) System
Checkº performed?
ÐGo to Step 3
Go to ETC
System
Check
3Observe the AP angle reading on the Tech 2 while
slowly opening the throttle.
Does the AP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?Idle position
=86 ~ 88
%Wide open
throttle =32
~ 36 %
Refer to
Diagnostic
Aids
Go to Step 4
41. Disconnect the AP sensor.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
0VGo to Step 5Go to Step 6
51. Connect a test light between the 5 volt supply circuit
and the AP3 sensor signal circuit at the AP sensor
harness connector.
2. Observe the AP sensor reading on the Tech 2.
Is the AP sensor reading near the specified value?
5VGo to Step 8Go to Step 7
6Check the following items;
1. AP3 signal circuit for a short to voltage.
2. AP3 sensor ground circuit for high resistance
between the PCM and the AP sensor.
3. AP3 sensor ground circuit for a poor connection.
4. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 9
7Check the following items;
1. AP3 signal circuit or 5 volt supply circuit for a poor
connection.
2. AP3 signal circuit or 5 voltage supply circuit for high
resistance between the PCM and the AP3 sensor.
3. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
ÐVerify repairGo to Step 9
8Replace the AP sensor.
Is the action complete?
ÐVerify repairÐ
9Replace 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±478
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
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.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.3. Determines if the PCM is able to control the EVAP
purge solenoid valve.
4. Determines if the DTC will set under the conditions
present when the DTC was originally stored. If not,
the fault is intermittent.
5. Checks for a grounded EVAP purge solenoid driver
circuit, a faulty EVAP vacuum switch, or a leaking
EVAP purge solenoid valve.
DTC P1441 ± EVAP System Flow During Non-Purge

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªOFFº.
2. Remove the fuel filler cap.
3. Ignition ªONº.
4. Observe ªFuel Tank Pressureº on the Tech 2.
Is ªFuel Tank Pressureº at the specified value?
1.51VGo to Step 3
Go to DTC
P0452 or
P0453
31. Re-install the fuel filler cap.
2. Using the Tech 2, command the EVAP Vent
Solenoid Valve ªONº (Closed).
3. Disconnect the canister side rubber hose end that
hose is connected between the Purge Solenoid
Valve and Canister.
IMPORTANT:Before continuing with the diagnosis,
zero the EVAP pressure/purge cart J41413 (refer to the
tool operating instructions).
And them monitor the fuel tank inner pressure using the
Tech 2.
Does the fuel tank pressure remain the specified
value?
1.52 - 1.60VGo to Step 4Go to Step 6
41. Disconnect the EVAP pressure/purge cart J41413,
and then plug the hose end.
2. Disconnect the rubber hose end of engine vacuum
source side, (the hose connected between Purge
Solenoid Valve and engine).
3. Connect the vacuum hand pump to this rubber hose
end.
4. Then apply the -15 in H2O vacuum by the vacuum
pump.
5. Monitor the fuel tank inner pressure using the Tech
2.
Does the fuel tank inner pressure hold the specified
value?
1.47 - 1.51VGo to Step 6Go to Step 5
5Replace the Purge Solenoid Valve.
ÐVerify RepairÐ

6E±494
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1571 Brake Switch No Operation

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªOffº.
Engine ªOffº.
2. Check following fuses.

BACK 15A

STOP LAMP 15A
Was a problem found?
ÐVerify repairGo to Step 3
31. Make adjustment to the brake switch.
(Refer to
ªBrake switchº in ª10A CRUISE
CONTROL SYSTEMº.
)
Was the problem found?
ÐVerify repairGo to Step 4
41. Push the shaft on brake switch.
2. Check shaft operation for smooth movement.
Was the problem found?
ÐVerify repairÐ
51. Disconnect the connector at brake switch.
2. Check following terminal pin by ohmmeter.
(Leave the shaft position at brake switch. Don't
push it.)

Between pin 1 and pin 2

Between pin 3 and pin 4
Was it specified value?
Between pin1
and pin2 is
0
, Between
pin3 and pin4
is 8

Go to Step 6Go to Step 9
61. Disconnect the connector at brake switch.
2. Check following terminal pin at ohmmeter.
(Don't press the button of the brake switch.)

wBetween pin 1 and pin 2

wBetween pin 3 and pin 4
Was it specified value?
Between pin1
and pin2 is
8
, Between
pin3 and pin4
is 0

Go to Step 7Go to Step 9
71. Probe related circuits for open or short to ground.
2. If a problem was found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 8
81. Replace 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.
Was the action completed?
ÐVerify repairÐ
91. Replace the brake switch.
Was the action completed?
ÐVerify repairÐ

6E±497
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1635 Reference Voltage # 1 Circuit Fault


StepActionValue(s)Ye sNo
1Was the ªOn-Board(OBD)System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªONº, engine not running.
2. Using a DVM at the PCM side of the connector,
check the voltage at terminal S38 (RED) pin.
Is the voltage in specified range?
4.95 ± 5.0V
Go to ETC
System
Check
Go to Step 3
31. Ignition ªONº, engine not running.
2. Using a DVM at the PCM side of the connector,
check the voltage at terminal F20 (RED/WHT) pin.
Is the voltage in specified range?
11.6 ± 12.7VGo to Step 4 Go to Step 5
41. Ignition ªONº, engine not running.
2. Using a DVM at the PCM side of the connector,
check the voltage at terminal F57 (RED/WHT) pin.
Is the voltage in specified range?
11.6 ± 12.7VGo to Step 6 Go to Step 5
5Observe the battery voltage and circuit. If a problems
found, repair it as necessary.
Was the problem found?
ÐVerify repairGo to Step 6
6Replace 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±499
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P1639 Reference Voltage # 2 Circuit Fault

StepActionValue(s)Ye sNo
1Was the ªOn-Board (OBD) System Checkº performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Ignition ªONº, engine not running.
2. Using a DVM at the PCM side of the connector,
check the voltage at terminal S36 (BLK) pin.
Is the voltage in specified range?
4.95 ± 5.0V
Go to ETC
System
Check
Go to Step 3
31. Ignition ªONº, engine not running.
2. Using a DVM at the PCM side of the connector,
check the voltage at terminal F20(RED/WHT) pin.
Is the voltage in specified range?
11.6 ± 12.7VGo to Step 4 Go to Step 5
41. Ignition ªONº, engine not running.
2. Using a DVM at the PCM side of the connector,
check the voltage at terminal F57 (RED/WHT) pin.
Is the voltage in specified range?
11.6 ± 12.7VGo to Step 6 Go to Step 5
5Observe the battery voltage and circuit.
If a problem is found, repair it as necessary.
Was the problem found?
ÐVerify repairGo to Step 6
6Replace 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±506
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Symptom Diagnosis
Preliminary Checks
Before using this section, perform the ªOn-Board
Diagnostic (OBD) System Checkº and verify all of the
following items:

The powertrain control module (PCM), and
malfunction indicator lamp (MIL) (Check Engine
lamp) and Reduced Power Lamp (RPL) are operating
correctly.

There are no DTC(s) stored.

Tech 2 data is within normal operating range. Refer to
Typical Scan Data Values.

Verify the customer complaint and locate the correct
symptom in the table of contents. Perform the
procedure included in the symptom chart.
Visual/Physical Check
Several of the symptom procedures call for a careful
visual/physical check. This can lead to correcting a
problem without further checks and can save valuable
time.
This check should include the following items:

PCM grounds for cleanliness, tightness and proper
location.

Vacuum hoses for splits, kinks, and proper
connections, as shown on the ªVehicle Emission
Control Informationº label. Check thoroughly for any
type of leak or restriction.

Air intake ducts for collapsed or damaged areas.

Air leaks at throttle body mounting area, mass air flow
(MAF) sensor and intake manifold sealing surfaces.

Ignition components for cracking, hardness, and
carbon tracking.

Wiring for proper connections, pinches and cuts.
Intermittents
IMPORTANT:An intermittent problem may or may not
turn on the malfunction indicator lamp (MIL) or store a
DTC. DO NOT use the Diagnostic Trouble Code (DTC)
charts for intermittent problems. The fault must be
present to locate the problem.
Most intermittent problems are caused by faulty electrical
connections or wiring. Perform a careful visual/physical
check for the following conditions:

Poor mating of the connector halves or a terminal not
fully seated in the connector (backed out).

Improperly formed or damaged terminal.

All connector terminals in the problem circuit should
be carefully checked for proper contact tension.

Poor terminal-to-wire connection. This requires
removing the terminal from the connector body to
check.
Road test the vehicle with a J 39200 Digital Multimeter
connected to a suspected circuit. An abnormal voltage
when the malfunction occurs is a good indication that
there is a fault in the circuit being monitored.
Use a Tech 2 to help detect intermittent conditions. The
scan tool has several features that can be used to locatean intermittent condition. Use the following feature to find
intermittent faults:

Using a Tech 2's ªFreeze Frameº buffer or ªFailure
Recordsº buffer can aid in locating an intermittent
condition. Review and record the information in the
freeze frame or failure record associated with the
intermittent DTC being diagnosed. The vehicle can
be driven within the conditions that were present
when the DTC originally set.
To check for loss of diagnostic code memory, disconnect
the MAP sensor and idle the engine until the MIL (Check
Engine lamp) comes on. DTC P0107 should be stored
and kept in memory when the ignition is turned ªOFFº. If
not, the PCM is faulty. When this test is completed, make
sure that you clear the DTC P0107 from memory.
An intermittent MIL (Check Engine lamp) with no stored
DTC may be caused by the following:

Ignition coil shorted to ground and arcing.

MIL (Check Engine lamp) wire to PCM shorted to
ground.

Poor PCM grounds. Refer to the PCM wiring
diagrams.
Check for improper installation of electrical options such
as lights, cellular phones, etc. Check all wires from the
PCM to the ignition coils for poor connections.
Check for an open diode across the A/C compressor
clutch and check for other open diodes (refer to wiring
diagrams in
Electrical Diagnosis).
If problem has not been found, refer to
PCM Connector
Symptom
tables.

Check the ªCalibration IDº of the PCM, and compare it
with the latest Isuzu service bulletins and/or Isuzu
EEPROM reprogramming equipment to determine if
an update to the PCM's reprogrammable memory
has been released. To check the ªCalibration IDº,
connect the Tech 2, then look for ªPowertrainº, then
select ªCalibration IDº. This identifies the contents of
the reprogrammable software and calibration
contained in the PCM. If the ªCalibration IDº is not the
most current available, it is advisable to reprogram
the PCM's EEPROM memory, which may either help
identify a hard-to-find problem or may fix the problem.

Calibration ID (example)
Part number 9377709
Broadcast Code CYYD
Identifier 801

6E±507
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Hard Start Symptom

StepActionValue(s)Ye sNo
1DEFINITION:
Engine cranks, but does not start for a long time. Does
eventually run, or may start but immediately stall.
Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Was the ªElectric Throttle Control (ETC) System
Checkº performed?
ÐGo to Step 3
Go to ETC
System
Check
31. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
ÐVerify repairGo to Step 4
4Was a visual/physical check performed?
ÐGo to Step 5
Go to Visual/
Physical
Check
5Check engine coolant temperature (ECT) sensor for
shift in value. After 8 hours with the hood up and the
engine not running, connect the Tech 2. With the
ignition ªONº and the engine not running, compare
engine coolant temperature to intake air temperature.
Are ECT and IAT within the specified value of each
other?
+ 5
C (+ 9
F)Go to Step 10Go to Step 6
61. Using a Tech 2, display the engine coolant
temperature and note the value.
2. Check the resistance of the engine coolant
temperature sensor.
3. Refer to
Engine Coolant Temperature Sensor
Temperature vs. Resistance
chart on DTC P0118
Diagnostic Support
for resistance specifications.
Is the resistance value near the resistance for the
temperature noted?
ÐGo to Step 8Go to Step 7
7Replace the ECT sensor.
Is the action complete?
ÐVerify repairÐ
8Locate and repair high resistance or poor connection in
the ECT signal circuit or the ECT sensor ground.
Is the action complete?
ÐVerify repairÐ
91. Check for a faulty, plugged, or incorrectly installed
PCV valve.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 10
101. Check for water- or alcohol-contaminated fuel.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 11
111. Perform the procedure in Fuel System Pressure
Test
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 12