2002 ISUZU AXIOM check engine

6E±75
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Multiple PCM Information Sensor DTCs Set

 
StepNo Ye s Value(s) Action
8Locate and repair the open circuit in the MAP or EGR or
Vapor Pressure sensor supply circuit.
Is the action complete?
ÐVerify repairÐ
91. Disconnect the MAP, Vapor pressure sensor and
EGR connector.
2. Ignition ªONº.
3. Measure the resistance of the blow areas:

MAP sensor GND circuit.

EGR GND circuit.

Vapor pressure sensor GND circuit.
Does the voltage resistance near the specified value?
ÐGo to Step 11Go to Step 10
10Locate and repair the short circuit in the MAP or EGR or
Vapor Pressure sensor signal or GND circuit.
Is the action complete?
ÐVerify repairÐ
11 Measure the resistance of the blow areas:

Between CKP Sensor supply circuit and PCM
harness connector. (5Volt supply circuit)
Does the voltage resistance near the specified value?
ÐGo to Step 13Go to Step 12
12Locate and repair the open circuit in the CKP or CMP
sensor supply circuit.
Is the action complete?
ÐVerify repairÐ
131. Disconnect the CKP sensor connector.
2. Ignition ªONº.
3. Measure the voltage of the blow areas:

CKP sensor GND circuit and shield circuit.
Does the voltage resistance near the specified value?
ÐGo to Step 15Go to Step 14
14Locate and repair the short circuit in the CKP sensor
signal or GND circuit.
Is the action complete?
ÐVerify repairÐ
15Are more of the following items for DTCs stored? EGR,
Vapor Pressure Sensor, MAP, CKP, TPS, APS
Ð
Go to
applicable
DTC table
Go to Step 16
16Replace the PCM.
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?
Ð
Go to OBD
System
Check
Ð

6E±76
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Exhaust Gas Recirculation (EGR)
Diagnosis
An EGR flow check diagnosis of the linear EGR system is
covered by DTC P0401. Pintle position error diagnosis is
covered by DTC P0402, P0404, P1404, P0405, P0406. If
EGR diagnostic trouble codes P0401 and/or P0402,
P0404, P1404, P0405, P0406 are encountered, refer to
the DTC charts.
Engine Tech 2 Data Definitions and
Ranges
A/C CLUTCH ± Tech 2 Displays ON or OFF ±
Indicates whether the PCM has commanded the A/C
clutch ON. Used in A/C system diagnostic.
A/C REQUEST Ð Tech 2 Displays YES or NO Ð
Indicates the state of the A/C request input circuit from the
HVAC controls. The PCM uses the A/C request signal to
determine whether A/C compressor operation is being
requested.
AIR/FUEL RATIO Ð Tech 2 Range 0.0-25.5 Ð
Air/fuel ratio indicates the PCM commanded value. In
closed loop, the air/fuel ratio should normally be
displayed around ª14.2-14.7º. A lower air/fuel ratio
indicates a richer commanded mixture, which may be
seen during power enrichment or TWC protection modes.
A higher air/fuel ratio indicates a leaner commanded
mixture. This can be seen during deceleration fuel mode.
AP1 ÐTech 2 Range 0%-100% Ð
AP (accelerator pedal) angle is computed by the PCM
from the AP sensor voltage. AP angle should display
ª13%º at idle and ª85-89%º at wide open throttle.
AP2 ÐTech 2 Range 0%-100% Ð
AP (accelerator pedal) angle is computed by the PCM
from the AP sensor voltage. AP angle should display
ª85-89%º at idle and ª11-15%º at wide open throttle.
AP3 ÐTech 2 Range 0%-100% Ð
AP (accelerator pedal) angle is computed by the PCM
from the AP sensor voltage. AP angle should display
ª85-89%º at idle and ª32-36%º at wide open throttle.
BAROMETRIC PRESSURE Ð Tech 2 Range 10-105
kPa/0.00-5.00 Volts Ð
The barometric pressure reading is determined from the
MAP sensor signal monitored during key up and wide
open throttle (WOT) conditions. The barometric pressure
is used to compensate for altitude differences and is
normally displayed around ª61-104º depending on
altitude and barometric pressure.
CHECK TRANS LAMP Ð AUTO TRANSMISSION Ð
Indicates the need to check for a DTC with the Tech 2
when the lamp is flashing 0.2 seconds ON and 0.2
seconds OFF.
DESIRED EGR POS. Ð Tech 2 Range 0%-100% Ð
Represents the EGR pintle position that the PCM is
commanding.
DESIRED IDLE Ð Tech 2 Range 0-3187 RPM Ð
The idle speed that the PCM is commanding. The PCM
will compensate for various engine loads based on engine
coolant temperature, to keep the engine at the desired
speed.ECT Ð (Engine Coolant Temperature) Tech 2
Range ±40
C to 151
C (±40
F to 304
F) Ð
The engine coolant temperature (ECT) is mounted in the
coolant stream and sends engine temperature
information to the PCM. The PCM applies 5 volts to the
ECT sensor circuit. The sensor is a thermistor which
changes internal resistance as temperature changes.
When the sensor is cold (high resistance), the PCM
monitors a high signal voltage and interprets that as a cold
engine. As the sensor warms (decreasing resistance),
the voltage signal will decrease and the PCM will interpret
the lower voltage as a warm engine.
EGR DUTY CYCLE Ð Tech 2 Range 0%-100% Ð
Represents the EGR valve driver PWM signal from the
PCM. A duty cycle of 0% indicates that no EGR flow is
being commanded; a 100% duty cycle indicates
maximum EGR flow commanded.
EGR FEEDBACK Ð Tech 2 Range 0.00-5.00 Volts Ð
Indicates the EGR pintle position sensor signal voltage
being monitored by the PCM. A low voltage indicates a
fully extended pintle (closed valve); a voltage near 5 volts
indicates a retracted pintle (open valve).
ENGINE LOAD Ð Tech 2 Range 0%-100% Ð
Engine load is calculated by the PCM from engine speed
and MAF sensor readings. Engine load should increase
with an increase in RPM or air flow.
ENGINE RUN TIME Ð Tech 2 Range
00:00:00-99:99:99 Hrs:Min:Sec Ð
Indicates the time elapsed since the engine was started.
If the engine is stopped, engine run time will be reset to
00:00:00.
ENGINE SPEED Ð Range 0-9999 RPM Ð
Engine speed is computed by the PCM from the 58X
reference input. It should remain close to desired idle
under various engine loads with engine idling.
EVAP PURGE PWM Ð Tech 2 Range 0%-100% Ð
Represents the PCM commanded PWM duty cycle of the
EVAP purge solenoid valve. ª0%º displayed indicates no
purge; ª100%º displayed indicates full purge.
FUEL PUMP Ð Tech 2 Displays ON or OFF Ð
Indicates the PCM commanded state of the fuel pump
relay driver circuit.
HO2S BANK 1, SEN. 1
Ð Tech 2 Range 0-1132 mV Ð
Represents the fuel control exhaust oxygen sensor
output voltage. Should fluctuate constantly within a range
between 10 mV (lean exhaust) and 1000 mV (rich
exhaust) while operating in closed loop.
HO2S BANK 1, SEN. 2
Ð Tech 2 Range 0-1000mV Ð
Monitors the exhaust oxygen sensor output voltage. The
PCM monitors the operating efficiency of catalytic
converter by comparing the output voltages of sensor 1
and sensor 2 in this bank. If the catalytic converter is
operating efficiently, the output voltage of sensor 1 will
give a greater fluctuation than that of sensor 2. If the
PCM detects an abnormal level of voltage fluctuation
from sensor 2, a DTC P0420 will be set, indicating that the
catalytic converter for this bank is no longer operating
efficiently.

6E±78
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
MISFIRE CUR. CYL. #1 /#2 /#3 /#4 / #5 / #6 Ð Tech 2
Range 0-65535 Counts Ð
The misfire history counters display the relative level of
misfire that has been detected on each cylinder. The
misfire history counters will not update or show any
activity until a misfire DTC (P0300) has become active.
MISFIRE FAILURES SINCE FIRST FAIL Ð Tech 2
Range 0-65535 Counts Ð
Indicates the number of 200 crankshaft revolution sample
periods during which the level of misfire was sufficiently
high to report a fail.
MISFIRE PASSES SINCE FIRST FAIL Ð Tech 2
Range 0-65535 Counts Ð
Indicates the number of 200 crankshaft revolution sample
periods during which the level of misfire was sufficiently
low to report a pass.
POWER ENRICHMENT Ð Tech 2 Displays ACTIVE
or INACTIVE Ð
ªACTIVEº displayed indicates that the PCM has detected
conditions appropriate to operate in power enrichment
mode. The PCM will command power enrichment mode
when a large increase in throttle position and load is
detected. While in power enrichment mode, the PCM will
increase the amount of fuel delivered by entering open
loop and increasing the injector pulse width. This is done
to prevent a possible sag or hesitation from occurring
during acceleration.
SPARK Ð Tech 2 Range ±64
to 64
Ð
Displays the amount of spark advance being commanded
by the PCM on the IC circuit.
START-UP ECT Ð Tech 2 Range ±40
C to 151
C
(±40
F to 304
F) Ð
Indicates the engine coolant temperature at the time that
the vehicle was started. Used by the HO2S diagnostic to
determine if the last start-up was a cold start.
START-UP IAT Ð Tech 2 Range ±40
C to 151
C
(±40
F to 304
F) Ð
Indicates the intake air temperature at the time that the
vehicle was started. Used by the HO2S diagnostic to
determine if the last start-up was a cold start.
TOTAL MISFIRE CURRENT COUNT Ð Tech 2
Range 0-255 Ð
Indicates the total number of cylinder firing events that
were detected as being misfires during the last 200
crankshaft revolution sample period.
TP Ð Tech 2 Range 0%-100% Ð
TP (throttle position) angle is computed by the PCM from
the TP sensor voltage. TP angle should display ª3-5%º
at idle and ª100%º at wide open throttle.
CATALYST PROTECTION MODE Ð Tech 2 Displays
YES or NO Ð
ªYESº displayed indicates that the PCM has detected
conditions appropriate to operate in TWC protection
mode. The PCM will decrease the air/fuel ratio to a value
that depends on mass air flow (higher mass air flow =
lower air/fuel ratio).UPSHIFT LAMP (MANUAL TRANSMISSION)
VEHICLE SPEED Ð Tech 2 Range 0-255 km/h
(0-155 mph) Ð
The vehicle speed sensor signal is converted into km/h
and mph for display.
WEAK CYLINDER Ð Tech 2 Displays Cylinder
Number Ð
This indicates that the PCM has detected crankshaft
speed variations that indicate 2% or more cylinder firing
events are misfires.
Typical Scan Data Values
Use the Typical Scan Data Values Table only after the
On-Board Diagnostic System Check has been
completed, no DTC(s) were noted, and you have
determined that the on-board diagnostics are functioning
properly. Tech 2 values from a properly-running engine
may be used for comparison with the engine you are
diagnosing. The typical scan data values represent
values that would be seen on a normally-running engine.
NOTE: A Tech 2 that displays faulty data should not be
used, and the problem should be reported to the Tech 2
manufacturer. Use of a faulty Tech 2 can result in
misdiagnosis and unnecessary replacement of parts.
Only the parameters listed below are referred to in this
service manual for use in diagnosis. For further
information on using the Tech 2 to diagnose the PCM and
related sensors, refer to the applicable reference section
listed below. If all values are within the typical range
described below, refer to the
Symptoms section for
diagnosis.
Test Conditions
Engine running, lower radiator hose hot, transmission in
park or neutral, closed loop, accessories off, brake not
applied and air conditioning off.

6E±79
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
3.5L V-6 Engine (Automatic and Manual Transmission)
Tech 2
Parameter
Data ListUnits DisplayedTypical Data
Values (IDLE)Typical Data
Values
(2500 RPM)Refer To
A/C Clutch
RelayEngineOn/OffOffOffGeneral Description and
Operation, A/C Clutch
Circuit Operation
A/C RequestEngineYes/NoNoNoGeneral Description and
Operation, A/C Request
Signal
Air/Fuel RatioEngineRatio: _ to 114.714.7General Description and
Operation, Fuel System
Metering Purpose
APP Sensor1EnginePercent11±1335±40General Description and
Operation
APP Sensor2EnginePercent87±8860±65General Description and
Operation
APP Sensor3EnginePercent87±8850±57General Description and
Operation
Barometric
PressureEnginekPa61-104
(depends on
altitude and
barometric
pressure)61-104
(depends on
altitude and
barometric
pressure)General Description and
Operation
Brake Light
SwitchEngineOpen 0V/Closed
12VOpen 0VOpen 0VRefer to Section 5
Check Trans
Lamp (Auto
Trans)EngineOn/OffOffOff4L30-E Automatic
Transmission Diagnosis
Cruise Main
SwitchEngineActive/InactiveInactiveInactiveRefer to Section 10
Cruise Set
SwitchEngineActive/InactiveInactiveInactiveRefer to Section 10
Cruise Cancel
SwitchEngineActive/InactiveInactiveInactiveRefer to Section 10
Cruise
Resume
SwitchEngineActive/InactiveInactiveInactiveRefer to Section 10
Decel Fuel
CutoffEngineActive/InactiveInactiveInactiveGeneral Description and
Operation, Deceleration
Mode
Desired EGR
PositionEnginePercent0%0%General Description and
Operation, EGR Pintle
Position Sensor
Desired Idle
SpeedEngineRPM750800General Description and
Operation
ECT (Engine
Coolant Temp)EngineDegrees C,
Degrees F80-100
C
(176-212
F)80-100
C
(176-212
F)General Description and
Operation, Engine
Coolant Temperature
(ECT) Sensor
EGR Closed
Pintle PositionEngineSteps20-4020-40General Description and
Operation, EGR Pintle
Position Sensor

6E±80
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Tech 2
ParameterRefer To Typical Data
Values
(2500 RPM) Typical Data
Values (IDLE) Units Displayed Data List
EGR Duty
CycleEnginePercent0%0%General Description and
Operation, Linear EGR
Operation and Results of
Incorrect Operation
EGR
FeedbackEngineVolts0.45-0.800.45-0.80Ð
EGR
NormalizedEnginePercent0%0%Ð
Engine LoadEnginePercent2.0% - 5.5%8.0% - 16.0%General Description and
Operation, Mass Air Flow
(MAF) Sensor
Time From
StartEngineSecVaries. Resets
at each engine
start.Varies. Resets
at each engine
start.
Ð
Engine SpeedEngineRPMWithin ±50 to
+100 of
ªDesired IdleºActual engine
speed
Ð
EVAP Purge
SolenoidEnginePercent0%0%Diagnosis, EVAP
Emission Canister Purge
Valve Check
EVAP Vent
ValveEngineOn/OffOffOffDiagnosis, EVAP Canister
Purge Solenoid and
EVAP Vacuum Switch
and Visual Check; DTCs:
P1441, P1442
Fuel System
StatusEngineOpen
Loop/Closed
LoopClosed LoopClosed LoopGeneral Description
Fuel LevelEnginePercentÐÐEngine Fuel
Fuel Level
SensorEngineVoltsÐÐEngine Fuel
Fuel Tank
(Vapor)EngineVolts1.02 ± 1.861.02 ± 2.57General Description and
Operation
Pressure
Sensorin. H2OÐÐ
Fuel PumpEngineOn/OffOnOnEngine Fuel
HO2S Bank 1
Sen.1
(millivolts)O2
Sensor
DataMillivolts50-950
changing
quickly50-950, always
changing
quicklyGeneral Description and
Operation, Fuel control
HO2S
HO2S Bank 1
Sen.2
(millivolts)
(Auto Trans)O2
Sensor
DataMillivolts200-700
changing slowly250-650
changing slowlyGeneral Description and
Operation, Fuel Metering
System
HO2S Bank 1
Sen.2
(millivolts)
(Manual
Trans)O2
Sensor
DataMillivolts50-950
changing
quickly50-950
changing
quicklyGeneral Description and
Operation, Fuel Metering
System
HO2S Bank 1
Sen.3
(millivolts)
(Manual
Trans)O2
Sensor
DataMillivolts200-700
changing slowly250-650
changing slowlyGeneral Description and
Operation, Catalyst
Monitor Heated Oxygen
Sensor (Manual Trans)

6E±82
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Tech 2
ParameterRefer To Typical Data
Values
(2500 RPM) Typical Data
Values (IDLE) Units Displayed Data List
Long Term FT
Bank 2 (Long
Term Fuel
Trim)MisfireCounts and
Percentage100 to 150
counts, ±22%
to +17%100 to 150
counts, ±22%
to +17%Diagnosis, Fuel Trim
System Monitor; DTCs:
P0171
MAF (Mass Air
Flow)EngineGrams per
second2.85-6.659.5-16.5General Description and
Operation, MAF; DTCs:
P101, P0102, P0103
MAP kPa
(Manifold
Absolute
EngineKilopascals23-4019-32General Description and
Operation, Manifold
Absolute Pressure (MAP)Absolute
Pressure)Volts0.65-1.320.46-1.10Absolute Pressure (MAP)
Sensor; DTCs: P0106,
P0107, P0108
MILEngineOn/OffOffOffOn-Board Diagnostic
System Check
Misfire Cur. Cyl
#1MisfireCounts0-20-2DTC P0300
Misfire Cur. Cyl
#2MisfireCounts0-20-2DTC P0300
Misfire Cur. Cyl
#3MisfireCounts0-20-2DTC P0300
Misfire Cur. Cyl
#4MisfireCounts0-20-2DTC P0300
Misfire Cur. Cyl
#5MisfireCounts0-20-2DTC P0300
Misfire Cur. Cyl
#6MisfireCounts0-20-2DTC P0300
Misfire Hist.
Cyl #1MisfireCounts00DTC P0300
Misfire Hist.
Cyl #2MisfireCounts00DTC P0300
Misfire Hist.
Cyl #3MisfireCounts00DTC P0300
Misfire Hist.
Cyl #4MisfireCounts00DTC P0300
Misfire Hist.
Cyl #5MisfireCounts00DTC P0300
Misfire Hist.
Cyl #6MisfireCounts00DTC P0300
Misfire Failures
Since First FailMisfireCounts00DTC P0300
Misfire Passes
Since First FailMisfireCounts00DTC P0300
PNP
(Park/Neutral
Position)EngineP-N /
R-D-3-2-LP-NP-N4L30-E Automatic
Transmission Diagnosis
Power
EnrichmentEngineNO/YESNONOGeneral Description and
Operation, Acceleration
Mode
PSP Switch
(Power
Steering
Pressure)EngineNormal/HiNormal
PressureNormal
PressureRefer to 2A Section

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