2002 ISUZU AXIOM catalytic converter

0A±9
GENERAL INFORMATION
Lifting Instructions
CAUTION:

If a lifting device other than the original jack is
used, it is most important that the device be
applied only to the correct lifting points. Raising
the vehicle from any other point may result in
serious damage.
When jacking or lifting a vehicle at the frame side
rail or other prescribed lift points, be certain that
lift pads do not contact the catalytic converter,
brake pipes or cables, or fuel lines. Such contact
may result in damage or unsatisfactory vehicle
performance.
Lifting Points and Supportable Point Locations
C00RX002
Lifting Point: Front

When using a floor jack, lift on the Convex portion of
the skid plate.
545RS001

0A±13
GENERAL INFORMATION
N Ð Newtons
NA Ð Natural Aspirated
NC Ð Normally Closed
N´M Ð Newton Meters
NO Ð Normally Open
NOX Ð Nitrogen, Oxides of
OBD Ð On-Board Diagnostic
OD Ð Outside Diameter
O/D Ð Over Drive
OHC Ð Overhead Camshaft
OL Ð Open Loop
O2 Ð Oxygen
O2S Ð Oxygen Sensor
PAIR Ð Pulsed Secondary Air Injection System
P/B Ð Power Brakes
PCM Ð Powertrain Control Module
PCV Ð Positive Crankcase Ventilation
PRESS Ð Pressure
PROM Ð Programmable Read Only Memory
PNP Ð Park/Neutral Position
P/S Ð Power Steering
PSI Ð Pounds per Square Inch
PSP Ð Power Steering Pressure
Pt. Ð Pint
Pri Ð Primary
PWM Ð Pulse Width Modulate
Qt. Ð Quart
REF Ð Reference
RF Ð Right Front
RFI Ð Radio Frequency Interference
RH Ð Right Hand
RPM Ð Revolutions Per Minute
RPM Sensor Ð Engine Speed Sensor
RPO Ð Regular Production Option
RR Ð Right Rear
RS Ð Right Side
RTV Ð Room Temperature Vulcanizing
RWAL Ð Rear Wheel Antilock Brake
RWD Ð Rear Wheel Drive
SAE Ð Society of Automotive Engineers
Sec Ð Secondary
SFI Ð Sequential Multiport Fuel Injection
SI Ð System International
SIR Ð Supplemental Inflatable Restraint System
SOHC Ð Single Overhead Camshaft
Sol Ð Solenoid
SPEC Ð Specification
Speedo Ð Speedometer
SRS Ð Supplemental Restraint System
ST Ð Start / Scan Tool
Sw Ð Switch
SWB Ð Short Wheel Base
SYN Ð Synchronize
Tach Ð Tachometer
TB Ð Throttle Body
TBI Ð Throttle Body Fuel Injection
TCC Ð Torque Converter Clutch
TCM Ð Transmission Control Module
TDC Ð Top Dead Center
Term Ð Terminal
TEMP Ð Temperature
TODÐ Torque On Demand
TP Ð Throttle Position
TRANS Ð Transmission/Transaxle
TURBO Ð TurbochargerTVRS Ð Television & Radio Suppression
TVV Ð Thermal Vacuum Valve
TWC Ð Three Way Catalytic Converter
3 A/T Ð Three Speed Automatic Transmission/Transaxle
2WD Ð Two Wheel Drive
4 x 2 Ð Two Wheel Drive
U±joint Ð Universal Joint
V Ð Volt(s)
VAC Ð Vacuum
VIN Ð Vehicle Identification Number
VRRRE Ð Vehicle Refrigerant Recovery and Recycling
Equipment
V±ref Ð ECM Reference Voltage
VSS Ð Vehicle Speed Sensor
VSV Ð Vacuum Switch Valve
V±6 Ð Six Cylinder ªVº Engine
V±8 Ð Eight Cylinder ºVº Engine
W Ð Watt(s)
w/ Ð With
w/b Ð Wheel Base
w/o Ð Without
WOT Ð Wide Open Throttle
Service Parts Identification Plate
The Vehicle Information Plate (Service Parts ID plate) is
provided on all vehicle models.
It is located on the center dash wall inside the engine
compartment. The plate lists the VIN (Vehicle
Identification Number), paint information and all
production options and special equipment on the vehicle
when it was shipped from the factory.
905R200002

0B±6MAINTENANCE AND LUBRICATION
Always change the oil and the oil filter as soon as possible
after driving in a dust storm.
Engine Cooling System Inspection
Inspect the coolant/anti±freeze. If the coolant is dirty or
rusty, drain, flush and refill with new coolant. Keep coolant
at the proper mixture for proper freeze protection,
corrosion inhibitor level and best engine operating
temperature. Inspect hoses and replace if cracked,
swollen or deteriorated. Tighten the hose clamps if
equipped with screw±type clamps. Clean outside of
radiator and air conditioning condenser. Wash filler cap
and neck. To help ensure proper operation, a pressure
test of both the cooling system and the cap is also
recommended.
Exhaust System Inspection
Visually inspect the exhaust pipes, muffler, heat shields
and hangers for cracks, deterioration, or damage.
Be alert to any changes in the sound of the exhaust
system or any smell of fumes. These are signs the system
may be leaking or overheating. Repair the system at
once, if these conditions exist. (See also ªEngine Exhaust
Gas Safetyº and ªThree Way Catalytic Converterº in the
Owner's manual.)
Fuel Cap, Fuel Lines, and Fuel Tank
Inspection
Inspect the fuel tank, the fuel cap and the fuel lines every
60,000 miles (96,000 km) for damage which could cause
leakage.
Inspect the fuel cap and the gasket for correct sealing and
physical damage. Replace any damaged parts.
Drive Belt Inspection
Check the serpentine belt driving for cracks, fraying,
wear, and correct tension every 30,000 miles (48,000
km). Replace as necessary.
Wheel Alignment, Balance and Tires
Operation
Uneven or abnormal tire wear, or a pull right or left on a
straight and level road may show the need for a wheel
alignment. A vibration of the steering wheel or seat at
normal highway speeds means a wheel balancing is
needed. Check tire pressure when the tires are ªcoldº
(include the spare).
Maintain pressure as shown in the tire placard, which is
located on the driver's door lock pillar.
Steering System Operation
Be alert for any changes in steering operation. An
inspection or service is needed when the steering wheel
is harder to turn or has too much free play, or if there are
unusual sounds when turning or parking.
Brake Systems Operation
Watch for the ªBRAKEº light coming on. Other signs of
possible brake trouble are such things as repeated pulling
to one side when braking, unusual sounds when braking
or between brake applications, or increased brake pedaltravel. If you note one of these conditions, repair the
system at once.
For convenience, the following should be done when
wheels are removed for rotation: Inspect lines and hoses
for proper hookup, bindings, leaks, crack, chafing etc.
Inspect disc brake pads for wear and rotors for surface
condition.
Inspect other brake parts, including parking brake drums,
linings etc., at the same time. Check parking brake
adjustment.
Inspect the brakes more often if habit or conditions
result in frequent braking.
Parking Brake and Transmission Park
Mechanism Operation
Park on a fairly steep hill and hold the vehicle with the
parking brake only. This checks holding ability. On
automatic transmission vehicles, shifting from ªPº
position to the other positions cannot be made unless the
brake pedal is depressed when the key switch is in the
ªONº position or the engine is running.
WARNING: B E F O R E C H E C K I N G T H E S TA R T E R
SAFETY SWITCH OPERATION BELOW, BE SURE TO
HAVE ENOUGH ROOM AROUND THE VEHICLE.
THEN FIRMLY APPLY BOTH THE PARKING BRAKE
AND THE REGULAR BRAKE. DO NOT USE THE
ACCELERATOR PEDAL. IF THE ENGINE STARTS,
BE READY TO TURN OFF THE KEY PROMPTLY.
TAKE THESE PRECAUTIONS BECAUSE THE
VEHICLE COULD MOVE WITHOUT WARNING AND
POSSIBLY CAUSE PERSONAL INJURY OR
PROPERTY DAMAGE.
Starter Safety Switch Operation
Check by trying to start the engine in each gear while
setting the parking brake and the foot brake. The starter
should crank only in ªPº (Park) or ªNº (Neutral).
Accelerator Linkage Lubrication
Lubricate the accelerator pedal fulcrum pin with chassis
grease.
Steering and Suspension Inspection
Inspect the front and rear suspension and steering
system for damaged, loose or missing parts or signs of
wear. Inspect power steering lines and hoses for proper
hookup, binding, leaks, cracks, chafing, etc.
Body and Chassis Lubrication
Lubricate the key lock cylinders, the hood latch, the hood
and door hinges, the door check link, the parking cable
guides, the underbody contact points, and the linkage.
Propeller Shaft Inspection and Lubrication
Check the propeller shaft flange±to±pinion bolts for
proper torque to 63 Nwm (46 lb ft) for front and rear
propeller shaft.

6E±4
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P1107 MAP Circuit Intermittent Low
Voltage 6E±386. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D T C P 1111 I AT Sensor Circuit Intermittent
High Voltage 6E±388. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1112 IAT Sensor Circuit Intermittent
Low Voltage 6E±391. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1114 ECT Sensor Circuit Intermittent
Low Voltage 6E±393. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1115 ECT Sensor Circuit Intermittent
High Voltage 6E±395. . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code(DTC)P1120-TPS 1
Throttle Position Sensor (TPS1) Output
Abnormal 6E±398. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1125 ETC (Electric Throttle Control)
Limit Performance Mode 6E±401. . . . . . . . . . . . . . . . .
DTC P1133 HO2S Insufficient Switching
Bank 1 Sensor 1 6E±404. . . . . . . . . . . . . . . . . . . . . . . .
DTC P1134 HO2S Transition Time Ratio
Bank 1 Sensor 1 6E±408. . . . . . . . . . . . . . . . . . . . . . . .
DTC P1153 HO2S Insufficient Switching
Bank 2 Sensor 1 6E±412. . . . . . . . . . . . . . . . . . . . . . . .
DTC P1154 HO2S Circuit Transition Time
Ratio Bank 2 Sensor 1 6E±416. . . . . . . . . . . . . . . . . .
DTC P1167 Fuel System Rich During Decel
Fuel Cut Off (Bank 1) 6E±420. . . . . . . . . . . . . . . . . . . .
DTC P1169 Fuel System Rich During Decel
Fuel Cut Off (Bank 2) 6E±422. . . . . . . . . . . . . . . . . . . .
DTC P1171 Fuel System Lean During
Acceleration 6E±424. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1220 Throttle Position Senser2
(TPS2) Circuit Fault 6E±427. . . . . . . . . . . . . . . . . . . . .
DTC P1221 TPS1 ± TPS2 Correlation
(Circuit Performance) 6E±430. . . . . . . . . . . . . . . . . . .
DTC P1271 APS 1± 2 Correlation Error 6E±433. . .
DTC P1272 APS 2 ± 3 Correlation Error 6E±436. . .
DTC P1273 APS 1 ± 3 Correlation Error 6E±439. . . .
DTC P1275 APS 1 Output Fault 6E±442. . . . . . . . . . .
DTC P1280 APS 2 Output Fault 6E±444. . . . . . . . . . .
DTC P1285 APS 3 Output Fault 6E±446. . . . . . . . . . .
DTC P1290 ETC Forced Idle Mode 6E±448. . . . . . . .
DTC P1295 ETC Power Management Mode 6E±451
DTC P1299 ETC Forced Engine Shutdown
Mode 6E±455. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1310 ION Sensing Module Diagnosis 6E±459
DTC P1311 ION Sensing Module SEC
Line 1 Circuit Fault 6E±462. . . . . . . . . . . . . . . . . . . . . .
DTC P1312 ION Sensing Module SEC
Line 2 Circuit Fault 6E±465. . . . . . . . . . . . . . . . . . . . . .
DTC P1326 ION Sensing Module Combustion
Quality Input Circuit Fault 6E±468. . . . . . . . . . . . . . . .
DTC P1340 ION Sensing Module Cylinder ID
Fault (Cylinder Synchronization Fail) 6E±471. . . . . .
DTC P1404 EGR Stuck Closed 6E±474. . . . . . . . . . .
DTC P1441 EVAP System Flow During
Non-Purge 6E±477. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1514 TPS - MAF Correlation Error 6E±480. . . DTC P1515 Command - Actual TPS
Correlation Error 6E±484. . . . . . . . . . . . . . . . . . . . . . . .
DTC P1516 Command - Actual TPS
Correlation Error 6E±487. . . . . . . . . . . . . . . . . . . . . . . .
DTC P1523 Actuator Control Return
Performance 6E±490. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1571 Brake Switch No Operation 6E±493. . . .
DTC P1625 PCM Unexpected Reset 6E±495. . . . . . .
DTC P1635 Reference Voltage # 1 Circuit
Fault 6E±496. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1639 Reference Voltage # 2 Circuit
Fault 6E±498. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1640 Driver-1-Output Circuit Fault
(ODM) 6E±500. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1650 Quad Driver Module ªAº Fault 6E±503. .
Symptom Diagnosis 6E±506. . . . . . . . . . . . . . . . . . . . .
Default Matrix Table 6E±535. . . . . . . . . . . . . . . . . . . . .
On Vehicle Service
Crankshaft Position (CKP) Sensor 6E±538. . . . . . . . .
Engine Coolant Temperature (ECT) Sensor 6E±538.
Heated Oxygen Sensor (HO2S) 6E±539. . . . . . . . . . .
Intake Air Temperature (IAT) Sensor 6E±542. . . . . . .
ION Sensing Module 6E±542. . . . . . . . . . . . . . . . . . . . .
Mass Air Flow (MAF) Sensor 6E±543. . . . . . . . . . . . .
Manifold Absolute Pressure (MAP) Sensor 6E±544.
Malfunction Indicator Lamp (MIL) 6E±545. . . . . . . . . .
Reduced Power Lamp 6E±545. . . . . . . . . . . . . . . . . . .
Powertrain Control Module (PCM) 6E±545. . . . . . . . .
Service Precaution 6E±545. . . . . . . . . . . . . . . . . . . .
EEPROM 6E±547. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Throttle Position (TP) Sensor 6E±547. . . . . . . . . . . . .
Vehicle Speed Sensor (VSS) 6E±548. . . . . . . . . . . . .
Air Cleaner/Air Filter 6E±549. . . . . . . . . . . . . . . . . . . . .
Common Chamber 6E±549. . . . . . . . . . . . . . . . . . . . . .
Accelerator Pedal Replacement 6E±550. . . . . . . . . . .
Accelerator Position Sensor Replacement 6E±551. .
Accelerator Position Sensor Adjustment 6E±551. . . .
Fuel Filler Cap 6E±552. . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Filter 6E±552. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Gauge Unit 6E±553. . . . . . . . . . . . . . . . . . . . . . . .
Fuel Injectors 6E±554. . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Metering System 6E±555. . . . . . . . . . . . . . . . . . . .
Fuel Pump Assembly 6E±555. . . . . . . . . . . . . . . . . . . .
Fuel Pump Relay 6E±556. . . . . . . . . . . . . . . . . . . . . . . .
Fuel Rail Assembly 6E±557. . . . . . . . . . . . . . . . . . . . . .
Fuel Tank 6E±558. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Throttle Body (TB) 6E±558. . . . . . . . . . . . . . . . . . . . . . .
Electronic Ignition System 6E±560. . . . . . . . . . . . . . . .
Catalytic Converter 6E±561. . . . . . . . . . . . . . . . . . . . . .
Air Conditioning Thermo Relay 6E±561. . . . . . . . . . .
EVAP Canister Hoses 6E±561. . . . . . . . . . . . . . . . . . . .
EVAP Canister 6E±562. . . . . . . . . . . . . . . . . . . . . . . . . .
EVAP Canister Vent Solenoid 6E±562. . . . . . . . . . . . .

6E±29
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Undercarriage Component Locator
014RW142
Undercarriage Component Locator Table
Number
NameLocation
1Fuel Pump Assembly and Vapor Pressure
(Fuel Tank Pressure) SensorInstalled in the top of the fuel tank
2Fuel Gauge UnitInstalled in the top of the fuel tank
3Evaporative (EVAP) CanisterOn the top of the bracket that is located behind
the cross member
4Vent Solenoid (EVAP Canister)On the top of the bracket that is located behind
the cross member
5Fuel FilterLocated along the inside of the right frame rail,
ahead of the fuel tank
6Vehicle Speed Sensor (VSS)Protrudes from the transmission housing, just
ahead of the propeller shaft
7Heated Oxygen Sensor (Bank 1, HO2S 1)Threaded into the exhaust pipe behind the
right-hand catalytic converter
8Heated Oxygen Sensor (Bank 1, HO2S 2)Threaded into the exhaust pipe ahead of the
right-hand catalytic converter
9Heated Oxygen Sensor (Bank 2, HO2S 1)Threaded into the exhaust pipe ahead of the
left-hand catalytic converter
10Heated Oxygen Sensor (Bank 2, HO2S 2)Threaded into the exhaust pipe behind the
left-hand catalytic converter

6E±34
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
dissatisfaction. The following list of non-vehicle faults
does not include every possible fault and may not apply
equally to all product lines.
Fuel Quality
Fuel quality is not a new issue for the automotive industry,
but its potential for turning on the MIL (ªCheck Engineº
lamp) with OBD II systems is new.
Fuel additives such as ªdry gasº and ªoctane enhancersº
may affect the performance of the fuel. If this results in an
incomplete combustion or a partial burn, it will show up as
a Misfire DTC P0300. The Reed Vapor Pressure of the
fuel can also create problems in the fuel system,
especially during the spring and fall months when severe
ambient temperature swings occur. A high Reed Vapor
Pressure could show up as a Fuel Trim DTC due to
excessive canister loading. High vapor pressures
generated in the fuel tank can also affect the Evaporative
Emission diagnostic as well.
Using fuel with the wrong octane rating for the vehicle
may cause driveability problems. Many of the major fuel
companies advertise that using ªpremiumº gasoline will
improve the performance of the vehicle. Most premium
fuels use alcohol to increase the octane rating of the fuel.
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 starting
ability and cold driveability of the engine.
Low fuel levels can lead to fuel starvation, lean engine
operation, and eventually engine misfire.
Non-OEM Parts
All of the OBD II diagnostics have been calibrated to run
with OEM parts. Something as simple as a
high-performance exhaust system that affects exhaust
system back pressure could potentially interfere with the
operation of the EGR valve and thereby turn on the MIL
(ªCheck Engineº lamp). Small leaks in the exhaust
system near the post catalyst oxygen sensor can also
cause the MIL (ªCheck Engineº lamp) to turn on.
Aftermarket electronics, such as transceivers, stereos,
and anti-theft devices, may radiate EMI into the control
system if they are improperly installed. This may cause a
false sensor reading and turn on the MIL (ªCheck Engineº
lamp).
Environment
Temporary environmental conditions, such as localized
flooding, will have an effect on the vehicle ignition system.
If the ignition system is rain-soaked, it can temporarily
cause engine misfire and turn on the MIL (ªCheck Engineº
lamp).
Refueling
A new OBD II diagnostic was introduced in 1996 on some
vehicles. This diagnostic checks the integrity of the entire
evaporative emission system. If the vehicle is restarted
after refueling and the fuel cap is not secured correctly,
the on-board diagnostic system will sense this as a
system fault and turn on the MIL (ªCheck Engineº lamp)
with a DTC P0440.Vehicle Marshaling
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 (ªCheck Engineº lamp) with a P0300
Misfire DTC.
Poor Vehicle Maintenance
The sensitivity of OBD II diagnostics will cause the MIL
(ªCheck Engineº lamp) to turn on if the vehicle is not
maintained properly. Restricted air filters, fuel filters, and
crankcase deposits due to lack of oil changes or improper
oil viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD II. Poor vehicle
maintenance can't be classified as a ªnon-vehicle faultº,
but with the sensitivity of OBD II diagnostics, vehicle
maintenance schedules must be more closely followed.
Related System Faults
Many of the OBD II system diagnostics will not run if the
PCM detects a fault on a related system or component.
One example would be that if the PCM detected a Misfire
fault, the diagnostics on the catalytic converter would be
suspended until Misfire fault was repaired. If the Misfire
fault was severe enough, the catalytic converter could be
damaged due to overheating and would never set a
Catalyst DTC until the Misfire fault was repaired and the
Catalyst diagnostic was allowed to run to completion. If
this happens, the customer may have to make two trips to
the dealership in order to repair the vehicle.
Emissions Control Information Label
The engine compartment ªVehicle Emissions Control
Information Labelº contains important emission
specifications and setting procedures. In the upper left
corner is exhaust emission information. This identifies
the emission standard (Federal, California, or Canada) of
the engine, the displacement of the engine in liters, the
class of the vehicle, and the type of fuel metering system.
There is also an illustrated emission components and
vacuum hose schematic.
This label is located in the engine compartment of every
vehicle. If the label has been removed it should be
replaced. It can be ordered from Isuzu Dealership.
Visual / Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any diagnostic
procedure or diagnosing the cause of an emission test
failure. This can often lead to repairing a problem without
further steps. Use the following guidelines when
performing a visual/physical inspection:

Inspect all vacuum hoses for pinches, cuts,
disconnections, and proper routing.

Inspect hoses that are difficult to see behind other
components.

6E±37
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
The Diagnostic Executive records DTCs and turns on the
MIL when emission-related faults occur. It can also turn
off the MIL if the conditions cease which caused the DTC
to set.
Diagnostic Information
The diagnostic charts and functional checks are designed
to locate a faulty circuit or component through a process
of logical decisions. The charts are prepared with the
requirement that the vehicle functioned correctly at the
time of assembly and that there are no multiple faults
present.
There is a continuous self-diagnosis on certain control
functions. This diagnostic capability is complemented by
the diagnostic procedures contained in this manual. The
language of communicating the source of the malfunction
is a system of diagnostic trouble codes. When a
malfunction is detected by the control module, a
diagnostic trouble code is set and the Malfunction
Indicator Lamp (MIL) (ªCheck Engineº lamp) is
illuminated.
Malfunction Indicator Lamp (MIL)
The Malfunction Indicator Lamp (MIL) looks the same as
the MIL you are already familiar with (ªCheck Engineº
lamp). However, OBD II requires that it illuminate under a
strict set of guide lines.
Basically, the MIL is turned on when the PCM detects a
DTC that will impact vehicle emissions.
The MIL is under the control of the Diagnostic Executive.
The MIL will be turned on if an emissions-related
diagnostic test indicates a malfunction has occurred. It
will stay on until the system or component passes the
same test, for three consecutive trips, with no emissions
related faults.
If the vehicle is experiencing a misfire malfunction which
may cause damage to the Three-Way Catalytic
Converter (TWC), the MIL will flash once per second.
This will continue until the vehicle is outside of speed and
load conditions which could cause possible catalyst
damage, and the MIL will stop flashing and remain on
steady.
Extinguishing the MIL
When the MIL is on, the Diagnostic Executive will turn off
the MIL after
three(3) consecutive trips that a ªtest
passedº has been reported for the diagnostic test that
originally caused the MIL to illuminate.
Although the MIL has been turned off, the DTC will remain
in the PCM memory (both Freeze Frame and Failure
Records) until
forty(40) warm-up cycles after no faults
have been completed.
If the MIL was set by either a fuel trim or misfire-related
DTC, additional requirements must be met. In addition to
the requirements stated in the previous paragraph, these
requirements are as follows:

The diagnostic tests that are passed must occur
within 375 RPM of the RPM data stored at the time the
last test failed.

Plus or minus ten (10) percent of the engine load that
was stored at the time the last failed.
Similar engine temperature conditions (warmed up or
warming up ) as those stored at the time the last test
failed.
Meeting these requirements ensures that the fault which
turned on the MIL has been corrected.
The MIL (ªCheck Engineº lamp) is on the instrument
panel and has the following function:

It informs the driver that a fault affects vehicle
emission levels has occurred and that the vehicle
should be taken for service as soon as possible.

As a bulb and system check, the MIL will come ªONº
with the key ªONº and the engine not running. When
the engine is started, the MIL will turn ªOFF.º

When the MIL remains ªONº while the engine is
running, or when a malfunction is suspected due to a
driveability or emissions problem, a Powertrain
On-Board Diagnostic (OBD ll) System Check must be
performed. The procedures for these checks are
given in On-Board Diagnostic (OBD) System Check.
These checks will expose faults which may not be
detected if other diagnostics are performed first.
DTC Types
Each DTC is directly related to a diagnostic test. The
Diagnostic Management System sets DTC based on the
failure of the tests during a trip or trips. Certain tests must
fail two (2) consecutive trips before the DTC is set. The
following are the four (4) types of DTCs and the
characteristics of those codes:

Type A

Emissions related

Requests illumination of the MIL of the first trip with a
fail

Stores a History DTC on the first trip with a fail

Stores a Freeze Frame (if empty)

Stores a Fail Record

Updates the Fail Record each time the diagnostic
test fails

Type B

Emissions related

ªArmedº after one (1) trip with a fail

ªDisarmedº after one (1) trip with a pass

Requests illumination of the MIL on the
second
consecutive trip
with a fail

Stores a History DTC on the second consecutive trip
with a fail (The DTC will be armed after the first fail)

Stores a Freeze Frame on the second consecutive
trip with a fail (if empty)

Stores a Fail Record when the first test fails (not
dependent on
consecutive trip fails)

Updates the Fail Record each time the diagnostic
test fails
(Some special conditions apply to misfire and fuel trim
DTCs)

Type C (if the vehicle is so equipped)

Non-Emissions related

Requests illumination of the Service

Stores a History DTC on the
first trip with a fail

6E±38
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Does not store a Freeze Frame

Stores Fail Record when test fails

Updates the Fail Record each time the diagnostic
test fails

Type D

Non-Emissions related

Not request illumination of any lamp

Stores a History DTC on the
first trip with a fail


Does not store a Freeze Frame

Stores Fail Record when test fails

Updates the Fail Record each time the diagnostic
test fails
IMPORTANT:Only four Fail Records can be stored.
Each Fail Record is for a different DTC. It is possible that
there will not be Fail Records for every DTC if multiple
DTCs are set.
Special Cases of Type B Diagnostic Tests
Unique to the misfire diagnostic, the Diagnostic Executive
has the capability of alerting the vehicle operator to
potentially damaging levels of misfire. If a misfire
condition exists that could potentially damage the
catalytic converter as a result of high misfire levels, the
Diagnostic Executive will command the MIL to ªflashº at a
rate of once per second during those the time that the
catalyst damaging misfire condition is present.
Fuel trim and misfire are special cases of
Type B
diagnostics. Each time a fuel trim or misfire malfunction is
detected, engine load, engine speed, and engine coolant
temperature are recorded.
When the ignition is turned off, the last reported set of
conditions remain stored. During subsequent ignition
cycles, the stored conditions are used as reference for
similar conditions. If a malfunction occurs during two
consecutive trips, the Diagnostic Executive treats the
failure as a normal
Type B diagnostic, and does not use
the stored conditions. However, if a malfunction occurs
on two non-consecutive trips, the stored conditions are
compared with the current conditions. The MIL will then
illuminate under the following conditions:

When the engine load conditions are within 10% of
the previous test that failed.

Engine speed is within 375 rpm, of the previous test
that failed.

Engine coolant temperature is in the same range as
the previous test that failed.Storing and Erasing Freeze Frame Data and Failure
Records
Government regulations require that engine operating
conditions be captured whenever the MIL is illuminated.
The data captured is called Freeze Frame data. The
Freeze Frame data is very similar to a single record of
operating conditions. Whenever the MIL is illuminated,
the corresponding record of operating conditions is
recorded to the Freeze Frame buffer.
Freeze Frame data can only be overwritten with data
associated with a misfire or fuel trim malfunction. Data
from these faults take precedence over data associated
with any other fault. The Freeze Frame data will not be
erased unless the associated history DTC is cleared.
Each time a diagnostic test reports a failure, the current
engine operating conditions are recorded in the
Failure
Records
buffer. A subsequent failure will update the
recorded operating conditions. The following operating
conditions for the diagnostic test which failed
typically
include the following parameters:

Air Fuel Ratio

Air Flow Rate

Fuel Trim

Engine Speed

Engine Load

Engine Coolant Temperature

Vehicle Speed

TP Angle

AP Angle

MAP/BARO

Injector Base Pulse Width

Loop Status
Intermittent Malfunction Indicator Lamp
In the case of an ªintermittentº fault, the MIL (ªCheck
Engineº lamp) may illuminate and then (after three trips)
go ªOFFº. However, the corresponding diagnostic trouble
code will be stored in memory. When unexpected
diagnostic trouble codes appear, check for an intermittent
malfunction.
A diagnostic trouble code may reset. Consult the
ªDiagnostic Aidsº associated with the diagnostic trouble
code. A physical inspection of the applicable sub-system
most often will resolve the problem.
Data Link Connector (DLC)
The provision for communication with the control module
is the Data Link Connector (DLC). It is located at the
lower left of the instrument panel behind a small square
cover. The DLC is used to connect to the Tech 2 Scan
Tool. Some common uses of the Tech 2 are listed below: