HOLDEN GEN III V8 Manual

HOLDEN
GEN III V8 ENGINE MANAGEMENT

HOLDEN LTDA.C.N. 006893 232
SERVICE TRAINING
COPYRIGHT - HOLDEN LTD
Reproduction inwhole orinpartprohibited without written approval
February 2000

GEN IIIV8 ENGINEMANAGEMENT
CONTENTS
SUBJECT
GEN IIIV8 ENGINEMANAGEMENT

GEN IIIV8 ENGINEMANAGEMENT
NOTES
•
GEN IIIV8ENGINE MANAGEMENT

GEN IIIV8 ENGINE MANAGEMENT
GENERAL INFORMATION
The GEN IIIV8 engineuses a Powertrain Control Module(PCM) tocontrol exhaust emissions while maintaining
excellent driveability andfuel economy. The PCM maintains a desired air/fuel ratio atprecisely 14.7to 1.To
maintain a 14.7to 1 airfuel ratio the PCM monitors the output signals from two oxygen sensors. The PCM will
either addor subtract fuel pulses based on the oxygen sensors output signal.This method offeed back fuel
control iscalled closed loop.
Inaddition to fuel control, the PCM alsocontrols the following systems.
•The IgnitionDwell
•The IgnitionTiming
•The IdleSpeed
•The Engine Electric CoolingFans
•The Electric FuelPump
•The Instrument PanelCheck Powertrain lamp
•The A/C Compressor Clutch
•The Automatic Transmission Functions
•The ManualTransmission Reverse Lockout
•Theft Deterrent
The PCM alsointerfaces with other vehicle control modules, such asthe Powertrain Interface Module (PIM),
Instruments, andthe BodyControl Module(BCM). The illustration onthe following page contains a listof the
various operating conditions sensed bythe PCM on the left, and the various systems controlled onthe right.
The PCMhasa built-indiagnostic system that identifies operational problems atwhich time itstores a
Diagnostic Trouble Code (DTC) andon most occasions alerts the driver byilluminating the Check Powertrain
Lamp(CPL) inthe instrument. Ifthe lampcomes on while driving, itdoes notmean that the engineshould be
stopped immediately, butthe cause ofthe lampcoming onshouldbechecked assoon asisreasonably
possible.The PCMhasbuiltinbackup systems thatinallbutthe most severe faults will allow the vehicle to
operate ina nearnormalmanneruntilrepairs can bemade.
Below the instrumentpaneltothe left ofthe steering column isa DatalinkConnector(DLC)which isused by
the assembly plantfor a computer "check-out" of the PCM system. The DLCisalsoused inservice to help
diagnose the system usingTech 2.
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POWERTRAIN CONTROL MODULE
The Powertrain Control Module (PCM), islocated inthe engine compartment and constantly monitors the
information fromvarious sensors, and controls the engine and transmission operation, dependant on the
information received fromthese sensors The PCM performs the diagnostic functionof the system Itcan
recognise operational problems, alert the driver through the Check Powertrain Lampand store a Diagnostic
Trouble Code(s) that willidentify problem areas to aid the technician inmaking repairs The PCM supplies either
abuffered 5 or 12voltsto power various sensors or switches This isdone through resistance's inthe PCM
which are so high invalue that a testlight will not light when connected to the circuitInsome cases, even an
ordinary voltmeter will notgive an accurate reading because the meter's internal resistance istoo low
A10Meg Ohm input impedance digital voltmeter isrequired to assure accurate voltage readings.
The PCM controls output circuits such as the injectors, IAC, and various relays, etc by controlling the earth
circuit through transistors or a device called a "Driver" inthe PCM The two exceptions to this are the fuelpump
relay control circuit and the automatic transmission pressure control solenoid (PCS) The fuelpump relay isthe
only PCM controlled circuit where the PCM controls the +12volts sent to the coil of the relay The earth side of
the fuelpump relay coil isconnected to engine earth The PCM supplies current to the PCS and monitors how
much current returns to the PCM on a separate terminal The PCM also receives and transmits serial data via
the Powertrain Interface Module (PIM) and the serial data bus
The Gen IIIPCM does not contain a removable PROM, ituses an EEPROM (Flash Memory) which isnon
removable The PCM isprogrammed from the factorywith the proper calibrations forvehicle operation Inthe
event that the PCM isreplaced, or anupdated calibration isrequired to correcta vehicle's operating condition,
the new PCM or the new calibration will have to be down loaded to the PCM EEPROM (Flash Memory) Down
loading isaccomplished through the vehicle DLC using the TECH 2 Service Programming System (SPS) and
the Technical Information System (TIS)
The service replacement PCM EEPROM (Flash Memory) will not be programmed DTC P0601 and P0602
indicates the FlashMemory isnot programmed or has malfunctioned
PCM Security Link
Once the PCM, PIM andor BCM have been replaced, the new PCM, PIM and BCM must be security linked to
each other using Tech 2 and TIS
PCM Power Supplies
Battery voltage isapplied to PCM terminals J1-20and J1-57at all times via fuse F31 and ignition voltage is
applied to PCM terminal J1-19via fuse F14whenever the ignition switch isinthe ON or START positions The
PCM isearthed fromterminalsJ1-01,J1-40, J2-01 andJ2-40 to earth points E5and E15
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GEN IIIV8 ENGINE MANAGEMENT
PCM FiveVolt Reference Circuits
The PCM has two fivevolt reference circuits The fivevolt reference circuit number one supplies fivevolts to the
following sensors
•The Throttle Position Sensor (J1 -08)
•The Manifold Absolute Pressure Sensor (J1-48)
•OilPressure Sensor (J1-07)
The fivevolt reference circuit number two supplies fivevolts to the following sensor
•The A/C Pressure Sensor (J1-45)
The PCM monitors the voltage on the 5 0 volt reference circuit This DTC sets ifthe voltage isout of range
Afailure ina FiveVolt Reference Circuits will set one of the following DTCs:
DTCP1635Five Volt Reference #1 Circuit
Conditions for running DTCP1635
•The ignition ison
Conditions for setting DTC P1635
•The fivevolt reference #1circuit isout of range
•All of the above conditions are present forgreater than 2 seconds
Action taken when DTCP1635Sets
•The PCM illuminates the Check Powertrain Lampwhen the diagnostic runs and fails
•The PCM records the operating conditions atthe time the diagnostic fails The PCM stores this information
inthe Freeze Frame/Failure Records
Conditions for clearing the Check Powertrain Lamp and DTC P1635
•The PCM turns the Check Powertrain LampOFF after one ignition cycle that the diagnostic runs and does
notfail
•A last test failed (Current DTC) clears when the diagnostic runs and does notfail
DTCP1639Five Volt Reference #2 Circuit
Conditions for running DTCP1639
•The ignition ison
Conditions for setting DTC P1639
•The fivevolt reference #2 circuit isout of range
•All of the above conditions are present forgreater than 2 seconds
Action taken when DTCP1639Sets
•The PCM illuminates the Check Powertrain Lampwhen the diagnostic runs and fails
•The PCM records the operating conditions atthe time the diagnostic fails The PCM stores this information
inthe Freeze Frame/Failure Records
Conditions for clearing the Check Powertrain Lamp and DTCP1639
•The PCM turns the Check Powertrain Lamp OFF after one ignition cycle that the diagnostic runs anddoes
not fail
•A last test failed (Current DTC)clears when the diagnostic runs and does not fail
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GEN IIIV8 ENGINE MANAGEMENT
DIAGNOSIS
The Rowel-train Management Section of the Service Manual iswhere to start alldnveability and emissions
diagnosis Once you have read andunderstood the General Information Section which contains reference
material wiring diagrams, PCM terminal end views and normal voltages, andcomponent locations (Remember,
this information isfor reference, do notstart diagnosis using these pages) Always start diagnosis on the page
titled On-Board Diagnostic System Check This check firstverifiesthat the diagnostic circuits are operating
properly andthen sends you to the correct service manual page fordiagnosis
Ifthe initialsteps inthe On-Board Diagnostic System Check reveal a problem, or ifthe engine does not start,
you will beusing one or more A charts fordiagnosis Again, the On-Board Diagnostic System Check will send
you to the correct chart These charts follow the On-Board Diagnostic System check and diagnose both
fundamental PCM diagnostics and problems that prevent the engine from starting
Ifthe On-Board DiagnosticSystem Check shows that Diagnostic Trouble Codes (DTC) have been stored,
proceed to the appropriate Diagnostic Trouble Code diagnosis pages Ifmore than one diagnostic trouble code
hasbeen stored, always start diagnosis with the lowest diagnostic trouble code number and work upward
Diagnostic trouble code diagnosis pages start immediately after the A chart pages
Diagnostic Precautions
The following requirements mustbeobserved when working on vehicles:
1.Before removing any PCM system component, disconnect the battery earth lead
2.Never start the engine without the battery being solidly connected
3.Never separate the battery from the on board electrical system while the engine isrunning
4.When charging the battery, disconnect itfrom the vehicle's electrical system
5.Never subject the PCMto temperatures above 80degrees C i e paintoven Always remove control unitfirst
ifthis temperature isto be exceeded
6.Ensure that allcable harness plugs are connected solidly and that battery terminals are thoroughly clean
7.The PCM harness connectors are designed to fit inonly one way, there are indexing tabs and slots on both
halves of the connector Forcing the connector intoplace isnotnecessary ifitisbeing installed with the
proper orientation Failure to take care to match the indexing tabs and slots to ensure the connector isbeing
installed correctly can cause damage to the connector, the module, or other vehicle components or
systems
8.Never connect or disconnect cable harness plugatthe PCM when the ignitionisswitched on
9.Before attempting any electric arc welding on the vehicle, disconnect the battery leads and the PCM
connectors
10.When steam cleaning engines, do notdirect the steam cleaning nozzle at PCM system components Ifthis
happens, corrosion of the terminals can take place
11.Use only the test equipment specified inthe diagnostic charts, since other test equipment may either give
incorrect results or damage good components
12.All voltage measurements using a voltmeter must usea digitalvoltmeter with aninternalimpedance rating
of atleast 10million ohms per volt (10meg ohms)
13.When a test lightisspecified, a low-power test lightmust beused Donot use a high- wattage test light
While a particular brand of test lightisnotsuggested, a simple test on any test lightwillensure itto be OK
forPCM circuit testing Connect anaccurate ammeter (such as the high-impedance digital multimeter) in
series with the test lightbeingtested, andpower the test light-ammeter circuit with the vehicle battery
Ifthe ammeter indicates tessthan3/10amp current flow (03 A or 300mA), the test lightisOK to use
Ifthe ammeter indicates more than 3/10amp current flow (03 A or 300mA), the test lightisNOT OK to
use
Blocking Drive Wheels
The vehicle drive wheels should always beblocked andparking brake firmly set while checking the system
Visual/Physical Inspection
Acareful visual and physical inspectionmust beperformed as part of any diagnostic procedure or in
finding the cause of an emissions test failure. This can often leadto fixing a problem without further steps
Inspect allelectrical wires for correct routing, pinches, cuts, or disconnections Besure to inspect wires that are
difficult to see beneath the aircleaner, compressor, generator, etc Inspect allthe wires inthe engine
compartment forproper connections, burned or chafed spots, pinched wires, or contact with sharp edges or hot
exhaust manifolds This visual/physical inspection isvery important Itmust bedone carefully andthoroughly
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GEN IIIV8 ENGINE MANAGEMENT
Basic Knowledge and Tools Required
To usethe VT Series Service Manualeffectively, a general understanding of basic electrical circuits and circuit
testing tools isrequired You should be familiar with wiring diagrams, the meaning ofvoltage, ohms, amps, the
basic theories ofelectricity, and understand what happens inanopen or shorted wire
To perform system diagnosis, the useof a Tech 2 isrequired A test light, digital volt-ohmmeter with 10
megohms impedance, vacuum gauge, and jumper wires are also required Please become acquainted with the
tools andtheir use before attempting to diagnose a vehicle
ElectrostaticDischargeDamage
Electronic components used incontrol systems are often designed to carry very low voltage, andare very
susceptible to damage caused by electrostatic discharge Itispossible forless than 100volts of static electricity
to cause damage to some electronic components Bycomparison, ittakes as much as 4,000 volts fora person
to even feel the zap of a static discharge
There are several ways fora person to become statically charged The most common methods of charging are
by friction andby induction An example of charging by frictionisa person sliding across a car seat, inwhich a
charge of as much as 25,000 volts can buildup
Charging by induction occurs when a person with well insulated shoes stands near a highly charged object and
momentarily touches earth Charges of the same polarity are drained off,leaving the person highly charged with
the opposite polarity Static charges of either type can cause damage, therefore, itisimportant to use care when
handling and testing electronic components
NOTE:To prevent possible Electrostatic Discharge damage
•DoNottouch the PCM connector pins
DIAGNOSTIC INFORMATION
The diagnostic charts and functional checks inthe Service Manual are designed to locate a faulty circuit or
component through logicbased on the process of elimination The charts are prepared with the requirement that
the vehicle
•Functioned correctly at the time of assembly
•There are no multiple faults
•The problem currently exists
The PCM performs a continual self-diagnosis on certain control functions This diagnostic capability is
complemented by the diagnostic procedures contained inthe Service Manual The PCM's language for
communicating the source of a malfunction isa system of Diagnostic Trouble Codes (DTCs) The diagnostic
trouble codes are four digit(POXXXor P1XXX)When a fault isdetected by the PCM, a diagnostic trouble code
isset and the Check Powertrain lampmay beilluminated
Self-Diagnostics
The PCMperforms system self diagnostics, and can detect and often isolate system failures When a failure is
detected, the PCM sets a DTC that represents that failure andmay or may notturn on the Check Powertrain
Lamp
Check Powertrain Lamp
The Check Powertrain Lampisa Malfunction Indicator Lamp(MIL) andislocated inthe instrument paneland
has the following functions
•Itisused as a bulbcheck, itwill come on for two seconds when the ignitionisturned on
•Itinforms the driver that a problem hasoccurred andthat the vehicle should be taken for service as soon as
isreasonably possible
As a bulband system check, the Check Powertrain lampwill come on for two seconds when the ignitionis
turned onIfthe Check Powertrain lampremains illuminated, the self-diagnostic system hasdetected a problem
Ifthe problem goes away, the Check Powertrain lampwill goout inmost cases after 10seconds, buta
Diagnostic Trouble Code will bestored inthe PCM
When the Check Powertrain lampremains on while the engine isrunning, or when a malfunction issuspected
due to a dnveability or emissions problem, anOn-Board Diagnostic System Check must beperformed. The
procedure forthis check isgiven inthe Service Manual These checks will expose malfunctions which may not
bedetected ifother diagnostics are performed prematurely
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GEN IIIV8 ENGINE MANAGEMENT
Intermittent Check Powertrain Lamp
Inthe case of anintermittent problem, the Check Powertrain lampmay light forten seconds and then will go
out However, the corresponding Diagnostic Trouble Code (DTC) will be stored inthe memory ofthe PCM The
DTCwill remain stored inthe PCM memory until the Tech 2 erases itWhen unexpected DTCs appear during
the diagnostic trouble code reading process, one can assume that these DTCs were set by anintermittent
malfunction andcould behelpful indiagnosing the system
An intermittent diagnostic trouble code may or may not re-set Ifitisanintermittent failure, a Diagnostic Trouble
Code Chart isnot used Consult the Diagnostic Aids on the page facing the diagnostic chart corresponding to
the intermittent diagnostic trouble code The Symptoms section also covers the topic of intermittents A physical
inspection of the applicable sub-system most often will resolve the problem The Tech 2 also hasseveral
features which can helpwith diagnosing intermittents, such as the Wiring Harness integrity test
STRATEGY BASED DIAGNOSTICS
The strategy based diagnostic isa uniform approach to repair allElectrical/Electronic systems The diagnostic
flowcan always beused to resolve anElectrical/Electronic system problem andisa starting point when repairs
are necessary The steps below are defined to instruct the technician how to proceed with a diagnostic process
Steps below also refer to step numbers found on the Strategy Based Diagnostic table
1.Verify the Driver Concern: To verifythe driver concern, the technician should know the normal operation
of the system
2. Preliminary Check: Conduct a thorough visual and operational inspection, review the service history,
detect unusual sounds or odours, and gather diagnostic trouble code information to achieve effectiverepair
3. Service information (Manual) System Check(s): System checks verify proper operation of the system
This will leadthe technician inanorganised approach to diagnostics
4. Check Bulletins and Other Service Information: This should include, Techlines, AllDealer letters, and
Service Training Publications
5. Service Diagnostics (Paper/Electronic)
5.1 DTCStored: Follow the designed DTC table exactly to make aneffective repair
5.2 Symptom, NoDTC:Select the symptom from the symptom tables and follow the diagnostic paths or
suggestions to complete the repair, or refer to the applicable component/system checks inSection 6C3-
2C inthe Service Manual
5.3NoPublishedDiagnostics: Analyse the complaint and develop a plan for diagnostics Utilise the wiring
diagrams and theory of operation
CallTechnical Assistance forsimilar cases where repair history may be available Combine technician
knowledge with efficient use of the available service information
5.4 Intermittent faults: Conditions that are notalways present are intermittent To resolve intermittents,
perform the following steps
5.4.1 Observe history DTCs, DTCmodes andFreeze Frame data
5.4.2 Evaluate the symptoms and conditions described by the driver
5.4.3 Use a check sheet or other method to identify the circuit or electrical system component
5.4.4 Follow the suggestions forintermittent diagnosis found inthe service documentation
The Tech 2 andDMM have data capturing capabilities that can assist indetection of intermittents
5.5 Vehicle Operates As Designed/No Trouble Found:This condition exists when the vehicle isfound to
beoperating normally The condition described by the driver may benormal Verifyagainst another
vehicle that isoperating normally The condition may beintermittent Contact Technical Assistance ifthe
concern iscommon Verifythe complaint under the conditions described bythe driver before releasing
the vehicle
6.Re-examine the Concern: When the complaint cannot besuccessfully found or isolated, a re-evaluation is
necessary The complaint should bere-verified and could beintermittent or normal as per step 5 3 or 5 5
7.Repair and Verification Tests: Afterisolating the cause, the repair should bemade Then validate for
proper operation and verify that the symptom hasbeen corrected This may involve road testing or other
methods to verify the complaint has been resolved under the following conditions
•Conditions noted by the driver
•Ifa DTC was diagnosed, verify a repair by duplicating conditions present when a DTCwas set as noted
inthe Freeze Frame/Failure Records data
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POWERTRAIN ON-BOARD DIAGNOSTIC SYSTEM CHECK
Afterthe visual/physical underhood inspection, the On-Board Diagnostic System Check isthe starting point for
alldiagnostic procedures or finding the cause of anemissions failure
All Diagnostic procedures must always begin with the On-board Diagnostic System Check
Diagnostic procedures must begin with the On-Board Diagnostic System Check, which represents an organised
approach foridentifying system problems
The ON-BOARD DIAGNOSTIC SYSTEM CHECK makes aninitial check of the system, then will direct the
technician to other charts inthe Service Manual Itmust be used as a starting pointfor allprocedures The
entire diagnostic section inthe VT Series Service Manual isset upina specific order, that is,the ON-BOARD
DIAGNOSTIC SYSTEM CHECK will leadthe technician to other charts, and those charts may lead to still other
charts THE SEQUENCE MUST BEFOLLOWED. The engine/transmission control system uses many input
signals and controls many output functions Ifthe correct diagnostic sequence isnotfollowed, incorrect
diagnosis and replacement of good parts may happen
Diagnostic charts incorporate diagnosis procedures using a Tech 2 where possible This Tech 2 isa small
hand-held computer initself Its job isto give information to a technician about what ishappening inthe
engine/transmission management system
The DataLinkConnector (DLC) isused by the assembly plant to perform end of linetests This connector can
also beused by technicians to monitor certain inputs andoutputs as seen by the Powertrain Control Module
The Tech 2 reads and displays the information (serial data) supplied to the data link connector from the
Powertrain Control Module(PCM)
The correct procedure to diagnose a problem isto follow three basic steps
1.Are the On-Board Diagnostics working? This isdetermined by performing the On-Board Diagnostic System
Check Since this isthe starting point for the diagnostic procedures or finding the cause of a failure, always
beginhere
Ifthe On-Board Diagnostics are notworking, the On-Board Diagnostic System Check will leadto a
diagnostic chart to correct the problem Ifthe On-Board Diagnostics are working correctly,the next step is
2.Isthere a Diagnostic Trouble Code stored7Ifa diagnostic trouble code isstored, go directly to the
numbered diagnostic trouble code chart This will determine ifthe fault isstill present Ifnodiagnostic
trouble code isstored, then
3.Observe Serial Data transmitted by the PCM This involves reading the information available on the Serial
DataStream with a Tech 2 Information on this tool and the meaning of the various displays can be found in
the succeeding paragraphs Typical data readings undera particular operating condition can be found on
the Tech 2 Data page
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SYSTEM DIAGNOSTICS
The PCM hastwo functions to perform
1.Itmust beable to control the vehicle systems using sensor inputs and internal software
2.Itmust also beable to perform system diagnostics
Both management systems have the ability to share information and communicate
The PCM diagnostics are controlled by the diagnostic management system The diagnostic management
system must beable to
•Perform diagnostic testing
•Record the results of diagnostic testing
•Request test failactions
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DiagnosticTesting
One of the primary functions of the diagnostic management system isto perform diagnostic testing of system
operation The Diagnostic isthe test or tests run on a system or component to determine ifitisoperating
according to specifications The different types of diagnostic tests include
•Passive
•Active
•Intrusive
Passive testing simply monitors the system or components during operation During Active testing, the PCM
controls the system or component ina specific action while monitoring takes place The PCM may perform
active tests as a result of failed passive tests The intrusive test isa special type of active test that involves an
action by the PCM that may affectvehicle performance or emissions
The Enable Criteria are the exact conditions required fora diagnostic to be run The enable criteriaforany DTC
are listed under Conditions to Setas partof the diagnostic information inthe Service Manual
Diagnostic testing occurs during a trip A Trip isa key-on cycle inwhich allthe enable criteria fora given
diagnostic test are met, followed by a key-off / power-down Since the enable criteriaforeach DTCisdifferent, a
trip foreach DTC isdifferent
The PCM counts warm-up cycles instead of key cycles to clear DTCs A warm-Up Cycle isachieved when the
engine coolant temperature rises atleast 22°C fromstart-up and achieves a minimum temperature of 71 °C
The PCM also hasthe ability to learn from the results of its diagnostic testing The PCM internally charts the
results of diagnostic testing over a period of time and creates a baseline - the normal results of a test This is
called Statistical Filtering Byusing this learning capability, the PCM isable to filterout information that could
cause a falseDTC to set
NOTE: The loss of battery power to the PCM will result inthe loss of "learned" information. The PCM
will perform an aggressive testing schedule to relearn information. This mode of testing iscalled Quick
Learn and isnotnoticeable inmost cases.
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Diagnostic Information
The diagnostic tables and functional checks inthe Service Manual are designed to locate a faulty circuit or
component through logic based on the process of elimination. The tables inthe Service Manual are prepared
with the understanding that the vehicle:
•Functioned correctly atthe time of assembly.
•There are nomultiple faults.
•The problem currently exists.
The PCM performs a continual self-diagnosis on certain control functions. The PCM indicates the source of a
fault through the use of Diagnostic Trouble Codes (DTCs). The DTCs are fourdigit codes (POXXX or P1XXX).
When a fault isdetected by the PCM, a DTCwill be set and stored inthe memory of the PCM and the Check
Powertrain Lamp may illuminate.
Recording Test Results (Diagnostic Executive)
The Diagnostic Executive isa unique segment of the PCM software which isdesigned to co-ordinate and
prioritise the diagnostic procedures as well as define the protocol forrecording and displaying their results. The
main responsibilities of the Diagnostic Executive are:
•DTC Information
DTCInformation indicates the status of the diagnostic testing fora specific DTC. Itcontains information on
pass / failstatus of the test, when the diagnostic test failed and ifthe DTCisrequesting the illumination of
the Check Powertrain Lamp.
•Freeze Frame / Failure Records
Freeze frame / failure records are stored any time a diagnostic test fails. The PCM has the ability to store up
to six freezeframe / failure records. When a diagnostic test fails, records are stored inthe firstfail position. If
adifferent diagnostic test fails, a second failrecord position. Additional failed diagnostic tests fordifferent
DTCs also store failrecords until the failrecord memory isfull. The PCM hasthe ability to store six freeze
frame / failure records, ifmore than six DTC freeze frame failure records are stored, the fail records are
replaced on a firstin,firstout basis.
The freezeframe / failure records data list has32 parameters for data capture. When a DTCisset, the PCM
will capture all32 parameters atthe time the DTC islogged.
Inaddition to the regular data list parameters found inthe freezeframe / failure records data list, there is
additional information available about the DTCdiagnostics:
•First Odometer - Vehicle kilometre value when the DTCfailure firstrecorded.
•Last Odometer - Vehicle kilometre value when the DTC failisrecorded.
•FailCounter - Number of ignitioncycles with failure (DTC was set).
•Pass Counter - Number of ignitioncycles with diagnostic passes (DTC was not set again).
•NotRun Counter - Number ofignition cycles without diagnostic run(DTC conditions were not tested).
•System Status
The System Status (I/M Flag)stores information on which diagnostics have run.Ifa system diagnostic has
run, the system status flag (yes/no) will beset.
•Warm-up Cycles
Records the number of warm-up cycles that have been achieved since the DTCwas set.
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