2000 DODGE NEON oxygen

²Engine in closed loop
²Operating in Similar Conditions Window
²Short Term multiplied by Long Term less than
threshold
²Less than threshold for a predetermined time
If all of the previous criteria are met, the PCM will
count a good trip (three required) and turn off the
MIL.
Misfire Good Trip
If the following conditions are met the PCM will
count one good trip (three required) in order to turn
off the MIL:
²Operating in Similar Condition Window
²1000 engine revolutions with no misfire
Alternate Good Trip
Alternate Good Trips are used in place of Global
Good Trips for Comprehensive Components and
Major Monitors. If the Task Manager cannot run a
Global Good Trip because a component fault is stop-
ping the monitor from running, it will attempt to
count an Alternate Good Trip.
The Task Manager counts an Alternate Good Trip
for Comprehensive components when the following
conditions are met:
²Two minutes of engine run time
²No other faults occur
The Task Manager counts an Alternate Good Trip
for a Major Monitor when the monitor runs and
passes. Only the Major Monitor that failed needs to
pass to count an Alternate Good Trip.
Warm-Up Cycles
Once the MIL has been extinguished by the Good
Trip Counter, the PCM automatically switches to a
Warm-Up Cycle Counter that can be viewed on the
DRB III. Warm-Up Cycles are used to erase DTCs
and Freeze Frames. Forty Warm-Up cycles must
occur in order for the PCM to self-erase a DTC and
Freeze Frame. A Warm-Up Cycle is defined as fol-
lows:
²Engine coolant temperature must start below
and rise above 160É F
²Engine coolant temperature must rise by 40É F
²No further faults occur
Freeze Frame Data Storage
Once a failure occurs, the Task Manager records
several engine operating conditions and stores it in a
Freeze Frame. The Freeze Frame is considered one
frame of information taken by an on-board data
recorder. When a fault occurs, the PCM stores the
input data from various sensors so that technicians
can determine under what vehicle operating condi-
tions the failure occurred.
The data stored in Freeze Frame is usually
recorded when a system fails the first time for twotrip faults. Freeze Frame data will only be overwrit-
ten by a different fault with a higher priority.
CAUTION: Erasing DTCs, either with the DRB III or
by disconnecting the battery, also clears all Freeze
Frame data.
Similar Conditions Window
The Similar Conditions Window displays informa-
tion about engine operation during a monitor. Abso-
lute MAP (engine load) and Engine RPM are stored
in this window when a failure occurs. There are two
different Similar conditions Windows: Fuel System
and Misfire.
FUEL SYSTEM
²Fuel System Similar Conditions WindowÐ
An indicator that 'Absolute MAP When Fuel Sys Fail'
and 'RPM When Fuel Sys Failed' are all in the same
range when the failure occurred. Indicated by switch-
ing from 'NO' to 'YES'.
²Absolute MAP When Fuel Sys FailÐ The
stored MAP reading at the time of failure. Informs
the user at what engine load the failure occurred.
²Absolute MAPÐ A live reading of engine load
to aid the user in accessing the Similar Conditions
Window.
²RPM When Fuel Sys FailÐ The stored RPM
reading at the time of failure. Informs the user at
what engine RPM the failure occurred.
²Engine RPMÐ A live reading of engine RPM
to aid the user in accessing the Similar Conditions
Window.
²Adaptive Memory FactorÐ The PCM uti-
lizes both Short Term Compensation and Long Term
Adaptive to calculate the Adaptive Memory Factor
for total fuel correction.
²Upstream O2S VoltsÐ A live reading of the
Oxygen Sensor to indicate its performance. For
example, stuck lean, stuck rich, etc.
²SCW Time in Window (Similar Conditions
Window Time in Window)Ð A timer used by the
PCM that indicates that, after all Similar Conditions
have been met, if there has been enough good engine
running time in the SCW without failure detected.
This timer is used to increment a Good Trip.
²Fuel System Good Trip CounterÐATrip
Counter used to turn OFF the MIL for Fuel System
DTCs. To increment a Fuel System Good Trip, the
engine must be in the Similar Conditions Window,
Adaptive Memory Factor must be less than cali-
brated threshold and the Adaptive Memory Factor
must stay below that threshold for a calibrated
amount of time.
²Test Done This TripÐ Indicates that the
monitor has already been run and completed during
the current trip.
25 - 4 EMISSION CONTROL SYSTEMSPL
DESCRIPTION AND OPERATION (Continued)

OPERATION
BULB CHECK
Each time the ignition key is turned to the ON
position, the malfunction indicator (check engine)
lamp on the instrument panel should illuminate for
approximately 2 seconds then go out. This is done for
a bulb check.
OBTAINING DTC'S USING DRB SCAN TOOL
(1) Connect the DRB scan tool to the data link
(diagnostic) connector. This connector is located inthe passenger compartment; at the lower edge of
instrument panel; near the steering column.
(2) Turn the ignition switch on and access the
ªRead Faultº screen.
(3) Record all the DTC's and ªfreeze frameº infor-
mation shown on the DRB scan tool.
(4) To erase DTC's, use the ªErase Trouble Codeº
data screen on the DRB scan tool.Do not erase any
DTC's until problems have been investigated
and repairs have been performed.
DIAGNOSTIC TROUBLE CODE DESCRIPTIONS
(M) Check Engine Lamp (MIL) will illuminate during engine operation if this Diagnostic Trouble Code was recorded.
(G) Generator Lamp Illuminated
GENERIC SCAN
TOOL CODEDRB SCAN TOOL DISPLAY DESCRIPTION OF DIAGNOSTIC TROUBLE CODE
P0106 (M) Barometric Pressure Out of Range MAP sensor input voltage out of an acceptable range
detected during reading of barometric pressure at
key-on.
P0107 (M) Map Sensor Voltage Too Low MAP sensor input below minimum acceptable voltage.
P0108 (M) Map Sensor Voltage Too High MAP sensor input above maximum acceptable voltage.
P0112 (M) Intake Air Temp Sensor Voltage Low Intake air (charge) temperature sensor input below the
minimum acceptable voltage.
P0113 (M) Intake Air Temp Sensor Voltage
HighIntake air (charge) temperature sensor input above the
maximum acceptable voltage.
P0116 A rationatilty error has been detected in the coolant
temp sensor.
P0117 (M) ECT Sensor Voltage Too Low Engine coolant temperature sensor input below the
minimum acceptable voltage.
P0118 (M) ECT Sensor Voltage Too High Engine coolant temperature sensor input above the
maximum acceptable voltage.
P0121 (M) TPS Voltage Does Not Agree With
MAPTPS signal does not correlate to MAP sensor signal.
P0122 (M) Throttle Position Sensor Voltage
LowThrottle position sensor input below the acceptable
voltage range.
P0123 (M) Throttle Position Sensor Voltage
HighThrottle position sensor input above the maximum
acceptable voltage.
P0125 (M) Closed Loop Temp Not Reached Time to enter Closed Loop Operation (Fuel Control) is
excessive.
P0130 1/1 O2 Sensor Heater Relay Circuit An open or shorted condition detected in the ASD or
CNG shutoff relay control ckt.
P0131 (M) 1/1 O2 Sensor Shorted To Ground Oxygen sensor input voltage maintained below normal
operating range.
P0132 (M) 1/1 O2 Sensor Shorted To Voltage Oxygen sensor input voltage maintained above normal
operating range.
P0133 (M) 1/1 O2 Sensor Slow Response Oxygen sensor response slower than minimum required
switching frequency.
25 - 6 EMISSION CONTROL SYSTEMSPL
DESCRIPTION AND OPERATION (Continued)

(M) Check Engine Lamp (MIL) will illuminate during engine operation if this Diagnostic Trouble Code was recorded.
P0134 (M) 1/1 O2 Sensor Stays at Center Neither rich or lean condition is detected from the
oxygen sensor input.
P0135 (M) 1/1 O2 Sensor Heater Failure Oxygen sensor heater element malfunction.
P0136 1/2 O2 Sensor Heater Relay Circuit An open or shorted condition detected in the ASD or
CNG shutoff relay control ckt.
P0137 (M) 1/2 O2 Sensor Shorted To Ground Oxygen sensor input voltage maintained below normal
operating range.
P0138 (M) 1/2 O2 Sensor Shorted To Voltage Oxygen sensor input voltage maintained above normal
operating range.
P0139 (M) 1/2 O2 Sensor Slow Response Oxygen sensor response not as expected.
P0140 (M) 1/2 O2 Sensor Stays at Center Neither rich or lean condition is detected from the
oxygen sensor.
P0141 (M) 1/2 O2 Sensor Heater Failure Oxygen sensor heater element malfunction.
P0143 1/3 O2 Sensor Shorted To Ground Oxygen sensor input voltage maintained below normal
operating range.
P0144 1/3 O2 Sensor Shorted To Voltage Oxygen sensor input voltage maintained above normal
operating range.
P0145 1/3 O2 Sensor Slow Response Oxygen sensor response slower than minimum required
switching frequency.
P0146 1/3 O2 Sensor Stays at Center Neither rich or lean condition is detected from the
oxygen sensor.
P0147 1/3 O2 Sensor Heater Failure Oxygen sensor heater element malfunction.
P0151 (M) 2/1 O2 Sensor Shorted To Ground Oxygen sensor input voltage maintained below normal
operating range.
P0152 (M) 2/1 O2 Sensor Shorted To Voltage Oxygen sensor input voltage sustained above normal
operating range.
P0153 (M) 2/1 O2 Sensor Slow Response Oxygen sensor response slower than minimum required
switching frequency.
P0154 (M) 2/1 O2 Sensor Stays at Center Neither rich or lean condition is detected from the
oxygen sensor.
P0155 (M) 2/1 O2 Sensor Heater Failure Oxygen sensor heater element malfunction.
P0157 (M) 2/2 O2 Sensor Shorted To Ground Oxygen sensor input voltage maintained below normal
operating range.
P0158 (M) 2/2 O2 Sensor Shorted To Voltage Oxygen sensor input voltage maintained above normal
operating range.
P0159 2/2 O2 Sensor Slow Response Oxygen sensor response slower than minimum required
switching frequency.
P0160 (M) 2/2 O2 Sensor Stays at Center Neither rich or lean condition is detected from the
oxygen sensor.
P0161 (M) 2/2 O2 Sensor Heater Failure Oxygen sensor heater element malfunction.
P0165 Starter Relay Control Circuit An open or shorted condition detected in the starter
relay control circuit.
P0171 (M) 1/1 Fuel System Lean A lean air/fuel mixture has been indicated by an
abnormally rich correction factor.
P0172 (M) 1/1 Fuel System Rich A rich air/fuel mixture has been indicated by an
abnormally lean correction factor.
PLEMISSION CONTROL SYSTEMS 25 - 7
DESCRIPTION AND OPERATION (Continued)

(M) Check Engine Lamp (MIL) will illuminate during engine operation if this Diagnostic Trouble Code was recorded.
P0740 (M) Torq Con Clu, No RPM Drop at
LockupRelationship between engine and vehicle speeds
indicated failure of torque convertor clutch lock-up
system (TCC/PTU sol).
P0743 Torque Converter Clutch Solenoid/
Trans Relay CircuitsAn open or shorted condition detected in the torque
converter clutch (part throttle unlock) solenoid control
circuit. Shift solenoid C electrical fault - Aisin
transmission
P0748 Governor Pressur Sol Control/Trans
Relay CircuitsAn open or shorted condition detected in the Governor
Pressure Solenoid circuit or Trans Relay Circuit in JTEC
RE transmissions.
P0751 O/D Switch Pressed (Lo) More
Than 5 MinutesOverdrive override switch input is in a prolonged
depressed state.
P0753 Trans 3-4 Shift Sol/Trans Relay
CircuitsAn open or shorted condition detected in the overdrive
solenoid control circuit or Trans Relay Circuit in JTEC
RE transmissions.
P0756 AW4 Shift Sol B (2-3) Functional
FailureShift solenoid B (2-3) functional fault - Aisin
transmission
P0783 3-4 Shift Sol, No RPM Drop at
LockupThe overdrive solenoid is unable to engage the gear
change from 3rd gear to the overdrive gear.
P0801 Reverse Gear Lockout Circuit Open
or ShortAn open or shorted condition detected in the
transmission reverse gear lock-out solenoid control
circuit.
P01192 Inlet Air Temp. Circuit Low Inlet Air Temp. sensor input below acceptable voltage
P01193 Inlet Air Temp. Circuit High Inlet Air Temp. sensor input above acceptable voltage.
P1195 (M) 1/1 O2 Sensor Slow During Catalyst
MonitorA slow switching oxygen sensor has been detected in
bank 1/1 during catalyst monitor test. (was P0133)
P1196 (M) 2/1 O2 Sensor Slow During Catalyst
MonitorA slow switching oxygen sensor has been detected in
bank 2/1 during catalyst monitor test. (was P0153)
P1197 1/2 O2 Sensor Slow During Catalyst
MonitorA slow switching oxygen sensor has been detected in
bank 1/2 during catalyst monitor test. (was P0139)
P1198 Radiator Temperature Sensor Volts
Too HighRadiator coolant temperature sensor input above the
maximum acceptable voltage.
P1199 Radiator Temperature Sensor Volts
Too LowRadiator coolant temperature sensor input below the
minimum acceptable voltage.
P1281 Engine is Cold Too Long Engine coolant temperature remains below normal
operating temperatures during vehicle travel
(Thermostat).
P1282 Fuel Pump Relay Control Circuit An open or shorted condition detected in the fuel pump
relay control circuit.
P1288 Intake Manifold Short Runner
Solenoid CircuitAn open or shorted condition detected in the short
runner tuning valve circuit.
P1289 Manifold Tune Valve Solenoid
CircuitAn open or shorted condition detected in the manifold
tuning valve solenoid control circuit.
P1290 CNG Fuel System Pressure Too
HighCompressed natural gas system pressure above normal
operating range.
P1291 No Temp Rise Seen From Intake
HeatersEnergizing Heated Air Intake does not change intake air
temperature sensor an acceptable amount.
PLEMISSION CONTROL SYSTEMS 25 - 11
DESCRIPTION AND OPERATION (Continued)

MONITORED SYSTEMS
DESCRIPTION
There are new electronic circuit monitors that
check fuel, emission, engine and ignition perfor-
mance. These monitors use information from various
sensor circuits to indicate the overall operation of the
fuel, engine, ignition and emission systems and thus
the emissions performance of the vehicle.
The fuel, engine, ignition and emission systems
monitors do not indicate a specific component prob-
lem. They do indicate that there is an implied prob-
lem within one of the systems and that a specific
problem must be diagnosed.
If any of these monitors detect a problem affecting
vehicle emissions, the Malfunction Indicator (Check
Engine) Lamp will be illuminated. These monitors
generate Diagnostic Trouble Codes that can be dis-
played with the check engine lamp or a scan tool.
The following is a list of the monitored systems:
²EGR Monitor
²Misfire Monitor
²Fuel System Monitor
²Evaporative Emissions Monitor
Following is a description of each system monitor,
and its DTC.
Refer to the appropriate Powertrain Diagnos-
tics Procedures manual for diagnostic proce-
dures.
EGR MONITOR
The Powertrain Control Module (PCM) performs
an on-board diagnostic check of the EGR system.
The EGR system consists of two main components:
a vacuum solenoid back pressure transducer and a
vacuum operated valve. The EGR monitor is used to
test whether the EGR system is operating within
specifications. The diagnostic check activates only
during selected engine/driving conditions. When the
conditions are met, the EGR is turned off (solenoid
energized) and the O2S compensation control is mon-
itored. Turning off the EGR shifts the air fuel (A/F)
ratio in the lean direction. Oxygen sensor voltage
then indicates increased oxygen in the exhaust. Con-
sequently, Short Term Compensation shifts to rich
(increased injector pulse width). By monitoring the
shift, the PCM can indirectly monitor the EGR sys-
tem. While this test does not directly measure the
operation of the EGR system, it can be inferred from
the shift in the O2S data whether the EGR system is
operating correctly. Because the O2S is being used,
the O2S test must pass its test before the EGR test.
Enabling ConditionsÐ
²Engine Temperature
²Engine Run Time
²Engine RPM²MAP Sensor
²TPS
²Vehicle Speed
²Short Term Compensation
Pending ConditionsÐThe EGR Monitor does
not run when any of the following example faults
have illuminated the MIL:
²Misfire
²Oxygen Sensor Monitor
²Oxygen Sensor Heater Monitor
²Fuel System Rich/Lean
²Limp in for MAP, TPS or ECT
²Vehicle Speed Sensor
²Cam or Crank Sensor
²EGR Electrical
²EVAP Electrical
²Fuel Injector
²Ignition Coil
²Idle Speed
²Engine Coolant Temperature (ECT)
²MAP Sensor
²Intake Air Temperature (IAT)
Conflict ConditionsÐThe EGR Monitor typi-
cally does not run if any of the following conditions
are present:
²Fuel System Monitor
²Purge Monitor
²Catalyst Monitor
²Low Fuel Level
²High Altitude
²Low Ambient Air Temperature
The EGR Monitor does not run if any of the follow-
ing example DTCs are present:
²Misfire Monitor, Priority 2
²Upstream Oxygen Sensor Heater, Priority 1
²Fuel System Monitor, Priority 2
²Oxygen Sensor Monitor, Priority 1
MISFIRE MONITOR
Excessive engine misfire results in increased cata-
lyst temperature and causes an increase in HC emis-
sions. Severe misfires could cause catalyst damage.
To prevent catalytic convertor damage, the PCM
monitors engine misfire.
The Powertrain Control Module (PCM) monitors
for misfire during most engine operating conditions
(positive torque) by looking at changes in the crank-
shaft speed. If a misfire occurs the speed of the
crankshaft will vary more than normal.
OBD II regulations for misfire monitoring require
two different tests for misfire. The first is a Catalyst
Damage level of misfire test. The second is for emis-
sions greater than 1.5 times the Federal Tailpipe
(FTP) standards. The tests are monitored by two dif-
ferent counters. These counters are:
PLEMISSION CONTROL SYSTEMS 25 - 15
DESCRIPTION AND OPERATION (Continued)

²200 revolution increments for immediate cata-
lyst damage
²1000 revolution increments for emissions viola-
tion and Inspection/Maintenance (I/M) test failure
NOTE: The percent of misfire for malfunction crite-
ria varies due to RPM and load. As the engine
speed increases or load decreases, the effects of a
misfire diminishes due to crankshaft momentum.
Failure percentages also vary from engine to
engine.
Monitor OperationÐThe PCM utilizes the
Crankshaft Speed Fluctuation method to monitor for
misfire. The misfire monitor utilizes a crankshaft
position sensor to determine engine RPM. The sensor
can detect slight variations in engine speed due to
misfire. Misfire is continuously monitored once the
enabling conditions are met.
Once enabling conditions are met, the PCM counts
the number of misfires in every 200 revolutions of
the crankshaft. If, duringfive200 counters, the mis-
fire percentage exceeds a predetermined value, a
maturing code is set and a Freeze Frame is entered.
Freeze Frame data is recorded during the last 200
revolutions of the 1000 revolution period. A failure on
the second consecutive trip matures the code and a
DTC is set.
If misfire continues during the initial trip, the MIL
is not illuminated. However, the MIL flashes when
the misfire percentage exceeds the malfunction per-
centage, in any 200 revolution period, that would
cause permanent catalyst damage. This is a one trip
monitor. If misfire reaches a point in which catalyst
damage is likely to occur, the MIL flashes and a DTC
is stored in a Freeze Frame. The engine defaults to
open loop operation to prevent increased fuel flow to
the cylinders. Once misfire is below the predeter-
mined percentage, the MIL stops flashing but
remains illuminated.
The 1000 revolution counters are two trip moni-
tors. As with the fuel system monitor, Freeze Frame
data is from the original fault, and MIL extinguish-
ing requires the monitor to pass under similar condi-
tions.
The Adaptive NumeratorÐThe Misfire Monitor
takes into account component wear, sensor fatigue
and machining tolerances. The PCM compares the
crankshaft in the vehicle to data on an ideal crank
and uses this as a basis to determine variance. To do
this, the crankshaft sensor monitors the reference
notches in the crank. The PCM uses the first signal
set as a point of reference. It then measures where
the second set of signals is, compared to where engi-
neering data has determined it should be. This vari-
ance is the Adaptive Numerator. The monitor will not
run if the numerator is not set.If the Adaptive Numerator is equal to the default
value, the adaptive Numerator has not been learned
and the Misfire Monitor does not run. If the Adaptive
Numerator exceeds its limits, the PCM sets a DTC
for Adaptive Numerator and illuminates the MIL.
RPM ErrorÐThe PCM also checks the machining
tolerances for each group of slots. By monitoring the
speed of the crank from the first slot to the last slot
in a group, the PCM can calculate engine RPM. The
variance between groups of slots is know as the RPM
error. In order for the PCM to run the Misfire Mon-
itor, RPM error must be less than approximately 5%.
Enabling ConditionsÐThe following conditions
must be met before the PCM runs the Misfire Moni-
tor:
²RPM
²Engine Coolant Temperature (ECT)
²Barometric Pressure (MAP)
²Fuel level
²Ambient air Temperature
Pending ConditionsÐThe Misfire Monitor does
not run when the MIL is illuminated for any of the
following:
²Limp in mode for
Ð MAP
Ð TPS
Ð Crankshaft Sensor
Ð Engine Coolant Temperature Sensor
²Speed Sensor DTC
²EGR Electrical
²EVAP Electrical
²Idle Speed Faults
²Intake Air Temperature
²Oxygen Sensor Monitor
²Oxygen Sensor Electrical
Conflict ConditionsÐIf any of the following con-
ditions conflict with the Misfire Monitor, the monitor
will not run:
²Low fuel level
²MAP voltage rapidly changing
²Severe engine decel
²TPS toggling OPEN/CLOSED
²Engine RPM too low (RPM levels by vehicle)
²Engine RPM too high (RPM levels vary by vehi-
cle)
²Full Lean or Decel Fuel Shut-off
²Cold start
FUEL SYSTEM MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide. The catalyst works best
when the air fuel (A/F) ratio is at or near the opti-
mum of 14.7 to 1.
25 - 16 EMISSION CONTROL SYSTEMSPL
DESCRIPTION AND OPERATION (Continued)

The PCM is programmed to maintain the optimum
air/fuel ratio of 14.7 to 1. This is done by making
short term corrections in the fuel injector pulse width
based on the O2S output. The programmed memory
acts as a self calibration tool that the engine control-
ler uses to compensate for variations in engine spec-
ifications, sensor tolerances and engine fatigue over
the life span of the engine. By monitoring the actual
air-fuel ratio with the O2S (short term) and multiply-
ing that with the program long-term (adaptive) mem-
ory and comparing that to the limit, it can be
determined whether it will pass an emissions test. If
a malfunction occurs such that the PCM cannot
maintain the optimum A/F ratio, then the MIL will
be illuminated.
Monitor OperationÐFuel systems monitors do
not have a pre-test because they are continuously
running monitors. Therefore, the PCM constantly
monitors Short Term Compensation and Long Term
Adaptive memory.
Lean: If at anytime during a lean engine operation,
short term compensation multiplied by long term
adaptive exceeds a certain percentage for an
extended period, the PCM sets a Fuel System Lean
Fault for that trip and a Freeze Frame is entered.
Rich: If at anytime during a rich operation, Short
Term Compensation multiplied by Long Term Adap-
tive is less than a predetermined value, the PCM
checks the Purge Free Cells.
Purge Free Cells are values placed in Adaptive
Memory cells when the EVAP Purge Solenoid is OFF.
Two, three or four Purge Free cells are used. One cor-
responds to an Adaptive Memory cell at idle, the
other to a cell that is off-idle. For example, if a Purge
Free cell is labeled PFC1, it would hold the value for
Adaptive Memory cell C1 under non-purge condi-
tions.
If all Purge Free Cells are less than a certain per-
centage, and the Adaptive Memory factor is less than
a certain percentage, the PCM sets a Fuel System
Rich fault for that trip and a Freeze Frame is
entered.
The Fuel Monitor is a two trip monitor. The PCM
records engine data in Freeze Frame upon setting of
the first fault, or maturing code. When the fuel mon-
itor fails on a second consecutive trip, the code is
matured and the MIL is illuminated. The stored
Freeze Frame data is still from the first fault.
In order for the PCM to extinguish the MIL, the
Fuel Monitor must pass in a Similar Condition Win-
dow. The similar conditions relate to RPM and load.
The engine must be within a predetermined percent-
age of both RPM and load when the monitor runs to
count a good trip. As with all DTCs, three good tripsare required to extinguish the MIL and 40 warm up
cycles are required to erase the DTC. If the engine
does not run in a Similar Conditions Window, the
Task Manager extinguishes the MIL after 80 good
trips.
Enabling ConditionsÐThe following conditions
must be met to operate the fuel control monitor:
²PCM not in fuel crank mode (engine running)
²PCM in Closed Loop fuel control
²Fuel system updating Long Term Adaptive
²Fuel level above 15% of capacity
²Fuel level below 85% of capacity
Pending ConditionsÐThe Fuel Control Monitor
does not operate if the MIL is illuminated for any of
the following:
²Misfire Monitor
²Upstream O2S
²EVAP Purge Solenoid Electrical PCM Self Test
Fault
²Camshaft or Crankshaft Position Sensor
²Fuel Injectors
²Ignition Coil Primary
²Throttle Position (TPS) Sensor
²Engine Coolant Temperature (ECT) Sensor
²Manifold Absolute Pressure (MAP) Sensor
²Idle Air Control (IAC)
²5V Output Too Low
²EGR Monitor
²EGR Solenoid Circuit
²Vehicle Speed Sensor
²Oxygen Sensor Monitor
²Oxygen Sensor Heater Monitor
²Oxygen Sensor Electrical
²Idle Speed Rationality
²Intake Air Temperature
SuspendÐThe Task Manager will suspend
maturing a Fuel System fault if any of the following
are present:
²Oxygen Sensor Response, Priority 1
²O2 Heater, Priority 1
²Misfire Monitor, Priority 2
EVAPORATIVE EMISSIONS MONITOR
LEAK DETECTION PUMP MONITORÐThe
leak detection assembly incorporates two primary
functions: it must detect a leak in the evaporative
system and seal the evaporative system so the leak
detection test can be run.
The primary components within the assembly are:
A three port solenoid that activates both of the func-
tions listed above; a pump which contains a switch,
two check valves and a spring/diaphragm, a canister
vent valve (CVV) seal which contains a spring loaded
vent seal valve.
PLEMISSION CONTROL SYSTEMS 25 - 17
DESCRIPTION AND OPERATION (Continued)

when the MIL is illuminated due to any of the fol-
lowing faults:
²Misfire
²Oxygen Sensor Monitor
²Fuel System Rich
²Fuel System Lean
²EGR Monitor
²MAP
²TPS
²ECT
²DCP Solenoid
Conflict Conditions-With or Without LDPÐ
The EVAP Monitor does not run if any of the follow-
ing tests are in progress:
²Catalyst
²EGR
²Fuel System
²Misfire
TRIP DEFINITION
OPERATION
A ªTripº means vehicle operation (following an
engine-off period) of duration and driving mode such
that all components and systems are monitored at
least once by the diagnostic system. The monitors
must successfully pass before the PCM can verify
that a previously malfunctioning component is meet-
ing the normal operating conditions of that compo-
nent. For misfire or fuel system malfunction, the
MIL may be extinguished if the fault does not recur
when monitored during three subsequent sequential
driving cycles in which conditions are similar to
those under which the malfunction was first deter-
mined.
Anytime the MIL is illuminated, a DTC is stored.
The DTC can self erase only when the MIL has been
extinguished. Once the MIL is extinguished, the
PCM must pass the diagnostic test for the most
recent DTC for 40 warm-up cycles (80 warm-up
cycles for the Fuel System Monitor and the Misfire
Monitor). A warm-up cycle can best be described by
the following:
²The engine must be running
²A rise of 40ÉF in engine temperature must occur
from the time when the engine was started
²Engine coolant temperature must reach at least
160ÉF
²A ªdriving cycleº that consists of engine start up
and engine shut off.
Once the above conditions occur, the PCM is con-
sidered to have passed a warm-up cycle. Due to the
conditions required to extinguish the MIL and erase
the DTC, it is most important that after a repair has
been made, all DTC's be erased and the repair veri-
fied.
MONITORED COMPONENT
DESCRIPTION
There are several components that will affect vehi-
cle emissions if they malfunction. If one of these com-
ponents malfunctions the Malfunction Indicator
Lamp (Check Engine) will illuminate.
Some of the component monitors are checking for
proper operation of the part. Electrically operated
components now have input (rationality) and output
(functionality) checks. Previously, a component like
the Throttle Position sensor (TPS) was checked by
the PCM for an open or shorted circuit. If one of
these conditions occurred, a DTC was set. Now there
is a check to ensure that the component is working.
This is done by watching for a TPS indication of a
greater or lesser throttle opening than MAP and
engine rpm indicate. In the case of the TPS, if engine
vacuum is high and engine rpm is 1600 or greater
and the TPS indicates a large throttle opening, a
DTC will be set. The same applies to low vacuum
and 1600 rpm.
Any component that has an associated limp in will
set a fault after 1 trip with the malfunction present.
Refer to the Diagnostic Trouble Codes Description
Charts in this section and the appropriate Power-
train Diagnostic Procedure Manual for diagnostic
procedures.
The following is a list of the monitored compo-
nents:
²Comprehensive Components
²Oxygen Sensor Monitor
²Oxygen Sensor Heater Monitor
²Catalyst Monitor
COMPREHENSIVE COMPONENTS
Along with the major monitors, OBD II requires
that the diagnostic system monitor any component
that could affect emissions levels. In many cases,
these components were being tested under OBD I.
The OBD I requirements focused mainly on testing
emissions-related components for electrical opens and
shorts.
However, OBD II also requires that inputs from
powertrain components to the PCM be tested for
rationality, and that outputs to powertrain compo-
nents from the PCM be tested forfunctionality.
Methods for monitoring the various Comprehensive
Component monitoring include:
(1) Circuit Continuity
²Open
²Shorted high
²Shorted to ground
(2) Rationality or Proper Functioning
²Inputs tested for rationality
²Outputs tested for functionality
PLEMISSION CONTROL SYSTEMS 25 - 19
DESCRIPTION AND OPERATION (Continued)