fuel CHRYSLER VOYAGER 2004 Service Manual

EVAP/PURGE SOLENOID
DESCRIPTION
All vehicles use a proportional purge solenoid (Fig.
2). The solenoid regulates the rate of vapor flow from
the EVAP canister to the throttle body. The PCM
operates the solenoid.
OPERATION
During the cold start warm-up period and the hot
start time delay, the PCM does not energize the sole-
noid. When de-energized, no vapors are purged.
The proportional purge solenoid operates at a fre-
quency of 200 hz and is controlled by an engine con-
troller circuit that senses the current being applied
to the proportional purge solenoid and then adjusts
that current to achieve the desired purge flow. The
proportional purge solenoid controls the purge rate of
fuel vapors from the vapor canister and fuel tank to
the engine intake manifold.
REMOVAL
The solenoid attaches to a bracket near the radia-
tor on the passenger side of vehicle (Fig. 3). The sole-
noid will not operate unless it is installed correctly.
(1) Disconnect electrical connector from solenoid.
(2) Disconnect vacuum tubes from solenoid.
(3) Remove solenoid from bracket.
INSTALLATION
The solenoid attaches to a bracket near the radia-
tor on the passenger side of vehicle. The solenoid will
not operate unless it is installed correctly.The top of the solenoid has TOP printed on it. The
solenoid will not operate unless it is installed cor-
rectly.
(1) Install solenoid on bracket.
(2) Connect vacuum tube to solenoid.
(3) Connect electrical connector to solenoid.
FUEL FILLER CAP
DESCRIPTION
The plastic fuel fill cap is threaded/quarter turn
onto the end of the fuel filler tube. It's purpose is to
retain vapors and fuel in the fuel tank.
OPERATION
The fuel filler cap incorporates a two-way relief
valve that is closed to atmosphere during normal
operating conditions. The relief valve is calibrated to
open when a pressure of 17 kPa (2.5 psi) or vacuum
of 2 kPa (0.6 in. Hg) occurs in the fuel tank. When
the pressure or vacuum is relieved, the valve returns
to the normally closed position.
CAUTION: Remove the fuel filler cap to release fuel
tank pressure before disconnecting any fuel system
component.
Fig. 2 Proportional Purge Solenoid
Fig. 3 EVAP PURGE SOLENOID
1 - EVAP Purge Solenoid
2 - EGR VAlve
3 - Generator
25 - 12 EVAPORATIVE EMISSIONSRS

ORVR
OPERATION
The emission control principle used in the ORVR
system is that the fuel flowing into the filler tube
(appx. 1º I.D.) creates an aspiration effect which
draws air into the fill tube (Fig. 9). During refueling,
the fuel tank is vented to the vapor canister to cap-
ture escaping vapors. With air flowing into the filler
tube, there are no fuel vapors escaping to the atmo-
sphere. Once the refueling vapors are captured by
the canister, the vehicle's computer controlled purge
system draws vapor out of the canister for the engine
to burn. The vapors flow is metered by the purge
solenoid so that there is no or minimal impact on
driveability or tailpipe emissions.
As fuel starts to flow through the fill tube, it opens
the normally closed check valve and enters the fuel
tank. Vapor or air is expelled from the tank through
the control valve to the vapor canister. Vapor is
absorbed in the canister until vapor flow in the lines
stops, either following shut-off or by having the fuel
level in the tank rise high enough to close the control
valve. The control valve(Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/FUEL TANK - OPERATION)
contains a float that rises to seal the large diameter
vent path to the canister. At this point in the fueling
of the vehicle, the tank pressure increases, the check
valve closes (preventing tank fuel from spitting back
at the operator), and fuel then rises up the filler tube
to shut-off the dispensing nozzle.
If the engine is shut-off while the On-Board diag-
nostics test is running, low level tank pressure can
be trapped in the fuel tank and fuel can not be added
to the tank until the pressure is relieved. This is due
to the leak detection pump closing the vapor outlet
from the top of the tank and the one-way check valve
not allowing the tank to vent through the fill tube to
atmosphere. Therefore, when fuel is added, it will
back-up in the fill tube and shut off the dispensing
nozzle. The pressure can be eliminated in two ways:
1. Vehicle purge must be activated and for a long
enough period to eliminate the pressure. 2. Removing
the fuel cap and allowing enough time for the system
to vent thru the recirulation tube.
Fig. 7 LDP LOCATION
Fig. 8 LDP REMOVAL/INSTALLATION
25 - 14 EVAPORATIVE EMISSIONSRS
LEAK DETECTION PUMP (Continued)

Fig. 9 ORVR System Schematic
1 - FUEL TANK (PLASTIC)
2 - FUEL FILLER TUBE
3 - FUEL CAP (PRESSURE/RELIEF)
4 - FILL TUBE TO FUEL TANK CONNECTOR (ELASTOMERIC)
5 - TANK VENT/ROLLOVER VALVE(S)
6 - VAPOR RECIRCULATION LINE
7 - TANK VAPOR LINE
8 - VAPOR LINE TO CANISTER
9 - CHECK VALVE (N/C)
10 - CONTROL VALVE
11 - NATURAL VACUUM LEAD DETECTION (NVLD)12 - LIQUID SEPARATOR (IF EQUIPPED)
13 - ENGINE WIRING HARNESS TO NVLD
14 - VAPOR CANISTER
15 - PURGE LINE
16 - PURGE DEVICE
17 - WITHOUT NVLD
18 - BREATHER ELEMENT
19 - FLOW CONTROL ORIFICE
20 - SERVICE PORT
21 - WITH NVLD
RSEVAPORATIVE EMISSIONS25-15
ORVR (Continued)

DIAGNOSIS AND TESTING - VEHICLE DOES
NOT FILL
CONDITION POSSIBLE CAUSES CORRECTION
Pre-Mature Nozzle Shut-Off Defective fuel tank assembly
components.Fill tube improperly installed
(sump)
Fill tube hose pinched.
Check valve stuck shut.
Control valve stuck shut.
Defective vapor/vent components. Vent line from control valve to
canister pinched.
Vent line from canister to vent
filter pinched.
Canister vent valve failure
(requires double failure,
plugged to NVLD and
atmosphere).
Leak detection pump failed
closed.
Leak detection pump filter
plugged.
On-Board diagnostics evaporative
system leak test just conducted.Canister vent valve vent
plugged to atmosphere.
engine still running when
attempting to fill (System
designed not to fill).
Defective fill nozzle. Try another nozzle.
Fuel Spits Out Of Filler
Tube.During fill. See Pre-Mature Shut-Off.
At conclusion of fill. Defective fuel handling
component. (Check valve stuck
open).
Defective vapor/vent handling
component.
Defective fill nozzle.
PCV VALVE
DESCRIPTION
The PCV valve contains a spring loaded plunger.
The plunger meters the amount of crankcase vapors
routed into the combustion chamber based on intake
manifold vacuum (Fig. 10) or (Fig. 11).
OPERATION
When the engine is not operating or during an
engine backfire, the spring forces the plunger back
against the seat. This prevents vapors from flowing
through the valve (Fig. 12).When the engine is at idle or cruising, high mani-
fold vacuum is present. At these times manifold vac-
uum is able to completely compress the spring and
pull the plunger to the top of the valve (Fig. 13). In
this position there is minimal vapor flow through the
valve.
During periods of moderate intake manifold vac-
uum the plunger is only pulled part way back from
the inlet. This results in maximum vapor flow
through the valve (Fig. 14).
25 - 16 EVAPORATIVE EMISSIONSRS
ORVR (Continued)

VAPOR CANISTER
DESCRIPTION
There are 2 EVAP canisters on the vehicle. The
vacuum and vapor tubes connect to the top of the
canister. It is a charcoal canister (Fig. 15) or (Fig.
16).
OPERATION
All vehicles use a maintenance free, evaporative
(EVAP) canister. Fuel tank vapors vent into the can-
ister. The canister temporarily holds the fuel vapors
until intake manifold vacuum draws them into the
combustion chamber. The Powertrain Control Module
(PCM) purges the canister through the proportional
purge solenoid. The PCM purges the canister at pre-
determined intervals and engine conditions.
Purge Free Cells
Purge-free memory cells are used to identify the
fuel vapor content of the evaporative canister. Since
the evaporative canister is not purged 100% of the
time, the PCM stores information about the evapora-
tive canister's vapor content in a memory cell.
The purge-free cells are constructed similar to cer-
tain purge-normal cells. The purge-free cells can be
monitored by the DRB IIItScan Tool. The only dif-
ference between the purge-free cells and normal
adaptive cells is that in purge-free, the purge is com-
pletely turned off. This gives the PCM the ability to
compare purge and purge-free operation.
REMOVAL
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the 2 hoses (Fig. 15).
(3) Remove bolt.
(4) Pull canister rearward to remove.
Fig. 15 FRONT EVAP CANISTER
1 - Front EVAP Canister
2 - Vent Valve
Fig. 16 REAR EVAP CANISTER
1 - Rear EVAP Canister
2 - Front EVAP Canister
3 - Vent Valve
25 - 18 EVAPORATIVE EMISSIONSRS

VA LV E
DESCRIPTION
The EGR system consists of:
²EGR tube (connects a passage in the intake
manifold to the exhaust port in the cylinder head)
²EGR valve
²Electronic EGR Transducer
²Connecting hoses
OPERATION
Refer to Monitored Systems - EGR Monitor in this
group for more information.
The engines use Exhaust Gas Recirculation (EGR)
systems. The EGR system reduces oxides of nitrogen
(NOx) in engine exhaust and helps prevent detona-
tion (engine knock). Under normal operating condi-
tions, engine cylinder temperature can reach more
than 3000ÉF. Formation of NOx increases proportion-
ally with combustion temperature. To reduce the
emission of these oxides, the cylinder temperature
must be lowered. The system allows a predetermined
amount of hot exhaust gas to recirculate and dilute
the incoming air/fuel mixture. The diluted air/fuel
mixture reduces peak flame temperature during com-
bustion.
The electric EGR transducer contains an electri-
cally operated solenoid and a back-pressure trans-
ducer (Fig. 2). The Powertrain Control Module (PCM)
operates the solenoid. The PCM determines when toenergize the solenoid. Exhaust system back-pressure
controls the transducer.
When the PCM energizes the solenoid, vacuum
does not reach the transducer. Vacuum flows to the
transducer when the PCM de-energizes the solenoid.
When exhaust system back-pressure becomes high
enough, it fully closes a bleed valve in the trans-
ducer. When the PCM de-energizes the solenoid and
back-pressure closes the transducer bleed valve, vac-
uum flows through the transducer to operate the
EGR valve.
Fig. 1 EGR VALVE AND TUBE 2.4L
1 - EGR Tube
2 - EGR Valve
Fig. 2 EGR Valve and Transducer - Typical
1 - DIAPHRAGM
2 - PISTON
3 - SPRING
4 - EGR VALVE ASSEMBLY
5 - VACUUM MOTOR
6 - VACUUM MOTOR FITTING
7 - VACUUM OUTLET FITTING TO EGR VALVE
8 - EGR VALVE CONTROL ASSEMBLY
9 - ELECTRIC SOLENOID PORTION OF VALVE CONTROL
10 - VACUUM INLET FITTING FROM ENGINE
11 - BACK-PRESSURE HOSE
12 - TRANSDUCER PORTION OF VALVE CONTROL
13 - ELECTRICAL CONNECTION POINT
14 - EGR VALVE BACK-PRESSURE FITTING
15 - EXHAUST GAS INLET
16 - STEM PROTECTOR AND BUSHING
17 - BASE
18 - MOVEMENT INDICATOR
19 - POPPET VALVE
20 - SEAT
21 - EXHAUST GAS OUTLET
25 - 22 EXHAUST GAS RECIRCULATIONRS

ON-BOARD DIAGNOSTICS
TABLE OF CONTENTS
page page
TASK MANAGER
DESCRIPTION.........................24OPERATION...........................24
TASK MANAGER
DESCRIPTION
The PCM is responsible for efficiently coordinating
the operation of all the emissions-related compo-
nents. The PCM is also responsible for determining if
the diagnostic systems are operating properly. The
software designed to carry out these responsibilities
is call the ªTask Managerº.
OPERATION
The Task Manager determines when tests happen
and when functions occur. Many of the diagnostic
steps required by OBD II must be performed under
specific operating conditions. The Task Manager soft-
ware organizes and prioritizes the diagnostic proce-
dures. The job of the Task Manager is to determine if
conditions are appropriate for tests to be run, moni-
tor the parameters for a trip for each test, and record
the results of the test. Following are the responsibil-
ities of the Task Manager software:
²Test Sequence
²MIL Illumination
²Diagnostic Trouble Codes (DTCs)
²Trip Indicator
²Freeze Frame Data Storage
²Similar Conditions Window
Test Sequence
In many instances, emissions systems must fail
diagnostic tests more than once before the PCM illu-
minates the MIL. These tests are known as 'two trip
monitors.' Other tests that turn the MIL lamp on
after a single failure are known as 'one trip moni-
tors.' A trip is defined as 'start the vehicle and oper-
ate it to meet the criteria necessary to run the given
monitor.'
Many of the diagnostic tests must be performed
under certain operating conditions. However, there
are times when tests cannot be run because another
test is in progress (conflict), another test has failed
(pending) or the Task Manager has set a fault that
may cause a failure of the test (suspend).
²Pending
Under some situations the Task Manager will notrun a monitor if the MIL is illuminated and a fault is
stored from another monitor. In these situations, the
Task Manager postpones monitorspendingresolu-
tion of the original fault. The Task Manager does not
run the test until the problem is remedied.
For example, when the MIL is illuminated for an
Oxygen Sensor fault, the Task Manager does not run
the Catalyst Monitor until the Oxygen Sensor fault is
remedied. Since the Catalyst Monitor is based on sig-
nals from the Oxygen Sensor, running the test would
produce inaccurate results.
²Conflict
There are situations when the Task Manager does
not run a test if another monitor is in progress. In
these situations, the effects of another monitor run-
ning could result in an erroneous failure. If thiscon-
flictis present, the monitor is not run until the
conflicting condition passes. Most likely the monitor
will run later after the conflicting monitor has
passed.
For example, if the Fuel System Monitor is in
progress, the Task Manager does not run the catalyst
Monitor. Since both tests monitor changes in air/fuel
ratio and adaptive fuel compensation, the monitors
will conflict with each other.
²Suspend
Occasionally the Task Manager may not allow a two
trip fault to mature. The Task Manager willsus-
pendthe maturing of a fault if a condition exists
that may induce an erroneous failure. This prevents
illuminating the MIL for the wrong fault and allows
more precise diagnosis.
For example, if the PCM is storing a one trip fault
for the Oxygen Sensor and the catalyst monitor, the
Task Manager may still run the catalyst Monitor but
will suspend the results until the Oxygen Sensor
Monitor either passes or fails. At that point the Task
Manager can determine if the catalyst system is
actually failing or if an Oxygen Sensor is failing.
MIL Illumination
The PCM Task Manager carries out the illumina-
tion of the MIL. The Task Manager triggers MIL illu-
mination upon test failure, depending on monitor
failure criteria.
25 - 24 ON-BOARD DIAGNOSTICSRS

The Task Manager Screen shows both a Requested
MIL state and an Actual MIL state. When the MIL is
illuminated upon completion of a test for a good trip,
the Requested MIL state changes to OFF. However,
the MIL remains illuminated until the next key
cycle. (On some vehicles, the MIL will actually turn
OFF during the thirdgood trip) During the key cycle
for the third good trip, the Requested MIL state is
OFF, while the Actual MIL state is ON. After the
next key cycle, the MIL is not illuminated and both
MIL states read OFF.
Diagnostic Trouble Codes (DTCs)
With OBD II, different DTC faults have different
priorities according to regulations. As a result, the
priorities determine MIL illumination and DTC era-
sure. DTCs are entered according to individual prior-
ity. DTCs with a higher priority overwrite lower
priority DTCs.
Priorities
²Priority 0 ÐNon-emissions related trouble codes.
²Priority 1 Ð One trip failure of a two trip fault
for non-fuel system and non-misfire. (MIL Off)
²Priority 2 Ð One trip failure of a two trip fault
for fuel system (rich/lean) or misfire. (MIL Off)
²Priority3ÐTwotrip failure for a non-fuel sys-
tem and non-misfire or matured one trip comprehen-
sive component fault. (MIL On)
²Priority4ÐTwotrip failure or matured fault
for fuel system (rich/lean) and misfire or one trip cat-
alyst damaging misfire. Catalyst damage misfire is a
2 trip MIL. The MIL flashes on the first trip when
catalyst damage misfire levels are present. (MIL On)
Non-emissions related failures have no priority.
One trip failures of two trip faults have low priority.
Two trip failures or matured faults have higher pri-
ority. One and two trip failures of fuel system and
misfire monitor take precedence over non-fuel system
and non-misfire failures.
DTC Self Erasure
With one trip components or systems, the MIL is
illuminated upon test failure and DTCs are stored.
Two trip monitors are components requiring failure
in two consecutive trips for MIL illumination. Upon
failure of the first test, the Task Manager enters a
maturing code. If the component fails the test for a
second time the code matures and a DTC is set.
After three good trips the MIL is extinguished and
the Task Manager automatically switches the trip
counter to a warm-up cycle counter. DTCs are auto-
matically erased following 40 warm-up cycles if the
component does not fail again.
For misfire and fuel system monitors, the compo-
nent must pass the test under a Similar Conditions
Window in order to record a good trip. A Similar Con-ditions Window is when engine RPM is within  375
RPM and load is within  20% of when the fault
occurred.
NOTE: It is important to understand that a compo-
nent does not have to fail under a similar window of
operation to mature. It must pass the test under a
Similar Conditions Window when it failed to record
a Good Trip for DTC erasure for misfire and fuel
system monitors.
DTCs can be erased anytime with a DRBIIIt.
Erasing the DTC with the DRBIIIterases all OBD II
information. The DRBIIItautomatically displays a
warning that erasing the DTC will also erase all
OBD II monitor data. This includes all counter infor-
mation for warm-up cycles, trips and Freeze Frame.
Trip Indicator
TheTripis essential for running monitors and
extinguishing the MIL. In OBD II terms, a trip is a
set of vehicle operating conditions that must be met
for a specific monitor to run. All trips begin with a
key cycle.
Good Trip
The Good Trip counters are as follows:
²Global Good Trip
²Fuel System Good Trip
²Misfire Good Trip
²Alternate Good Trip (appears as a Global Good
Trip on DRBIIIt)
²Comprehensive Components
²Major Monitor
²Warm-Up Cycles
Global Good Trip
To increment a Global Good Trip, the Oxygen sen-
sor and Catalyst efficiency monitors must have run
and passed, and 2 minutes of engine run time.
Fuel System Good Trip
To count a good trip (three required) and turn off
the MIL, the following conditions must occur:
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
RSON-BOARD DIAGNOSTICS25-25
TASK MANAGER (Continued)

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, idle or driving
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
DRBIIIt. 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 two
trip faults. Freeze Frame data will only be overwrit-
ten by a different fault with a higher priority.
CAUTION: Erasing DTCs, either with the DRBIIIT;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 utilizes
both Short Term Compensation and Long Term Adap-
tive 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.
MISFIRE
²Same Misfire Warm-Up StateÐ Indicates if
the misfire occurred when the engine was warmed up
(above 160É F).
²In Similar Misfire WindowÐ An indicator
that 'Absolute MAP When Misfire Occurred' and
'RPM When Misfire Occurred' are all in the same
range when the failure occurred. Indicated by switch-
ing from 'NO' to 'YES'.
²Absolute MAP When Misfire OccurredÐ
The stored MAP reading at the time of failure.
Informs the user at what engine load the failure
occurred.
25 - 26 ON-BOARD DIAGNOSTICSRS
TASK MANAGER (Continued)

²Absolute MAPÐ A live reading of engine load
to aid the user in accessing the Similar Conditions
Window.
²RPM When Misfire OccurredÐ 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 utilizes
both Short Term Compensation and Long Term Adap-tive to calculate the Adaptive Memory Factor for
total fuel correction.
²200 Rev CounterÐ Counts 0±100 720 degree
cycles.
²SCW Cat 200 Rev CounterÐ Counts when in
similar conditions.
²SCW FTP 1000 Rev CounterÐ Counts 0±4
when in similar conditions.
²Misfire Good Trip CounterÐ Counts up to
three to turn OFF the MIL.
RSON-BOARD DIAGNOSTICS25-27
TASK MANAGER (Continued)