Vacuum CHRYSLER VOYAGER 2004 Service Manual

FUEL INJECTOR MECHANICAL MALFUNCTIONS
The PCM cannot determine if a fuel injector is
clogged, the needle is sticking or if the wrong injector
is installed. However, these could result in a rich or
lean condition causing the PCM to store a diagnostic
trouble code for either misfire, an oxygen sensor, or
the fuel system.
EXCESSIVE OIL CONSUMPTION
Although the PCM monitors engine exhaust oxygen
content when the system is in closed loop, it cannot
determine excessive oil consumption.
THROTTLE BODY AIR FLOW
The PCM cannot detect a clogged or restricted air
cleaner inlet or filter element.
VACUUM ASSIST
The PCM cannot detect leaks or restrictions in the
vacuum circuits of vacuum assisted engine control
system devices. However, these could cause the PCM
to store a MAP sensor diagnostic trouble code and
cause a high idle condition.
PCM SYSTEM GROUND
The PCM cannot determine a poor system ground.
However, one or more diagnostic trouble codes may
be generated as a result of this condition. The mod-
ule should be mounted to the body at all times,
including when diagnostics are performed.
PCM CONNECTOR ENGAGEMENT
The PCM may not be able to determine spread or
damaged connector pins. However, it might store
diagnostic trouble codes as a result of spread connec-
tor pins.
DESCRIPTION - MONITORED SYSTEMS
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 a DRBIIItscan tool.
The following is a list of the system monitors:
²EGR Monitor (if equipped)²Misfire Monitor
²Fuel System Monitor
²Oxygen Sensor Monitor
²Oxygen Sensor Heater Monitor
²Catalyst Monitor
²Evaporative System Leak Detection Monitor (if
equipped)
Following is a description of each system monitor,
and its DTC.
Refer to the appropriate Powertrain Diagnos-
tics Procedures manual for diagnostic proce-
dures.
OXYGEN SENSOR (O2S) MONITOR
Effective control of exhaust emissions is achieved
by an oxygen feedback system. The most important
element of the feedback system is the O2S. The O2S
is located in the exhaust path. Once it reaches oper-
ating temperatures of 300É to 350ÉC (572É to 662ÉF),
the sensor generates a voltage that is inversely pro-
portional to the amount of oxygen in the exhaust.
The information obtained by the sensor is used to
calculate the fuel injector pulse width. The PCM is
programmed to maintain the optimum air/fuel ratio.
At this mixture ratio, the catalyst works best to
remove hydrocarbons (HC), carbon monoxide (CO)
and nitrous oxide (NOx) from the exhaust.
The O2S is also the main sensing element for the
EGR (if equipped), Catalyst and Fuel Monitors.
The O2S may fail in any or all of the following
manners:
²Slow response rate
²Reduced output voltage
²Dynamic shift
²Shorted or open circuits
Response rate is the time required for the sensor to
switch from lean to rich once it is exposed to a richer
than optimum A/F mixture or vice versa. As the sen-
sor starts malfunctioning, it could take longer to
detect the changes in the oxygen content of the
exhaust gas.
The output voltage of the O2S ranges from 0 to 1
volt (voltages are offset by 2.5 volts on NGC vehi-
cles). A good sensor can easily generate any output
voltage in this range as it is exposed to different con-
centrations of oxygen. To detect a shift in the A/F
mixture (lean or rich), the output voltage has to
change beyond a threshold value. A malfunctioning
sensor could have difficulty changing beyond the
threshold value.
OXYGEN SENSOR HEATER MONITOR
If there is an oxygen sensor (O2S) DTC as well as
a O2S heater DTC, the O2S heater fault MUST be
repaired first. After the O2S fault is repaired, verify
that the heater circuit is operating correctly.
25 - 6 EMISSIONS CONTROLRS
EMISSIONS CONTROL (Continued)

chemical reaction takes place. This means the con-
centration of oxygen will be the same downstream as
upstream. The output voltage of the downstream
O2S copies the voltage of the upstream sensor. The
only difference is a time lag (seen by the PCM)
between the switching of the O2S's.
To monitor the system, the number of lean-to-rich
switches of upstream and downstream O2S's is
counted. The ratio of downstream switches to
upstream switches is used to determine whether the
catalyst is operating properly. An effective catalyst
will have fewer downstream switches than it has
upstream switches i.e., a ratio closer to zero. For a
totally ineffective catalyst, this ratio will be one-to-
one, indicating that no oxidation occurs in the device.
The system must be monitored so that when cata-
lyst efficiency deteriorates and exhaust emissions
increase to over the legal limit, the MIL (Check
Engine lamp) will be illuminated.
NATURAL VACUUM LEAK DETECTION (NVLD) (if equipped)
The Natural Vacuum Leak Detection (NVLD) sys-
tem is the next generation evaporative leak detection
system that will first be used on vehicles equipped
with the Next Generation Controller (NGC). This
new system replaces the leak detection pump as the
method of evaporative system leak detection. This is
to detect a leak equivalent to a 0.0209(0.5 mm) hole.
This system has the capability to detect holes of this
size very dependably.
The basic leak detection theory employed with
NVLD is the9Gas Law9. This is to say that the pres-
sure in a sealed vessel will change if the temperature
of the gas in the vessel changes. The vessel will only
see this effect if it is indeed sealed. Even small leaks
will allow the pressure in the vessel to come to equi-
librium with the ambient pressure. In addition to the
detection of very small leaks, this system has the
capability of detecting medium as well as large evap-
orative system leaks.
The NVLD seals the canister vent during engine off
conditions. If the EVAP system has a leak of less than
the failure threshold, the evaporative system will be
pulled into a vacuum, either due to the cool down
from operating temperature or diurnal ambient tem-
perature cycling. The diurnal effect is considered one
of the primary contributors to the leak determination
by this diagnostic. When the vacuum in the system
exceeds about 19H2O (0.25 KPA), a vacuum switch
closes. The switch closure sends a signal to the NGC.
The NGC, via appropriate logic strategies (described
below), utilizes the switch signal, or lack thereof, to
make a determination of whether a leak is present.
The NVLD device is designed with a normally open
vacuum switch, a normally closed solenoid, and a
seal, which is actuated by both the solenoid and a
diaphragm. The NVLD is located on the atmosphericvent side of the canister. The NVLD assembly may
be mounted on top of the canister outlet, or in-line
between the canister and atmospheric vent filter. The
normally open vacuum switch will close with about 19
H2O (0.25 KPA) vacuum in the evaporative system.
The diaphragm actuates the switch. This is above the
opening point of the fuel inlet check valve in the fill
tube so cap off leaks can be detected. Submerged fill
systems must have recirculation lines that do not
have the in-line normally closed check valve that pro-
tects the system from failed nozzle liquid ingestion,
in order to detect cap off conditions.
The normally closed valve in the NVLD is intended
to maintain the seal on the evaporative system dur-
ing the engine off condition. If vacuum in the evapo-
rative system exceeds 39to 69H2O (0.75 to 1.5 KPA),
the valve will be pulled off the seat, opening the seal.
This will protect the system from excessive vacuum
as well as allowing sufficient purge flow in the event
that the solenoid was to become inoperative.
The solenoid actuates the valve to unseal the can-
ister vent while the engine is running. It also will be
used to close the vent during the medium and large
leak tests and during the purge flow check. This sole-
noid requires initial 1.5 amps of current to pull the
valve open but after 100 ms. will be duty cycled down
to an average of about 150 mA for the remainder of
the drive cycle.
Another feature in the device is a diaphragm that
will open the seal in the NVLD with pressure in the
evaporative system. The device will9blow off9at
about 0.59H2O (0.12 KPA) pressure to permit the
venting of vapors during refueling. An added benefit
to this is that it will also allow the tank to9breathe9
during increasing temperatures, thus limiting the
pressure in the tank to this low level. This is benefi-
cial because the induced vacuum during a subse-
quent declining temperature will achieve the switch
closed (pass threshold) sooner than if the tank had to
decay from a built up pressure.
The device itself has 3 wires: Switch sense, sole-
noid driver and ground. It also includes a resistor to
protect the switch from a short to battery or a short
to ground. The NGC utilizes a high-side driver to
energize and duty-cycle the solenoid.
DESCRIPTION - HIGH AND LOW LIMITS
The PCM compares input signal voltages from each
input device with established high and low limits for
the device. If the input voltage is not within limits
and other criteria are met, the PCM stores a diagnos-
tic trouble code in memory. Other diagnostic trouble
code criteria might include engine RPM limits or
input voltages from other sensors or switches that
must be present before verifying a diagnostic trouble
code condition.
25 - 8 EMISSIONS CONTROLRS
EMISSIONS CONTROL (Continued)

EVAPORATIVE EMISSIONS
TABLE OF CONTENTS
page page
EVAPORATIVE EMISSIONS
OPERATION - EVAPORATION CONTROL
SYSTEM............................10
SPECIFICATIONS
TORQUE............................11
EVAP/PURGE SOLENOID
DESCRIPTION.........................12
OPERATION...........................12
REMOVAL.............................12
INSTALLATION.........................12
FUEL FILLER CAP
DESCRIPTION.........................12
OPERATION...........................12
NATURAL VAC LEAK DETECTION ASSY
REMOVAL.............................13
INSTALLATION.........................13
LEAK DETECTION PUMP
REMOVAL.............................13
INSTALLATION.........................13ORVR
OPERATION...........................14
DIAGNOSIS AND TESTING - VEHICLE DOES
NOT FILL............................16
P C V VA LV E
DESCRIPTION.........................16
OPERATION...........................16
DIAGNOSIS AND TESTING - PCV SYSTEM . . . 17
VAPOR CANISTER
DESCRIPTION.........................18
OPERATION...........................18
REMOVAL
REMOVAL...........................18
REMOVAL - WITH NVLD................19
REMOVAL - REAR EVAP CANISTER.......19
INSTALLATION
INSTALLATION.......................19
INSTALLATION - WITH NVLD............20
INSTALLATION - REAR EVAP CANISTER . . . 20
EVAPORATIVE EMISSIONS
OPERATION - EVAPORATION CONTROL
SYSTEM
The evaporation control system prevents the emis-
sion of fuel tank vapors into the atmosphere. When
fuel evaporates in the fuel tank, the vapors pass
through vent hoses or tubes to an activated carbon
filled evaporative canister. The canister temporarily
holds the vapors. The Powertrain Control Module
(PCM) allows intake manifold vacuum to draw
vapors into the combustion chambers during certain
operating conditions (Fig. 1).All engines use a proportional purge solenoid sys-
tem. The PCM controls vapor flow by operating the
purge solenoid. Refer to Proportional Purge Solenoid
in this section.
NOTE: The evaporative system uses specially man-
ufactured hoses. If they need replacement, only use
fuel resistant hose. Also the hoses must be able to
pass an Ozone compliance test.
NOTE: For more information on Onboard Refueling
Vapor Recovery (ORVR), refer to the Fuel Delivery
section.
25 - 10 EVAPORATIVE EMISSIONSRS

SPECIFICATIONS
TORQUE
DESCRIPTION N´m Ft. Lbs. In. Lbs.
PCV VAlve 3.3/3.8L 6.3 55
Fig. 1 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 EMISSIONS25-11
EVAPORATIVE EMISSIONS (Continued)

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

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)

DIAGNOSIS AND TESTING - PCV SYSTEM
WARNING: APPLY PARKING BRAKE AND/OR
BLOCK WHEELS BEFORE PERFORMING ANY TEST
OR ADJUSTMENT WITH THE ENGINE OPERATING.
(1) With engine idling, remove the hose from the
PCV valve. If the valve is not plugged, a hissing
noise will be heard as air passes through the valve. A
strong vacuum should also be felt when a finger is
placed over the valve inlet.
(2) Install hose on PCV valve. Remove the
make-up air hose from the air plenum at the rear of
the engine. Hold a piece of stiff paper (parts tag)
loosely over the end of the make-up air hose.
(3) After allowing approximately one minute for
crankcase pressure to reduce, the paper should draw
up against the hose with noticeable force. If the
engine does not draw the paper against the grommet
after installing a new valve, replace the PCV valve
hose.
(4) Turn the engine off. Remove the PCV valve
from intake manifold. The valve should rattle when
shaken.
(5) Replace the PCV valve and retest the system if
it does not operate as described in the preceding
tests.Do not attempt to clean the old PCV valve.
If the valve rattles, apply a light coating of Loctitet
Pipe Sealant With Teflon to the threads. Thread the
PCV valve into the manifold plenum and tighten to 7
N´m (60 in. lbs.) torque.
Fig. 10 PCV VALVE 2.4L
1 - PCV Valve
Fig. 11 PCV VALVE 3.3/3.8L
Fig. 12 Engine Off or Engine Backfire No Vapor
Flow
Fig. 13 High Intake Manifold Vacuum Minimal Vapor
Flow
Fig. 14 Moderate Intake Manifold Vacuum Maximum
Vapor Flow
RSEVAPORATIVE EMISSIONS25-17
PCV VALVE (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