A R-134a refrigerant recovery/recycling/charging
station that meets SAE Standard J2210 must be
used to recover the refrigerant from an R-134a refrig-
erant system. Refer to the operating instructions sup-
plied by the equipment manufacturer for the proper
care and use of this equipment.
STANDARD PROCEDURE - REFRIGERANT
SYSTEM EVACUATE
NOTE: Special effort must be used to prevent mois-
ture from entering the A/C system oil. Moisture in
the oil is very difficult to remove and will cause a
reliability problem with the compressor.
If a compressor designed to use R-134a refrigerant
is left open to the atmosphere for an extended period
of time. It is recommended that the refrigerant oil be
drained and replaced with new oil or a new compres-
sor be used. This will eliminate the possibility of con-
taminating the refrigerant system.
If the refrigerant system has been open to the
atmosphere, it must be evacuated before the system
can be filled. Moisture and air mixed with the refrig-
erant will raise the compressor head pressure above
acceptable operating levels. This will reduce the per-
formance of the air conditioner and damage the com-
pressor. Moisture will boil at near room temperature
when exposed to vacuum. A R-134a refrigerant recov-
ery/recycling/charging station that meets SAE Stan-
dard J2210 must be used to evacuate the refrigerant
system. See the operating instructions supplied by
the equipment manufacturer for proper care and use
of this equipment. To evacuate the refrigerant sys-
tem, use the following procedure:
NOTE: When connecting the service equipment
couplings to the refrigerant system service ports,
be certain that the valve of each coupling is fully
closed. This will reduce the amount of effort
required to make the connection.
(1) Recover the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
(2) Connect a suitable charging station, refrigerant
recovery machine or a manifold gauge set with vac-
uum pump and refrigerant recovery equipment.
(3) Open the suction and discharge valves and
start the vacuum pump. The vacuum pump should
run a minimum of 45 minutes prior to charge to
eliminate all moisture in system. When the suction
gauge reads -88 kPa (-26 in. Hg) vacuum or greater
for 30 minutes, close all valves and turn off vacuum
pump. If the system fails to reach specified vacuum,
the refrigerant system likely has a leak that must be
corrected. If the refrigerant system maintains speci-fied vacuum for at least 30 minutes, start the vac-
uum pump, open the suction and discharge valves.
Then allow the system to evacuate an additional 10
minutes.
(4) Close all valves. Turn off and disconnect the
vacuum pump.
(5) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).STANDARD PROCEDURE - REFRIGERANT
SYSTEM CHARGE
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - WARNING - A/C PLUMBING) and (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - CAUTION - A/C PLUMBING).
After all refrigerant system leaks have been
repaired and the refrigerant system has been evacu-
ated, a refrigerant charge can be injected into the
system. For the proper amount of the refrigerant
charge, refer to REFRIGERANT CHARGE CAPAC-
ITY. A R-134a refrigerant recovery/recycling/charging
station that meets SAE Standard J2210 must be
used to charge the refrigerant system with R-134a
refrigerant. See the operating instructions supplied
by the equipment manufacturer for proper care and
use of this equipment.
REFRIGERANT CHARGE CAPACITY
The R-134a refrigerant system charge capacity for
this vehicle is:
²Single or Dual Zone (Front Unit Only - with
2.5L Turbo Diesel)0.79 kilograms (1.75 pounds or
28 ounces)
²Single or Dual Zone (Front Unit Only)- 0.88
kilograms (1.94 pounds or 31 ounces)
²Three Zone (Front and Rear Units)- 1.21
kilograms (2.69 pounds or 43 ounces)
NOTE: Always refer to the underhood HVAC Speci-
fication Tag for the latest fill specification for the
vehicle being serviced.
24 - 72 PLUMBING - FRONTRS
PLUMBING - FRONT (Continued)
CABIN HEATER
TABLE OF CONTENTS
page page
CABIN HEATER
DESCRIPTION........................112
OPERATION
OPERATION - MANUAL TEMPERATURE
CONTROL SYSTEM...................112
OPERATION - AUTOMATIC TEMPERATURE
CONTROL SYSTEM...................112
DIAGNOSIS AND TESTING - DIESEL
SUPPLEMENTAL CABIN HEATER........113
AIR INTAKE PIPE
REMOVAL............................113
INSTALLATION........................114
EXHAUST TUBE
REMOVAL............................114
INSTALLATION........................115FUEL DOSING PUMP
DESCRIPTION........................115
OPERATION..........................115
REMOVAL............................115
INSTALLATION........................116
FUEL LINE
STANDARD PROCEDURE - CLEANING.....117
REMOVAL............................117
INSTALLATION........................118
HEATER UNIT
REMOVAL............................118
INSTALLATION........................119
SUPPLEMENTAL DIESEL HEATER WIRING
REMOVAL............................119
INSTALLATION........................119
CABIN HEATER
DESCRIPTION
Vehicles equipped with the diesel engine are also
equipped with a supplemental cabin heater. This
cabin heater is mounted under the vehicle and oper-
ates similar to an oil fired furnace. The heater burns
small amounts of fuel to provide additional heat to
the coolant. Coolant is routed from the engine, to the
supplemental cabin heater and then to the front
heater core. This provides additional heat to the pas-
senger compartment. The supplemental cabin heater
system is interfaced to the vehicles on-board com-
puter systems and DRBIIItdiagnostics.
The supplemental cabin heater has an electronic
control module that monitors the heat output of the
heater. The cabin heater operates at full load (5 kW),
half load or idle mode (no additional heat) depending
on engine coolant temperature.
OPERATION
OPERATION - MANUAL TEMPERATURE
CONTROL SYSTEM
The supplemental cabin heater is activated via the
temperature slide control or knob on the A/C-heater
control when equipped with the manual temperature
control (MTC) system. If the slide control or knob is
moved to or above the upper set point the cabin
heater is activated. The cabin heater can operate in a
full or partial load range as well as an idle mode alldependent on the engine coolant temperature. The
cabin heater will also turn off if the A/C-heater tem-
perature control is lowered to less than the lower set
point. The cabin heater can take up to three minutes
to completely shut down when either the heater tem-
perature is set below the lower set point or the vehi-
cle ignition is shut down.
NOTE: Do not apply a strong vacuum source such
as a garage ventilation system directly on the sup-
plemental cabin heater exhaust line. Too strong of a
vacuum can prevent the supplemental cabin heater
from starting. If required, place the vacuum source
at least 75 mm (3 in.) away from the exhaust line.
The supplemental cabin heater only operates when
the engine is running, the mileage exceeds 8 kilome-
ter (5 mph) and the fuel tank volume exceeds 1/8 of a
tank. The supplemental heater control module moni-
tors blower speed and combustion during its start-up.
The cabin heater should operate if the coolant tem-
perature is below 40É C (104É F).
OPERATION - AUTOMATIC TEMPERATURE
CONTROL SYSTEM
The automatic temperature control (ATC) system
will activate the supplemental cabin heater based on
engine coolant temperature and interior component
settings. The cabin heater can operate in a full or
partial load range as well as an idle mode all depen-
dent on the engine coolant temperature. The cabin
heater will also turn off if the A/C-heater tempera-
ture control is lowered to less than the lower set
24 - 112 CABIN HEATERRS
point. The cabin heater can take up to three minutes
to completely shut down when either the heater tem-
perature is set below the lower set point or the vehi-
cle ignition is shut down.
NOTE: Do not apply a strong vacuum source such
as a garage ventilation system directly on the sup-
plemental cabin heater exhaust line. Too strong of a
vacuum can prevent the supplemental cabin heater
from starting. If required, place the vacuum source
at least 75 mm (3 in.) away from the exhaust line.
The supplemental cabin heater only operates when
the engine is running, the mileage exceeds 8 kilome-ter (5 mph) and the fuel tank volume exceeds 1/8 of a
tank. The supplemental heater control module moni-
tors blower speed and combustion during its start-up.
The cabin heater should operate if the coolant tem-
perature is below 40É C (104É F).
DIAGNOSIS AND TESTING - DIESEL
SUPPLEMENTAL CABIN HEATER
Refer to the Symptoms Diagnosis table for basic
checks of the diesel fueled supplemental cabin heater.
SYMPTOMS DIAGNOSIS
Symptom Possible Causes
Smell of diesel fuel. Check cabin heater system integration in vehicle's fuel system. Check
fuel lines for leakage, kinks or obstructions. If OK, Inspect the inlet
muffler, drain as necessary. Re-test the cabin heater and re-inspect.
Inspect the exhaust tube and cabin heater for the presence of external
fuel. If presence of external fuel is observed on the heater unit or in the
exhaust tube or after draining and testing. Remove the cabin heater
from vehicle and repair or replace components as required.
Heater does not achieve full load
operation.Check cabin heater operation with DRBIIITscan tool and replace
components as required.
Continuous white smoke from heater
exhaust during combustion operation.Check cabin heater operation with DRBIIITscan tool and replace
components as required. White smoke is typical in extreme weather
conditions.
Heater can not be switched off. Check cabin heater operation with DRBIIITscan tool and replace
components as required.
Heater does not operate. Diagnosis cabin heater control module using the DRBIIITscan tool and
the procedures listed in Vehicle Performance under Cabin Heater
Diagnosis in Group 18.
Loss of coolant (Leakage) or heater
develops smoke during combustion
operation and exhaust has an
extremely sweet smell.Inspect coolant hoses for leakage, kinks or loose hose connection.
Inspect the exhaust tube assembly for continuous flow, if OK there is an
internal heater leak and cabin heater should be inspected and
components should be replaced as required.
Loss of fuel (dripping). Check cabin heater system integration in vehicles fuel system. Check
fuel line connection for leakage. If OK there is an internal leak and
cabin heater should be inspected and replaced as required.
AIR INTAKE PIPE
REMOVAL
NOTE: The air intake tube for the supplemental
cabin heater is part of an assembly that includes
the heater cooling intake and return pipes. If the
cabin heater air intake tube requires removal or
replacement the entire cabin heater assembly will
require removal or replacement.(1) Drain the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(2) Remove clamps from the cabin heater tubes at
the lower heater port and the lower EGR connector
which are located under the hood.
(3) Remove the retaining clamp at the cabin
heater air intake muffler connection (Refer to 24 -
HEATING & AIR CONDITIONING/CABIN HEAT-
ER/INLET MUFFLER - REMOVAL).
(4) Remove the clamp at the flexible tube to steel
tube connection (Fig. 1).
RSCABIN HEATER24 - 113
CABIN HEATER (Continued)
EMISSIONS CONTROL
TABLE OF CONTENTS
page page
EMISSIONS CONTROL
DESCRIPTION
DESCRIPTION - VEHICLE EMISSION
CONTROL INFORMATION LABEL..........1
DESCRIPTION - TRIP DEFINITION.........1
DESCRIPTION - MONITORED COMPONENT . 1
OPERATION - NON-MONITORED CIRCUITS . . 5
DESCRIPTION - MONITORED SYSTEMS....6DESCRIPTION - HIGH AND LOW LIMITS....8
OPERATION
OPERATION - SYSTEM..................9
DRB IIITSTATE DISPLAY TEST MODE......9
EVAPORATIVE EMISSIONS................10
EXHAUST GAS RECIRCULATION...........21
ON-BOARD DIAGNOSTICS................24
EMISSIONS CONTROL
DESCRIPTION
DESCRIPTION - VEHICLE EMISSION CONTROL
INFORMATION LABEL
All models have a Vehicle Emission Control Infor-
mation (VECI) Label. Chrysler permanently attaches
the label in the engine compartment. It cannot be
removed without defacing information and destroying
the label.
The label contains the vehicle's emission specifica-
tions and vacuum hose routings. All hoses must be
connected and routed according to the label.
DESCRIPTION - TRIP DEFINITION
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 after 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 running²A rise of 40ÉF in engine temperature must occur
from the time when the engine was started
²Engine coolant temperature must crossover
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 by running 1±good trip.
DESCRIPTION - MONITORED COMPONENT
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 low and engine rpm is 1600 or greater and
the TPS indicates a small throttle opening, a DTC
will be set.
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 (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/POWERTRAIN CONTROL
MODULE - DESCRIPTION) and the appropriate
Powertrain Diagnostic Procedure Manual for diag-
nostic procedures.
RSEMISSIONS CONTROL25-1
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)