2003 DODGE RAM ECU

STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE)
(7) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
LIQUID LINE
REMOVAL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
(1) Disconnect and isolate the battery negative
cable.
NOTE: Removal of the second battery and battery
tray is required on the diesel equipped vehicles.
(2) Remove rightside battery(Refer to 8 - ELEC-
TRICAL/BATTERY SYSTEM/BATTERY - REMOV-
AL).
(3) Remove rightside battery tray(Refer to 8 -
ELECTRICAL/BATTERY SYSTEM/TRAY - REMOV-
AL).
(4) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY)
(5) Disconnect the liquid line refrigerant line cou-
plers at the condenser outlet the mid point connec-
tion and the evaporator inlet. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - A/C LINE COUPLERS)
Install plugs in, or tape over all of the opened refrig-
erant line fittings.
(6) Disengage any clips that secure the liquid line
to the inner fender shield or cross brace. (Fig. 11).
(7) Remove the both sections of the liquid line
from the vehicle.
INSTALLATION
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)(Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -CAUTION - REFRIGERANT HOSES/LINES/TUBES
PRECAUTIONS)
(1) Install both sections of the liquid line into any
clips on the inner fender shield and the dash panel.
(2) Remove the tape or plugs from the refrigerant
line fittings on the liquid line, the condenser outlet,
and the evaporator inlet. Connect the liquid line
pieces together and to the condenser and the evapo-
rator. (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE - A/C
LINE COUPLERS)
NOTE: Installation of the second battery and battery
tray is required on the diesel equipped vehicles.
(3) Install the rightside battery tray(Refer to 8 -
ELECTRICAL/BATTERY SYSTEM/TRAY - INSTAL-
LATION).
(4) Install the rightside battery(Refer to 8 - ELEC-
TRICAL/BATTERY SYSTEM/BATTERY - INSTAL-
LATION).
(5) Connect the battery positive cables.
(6) Connect the battery negative cables.
(7) Evacuate the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
Fig. 11 A/C Liquid Line - Gas Engine shown
1 - A/C Line Retainer Clip
2 - A/C Line Retention Clip
3 - A/C Line Retainer Clip
4 - Liquid Line to Evaporator
5 - A/C Line Retention Clip
6 - Evaporator Ports
7 - A/C Condensor Modular
8 - A/C Jumper Line Retainer Nut
9 - A/C Line Retainer Clip
10 - A/C Liquid Jumper Line
DRPLUMBING 24 - 45
A/C DISCHARGE LINE (Continued)

STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE)
(8) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
SUCTION LINE
REMOVAL
REMOVAL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
(1) Disconnect and isolate the battery negative
cable.
(2) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY)
(3) Unplug the wire harness connector from the a/c
high pressure transducer.
(4) Disconnect the suction line refrigerant line cou-
pler at the accumulator. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - STANDARD
PROCEDURE - A/C LINE COUPLER) Install plugs
in, or tape over all of the opened refrigerant line fit-
tings.
(5) Remove the nut that secures the condenser
inlet and disconnect the discharge line from the con-
denser. Install plugs in, or tape over all of the opened
refrigerant line fittings.
(6) Remove the suction and discharge line assem-
bly from the vehicle.
REMOVAL - 5.9L DIESEL ENGINE
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
(1) Disconnect and isolate the battery negative
cable.
(2) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY)
(3) Unplug the wire harness connector from the a/c
high pressure switch.
(4) Disconnect the suction line refrigerant line cou-
pler at the accumulator. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - STANDARD
PROCEDURE - A/C LINE COUPLER) Install plugs
in, or tape over all of the opened refrigerant line fit-
tings.
(5) Remove the nut that secures the block fitting
to the stud on the condenser inlet and disconnect the
discharge line from the condenser. Install plugs in, or
tape over all of the opened refrigerant line fittings.
(6) Remove the bolt that secures the refrigerant
line manifold to the compressor (Fig. 12). Install
plugs in, or tape over all of the opened refrigerant
line fittings.
(7) Remove the suction and discharge line assem-
bly from the vehicle.
INSTALLATION
INSTALLATION
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)(Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTION - REFRIGERANT HOSES/LINES/TUBES
PRECAUTIONS)
Fig. 12 SUCTION AND DISCHARGE LINE REMOVE/
INSTALL - DIESEL ENGINE
1 - DISCHARGE LINE (TO CONDENSER)
2 - COMPRESSOR
3 - BOLT
4 - MANIFOLD
5 - SUCTION LINE (FROM ACCUMULATOR)
6 - A/C HIGH PRESSURE SWITCH
24 - 46 PLUMBINGDR
LIQUID LINE (Continued)

compartment. The liquid line should be hot to the
touch.
(5) Touch the liquid line near the evaporator inlet
at the rear of the engine compartment. The liquid
line should be cold to the touch.
(6) If there is a distinct temperature differential
between the two ends of the liquid line, the orifice
tube is in good condition. If there is little or no
detectable temperature differential between the two
ends of the liquid line, the orifice tube is obstructed
or missing and the liquid line must be replaced.
REMOVAL
The fixed orifice tube is located in the liquid line,
between the condenser and the evaporator coil. The
orifice has filter screens on the inlet and outlet ends
of the tube body. If the fixed orifice tube is faulty or
plugged, the liquid line assembly must be replace-
d(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/LIQUID LINE - REMOVAL).
INSTALLATION
The fixed orifice tube is located in the liquid line,
between the condenser and the evaporator coil. The
orifice has filter screens on the inlet and outlet ends
of the tube body. If the fixed orifice tube is faulty or
plugged, the liquid line assembly must be replace-
d(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/LIQUID LINE - INSTALLATION).
ACCUMULATOR
DESCRIPTION
The accumulator is mounted in the engine com-
partment between the A/C evaporator outlet tube and
the compressor inlet.
OPERATION
Refrigerant enters the accumulator canister as a
low pressure vapor through the inlet tube. Any liq-
uid, oil-laden refrigerant falls to the bottom of the
canister, which acts as a separator. A desiccant bag is
mounted inside the accumulator canister to absorb
any moisture which may have entered and become
trapped within the refrigerant system.
REMOVAL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)(1) Disconnect and isolate the battery negative
cable.
(2) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY)
(3) Loosen the fasteners that secure the accumula-
tor and support bracket to the dash panel (Fig. 15).
(4) Disconnect the suction line refrigerant line fit-
ting from the accumulator outlet. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - A/C LINE COUPLERS)
Install plugs in, or tape over all of the opened refrig-
erant line fittings.
(5) Disconnect the accumulator inlet refrigerant
line fitting from the evaporator outlet. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE) Install plugs in, or tape
over all of the opened refrigerant line fittings.
(6) Remove the accumulator assembly from the
engine compartment.
Fig. 15 A/C Accumulator
1 - Inner Fender
2 - Line from Accumulator to Evaporator
3 - A/C Line Rentention Clip
4 - Evaporator Ports
5 - Accumulator Mounting Screws
6 - Accumulator
7 - Suction Line
8 - A/C Charging Port
9 - A/C Line Rentention Clip
DRPLUMBING 24 - 49
A/C ORIFICE TUBE (Continued)

INSTALLATION
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)(Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTION - REFRIGERANT HOSES/LINES/TUBES
PRECAUTIONS)
(1) Install the accumulator to the bulkhead but do
not tighten yet.
(2) Remove the tape or plugs from the refrigerant
line fittings on the accumulator inlet and the evapo-
rator outlet. Connect the accumulator inlet refriger-
ant line coupler to the evaporator outlet. (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - A/C LINE COUPLERS)
(3) Remove the tape or plugs from the refrigerant
line fittings on the suction line and the accumulator
outlet. Connect the suction line refrigerant line cou-
pler to the accumulator outlet. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - A/C LINE COUPLERS)
(4) Tighten the accumulator fasteners to 4.5 N´m
(40 in. lbs.).
(5) Connect the battery negative cable.
(6) Evacuate the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE)
(7) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
NOTE: If the accumulator is replaced, add 60 milli-
liters (2 fluid ounces) of refrigerant oil to the refrig-
erant system. Use only refrigerant oil of the type
recommended for the compressor in the vehicle.
HEATER CORE
DESCRIPTION
The heater core is located in the HVAC housing,
under the instrument panel. It is a heat exchanger
made of rows of tubes and fins.
The heater core is not repairable and if damaged it
must be replaced.
OPERATION
Engine coolant is circulated through heater hoses
to the heater core at all times. As the coolant flowsthrough the heater core, heat removed from the
engine is transferred to the heater core fins and
tubes. Air directed through the heater core picks up
the heat from the heater core fins. The blend door
allows control of the heater output air temperature
by controlling how much of the air flowing through
the HVAC housing is directed through the heater
core. The blower motor speed controls the volume of
air flowing through the HVAC housing.
The heater core cannot be repaired and, if faulty or
damaged, it must be replaced.
REMOVAL
NOTE: Disassembly of the HVAC housing is not
required to remove heater core.
(1) Remove the HVAC housing from the vehicle.
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL)
(2) Remove the screws and retainers that secure
the heater core to the HVAC housing.
(3) Lift the heater core out of the heater-A/C hous-
ing.
(4) Inspect all seals and repair or replace as
required.
INSTALLATION
(1) Place the heater core into the HVAC housing.
(2) Snap the retainers for the heater core to the
housing. Install and tighten the screws that secure
the heater core to the HVAC housing (if equipped).
Tighten the screws to 2.2 N´m (20 in. lbs.).
(3) Reinstall the HVAC housing in the vehicle.
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - INSTALLA-
TION)
REFRIGERANT
DESCRIPTION
The refrigerant used in this air conditioning sys-
tem is a HydroFluoroCarbon (HFC), type R-134a.
Unlike R-12, which is a ChloroFluoroCarbon (CFC),
R-134a refrigerant does not contain ozone-depleting
chlorine. R-134a refrigerant is a non-toxic, non-flam-
mable, clear, and colorless liquefied gas.
Even though R-134a does not contain chlorine, it
must be reclaimed and recycled just like CFC-type
refrigerants. This is because R-134a is a greenhouse
gas and can contribute to global warming.
OPERATION
R-134a refrigerant is not compatible with R-12
refrigerant in an air conditioning system. Even a
24 - 50 PLUMBINGDR
ACCUMULATOR (Continued)

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 Lamp
(MIL) will be illuminated. These monitors generate
Diagnostic Trouble Codes that can be displayed with
the MIL or a scan tool.
The following is a list of the system monitors:
²Misfire Monitor
²Fuel System Monitor
²Oxygen Sensor Monitor
²Oxygen Sensor Heater Monitor
²Catalyst Monitor
²Leak Detection Pump Monitor (if equipped)
All these system monitors require two consecutive
trips with the malfunction present to set a fault.
Refer to the appropriate Powertrain Diagnos-
tics Procedures manual for diagnostic proce-
dures.
The following is an operation and description of
each system monitor :
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 temperature 300É to 350ÉC (572É to 662ÉF), the
sensor generates a voltage that is inversely propor-
tional to the amount of oxygen in the exhaust. The
information obtained by the sensor is used to calcu-
late the fuel injector pulse width. This maintains a
14.7 to 1 Air Fuel (A/F) ratio. At this mixture ratio,
the catalyst works best to remove hydrocarbons (HC),
carbon monoxide (CO) and nitrogen oxide (NOx) from
the exhaust.
The O2S is also the main sensing element for the
Catalyst and Fuel Monitors.
The O2S can 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 todetect the changes in the oxygen content of the
exhaust gas.
The output voltage of the O2S ranges from 0 to 1
volt. 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) shorted to volt-
age DTC, as well as a O2S heater DTC, the O2S
fault MUST be repaired first. Before checking the
O2S fault, verify that the heater circuit is operating
correctly.
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 temperature 300É to 350ÉC (572 É to 662ÉF), the
sensor generates a voltage that is inversely propor-
tional to the amount of oxygen in the exhaust. The
information obtained by the sensor is used to calcu-
late the fuel injector pulse width. This maintains a
14.7 to 1 Air Fuel (A/F) ratio. At this mixture ratio,
the catalyst works best to remove hydrocarbons (HC),
carbon monoxide (CO) and nitrogen oxide (NOx) from
the exhaust.
The voltage readings taken from the O2S sensor
are very temperature sensitive. The readings are not
accurate below 300ÉC. Heating of the O2S sensor is
done to allow the engine controller to shift to closed
loop control as soon as possible. The heating element
used to heat the O2S sensor must be tested to ensure
that it is heating the sensor properly.
The O2S sensor circuit is monitored for a drop in
voltage. The sensor output is used to test the heater
by isolating the effect of the heater element on the
O2S sensor output voltage from the other effects.
LEAK DETECTION PUMP MONITOR (IF EQUIPPED)
The leak detection assembly incorporates two pri-
mary functions: it must detect a leak in the evapora-
tive 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.
Immediately after a cold start, between predeter-
mined temperature thresholds limits, the three port
solenoid is briefly energized. This initializes the
25 - 2 EMISSIONS CONTROLDR
EMISSIONS CONTROL (Continued)

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 EGR
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 precis diagnosis.
For example, if the PCM is storing a one trip fault
for the Oxygen Sensor and the EGR monitor, the
Task Manager may still run the EGR 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 EGR system is actu-
ally 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.
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 third 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 third key cycle) During the key cycle
for the third good trip, the Requested MIL state is
OFF, while the Actual MILL 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.²Priority 2 Ð One trip failure of a two trip fault
for fuel system (rich/lean) or misfire.
²Priority3ÐTwotrip failure for a non-fuel sys-
tem and non-misfire or matured one trip comprehen-
sive component fault.
²Priority4ÐTwotrip failure or matured fault
for fuel system (rich/lean) and misfire or one trip cat-
alyst damaging misfire.
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  10% 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 DRB III. Eras-
ing the DTC with the DRB III erases all OBD II
information. The DRB III automatically 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:
25 - 6 EMISSIONS CONTROLDR
EMISSIONS CONTROL (Continued)

REMOVAL
The duty cycle EVAP canister purge solenoid is
located in the engine compartment. It is attached to
the side of the Power Distribution Center (PDC) (Fig.
3).
(1) Disconnect electrical wiring connector at sole-
noid.
(2) Disconnect vacuum harness at solenoid (Fig. 3).
(3) Remove solenoid from mounting bracket.
INSTALLATION
(1) Install solenoid assembly to mounting bracket.
(2) Connect vacuum harness.
(3) Connect electrical connector.
FUEL FILLER CAP
DESCRIPTION
The plastic fuel tank filler tube cap is threaded
onto the end of the fuel fill tube. Certain models are
equipped with a 1/4 turn cap.
OPERATION
The loss of any fuel or vapor out of fuel filler tube
is prevented by the use of a pressure-vacuum fuel fill
cap. Relief valves inside the cap will release fuel tank
pressure at predetermined pressures. Fuel tank vac-
uum will also be released at predetermined values.This cap must be replaced by a similar unit if
replacement is necessary. This is in order for the sys-
tem to remain effective.
CAUTION: Remove fill cap before servicing any fuel
system component to relieve tank pressure. If
equipped with a Leak Detection Pump (LDP), or
NVLD system, the cap must be tightened securely.
If cap is left loose, a Diagnostic Trouble Code (DTC)
may be set.
REMOVAL
REMOVAL/INSTALLATION
If replacement of the 1/4 turn fuel tank filler tube
cap is necessary, it must be replaced with an identi-
cal cap to be sure of correct system operation.
CAUTION: Remove the fuel tank filler tube cap to
relieve fuel tank pressure. The cap must be
removed prior to disconnecting any fuel system
component or before draining the fuel tank.
LEAK DETECTION PUMP
DESCRIPTION
Vehicles equipped with JTEC engine control mod-
ules use a leak detection pump. Vehicles equipped
with NGC engine control modules use an NVLD
pump. Refer to Natural Vacuum - Leak Detection
(NVLD) for additional information.
The evaporative emission system is designed to
prevent the escape of fuel vapors from the fuel sys-
tem (Fig. 4). Leaks in the system, even small ones,
can allow fuel vapors to escape into the atmosphere.
Government regulations require onboard testing to
make sure that the evaporative (EVAP) system is
functioning properly. The leak detection system tests
for EVAP system leaks and blockage. It also performs
self-diagnostics. During self-diagnostics, the Power-
train Control Module (PCM) first checks the Leak
Detection Pump (LDP) for electrical and mechanical
faults. If the first checks pass, the PCM then uses
the LDP to seal the vent valve and pump air into the
system to pressurize it. If a leak is present, the PCM
will continue pumping the LDP to replace the air
that leaks out. The PCM determines the size of the
leak based on how fast/long it must pump the LDP
as it tries to maintain pressure in the system.
Fig. 3 EVAP / DUTY CYCLE PURGE SOLENOID
1 - MOUNTING BRACKET
2 - VACUUM HARNESS
3 - DUTY CYCLE SOLENOID
4 - TEST PORT CAP AND TEST PORT
DREVAPORATIVE EMISSIONS 25 - 13
EVAP/PURGE SOLENOID (Continued)

HIGH-PRESSURE FUEL LINE LEAKS -
DIAGNOSIS AND TESTING.............14-69
HINGE - INSTALLATION.....23-16,23-22,23-31,
23-46
HINGE - INSTALLATION, CENTER SEAT
BACK..............................23-80
HINGE - REMOVAL....23-16,23-22,23-31,23-46
HINGE - REMOVAL, CENTER SEAT BACK . . 23-79
HINGE COVER - INSTALLATION, CENTER
SEAT BACK INERTIA..................23-78
HINGE COVER - REMOVAL, CENTER
SEAT BACK INERTIA..................23-78
HITCH - INSTALLATION, TRAILER........13-25
HITCH - REMOVAL, TRAILER...........13-25
HOAT COOLANT - DESCRIPTION..........7-37
HOISTING - STANDARD PROCEDURE......0-14
HOLDDOWN - DESCRIPTION, BATTERY . . . 8F-14
HOLDDOWN - INSTALLATION, BATTERY . . . 8F-14
HOLDDOWN - OPERATION, BATTERY.....8F-14
HOLDDOWN - REMOVAL, BATTERY......8F-14
HOLDER - INSTALLATION, CUP.........23-52
HOLDER - REMOVAL, CUP.............23-52
HOLDING CLUTCHES - DESCRIPTION....21-546
HOLDING CLUTCHES - OPERATION.....21-546
HOLE PLUG - INSTALLATION, CAMSHAFT
CORE..............................9-201
HOLE PLUG - REMOVAL, CAMSHAFT
CORE..............................9-200
HOLE REPAIR - DESCRIPTION,
THREADED........................Intro.-9
HONING - STANDARD PROCEDURE,
CYLINDER BORE.......9-126,9-233,9-360,9-37
HOOD - INSTALLATION................23-47
HOOD - REMOVAL....................23-47
HOOK - INSTALLATION, COAT...........23-67
HOOK - REMOVAL, COAT..............23-67
HOOK ASSEMBLY - INSTALLATION,
FRONT TOW........................13-26
HOOK ASSEMBLY - REMOVAL, FRONT
TOW ..............................13-26
HORN - DIAGNOSIS AND TESTING.......8H-1
HORN - INSTALLATION.................8H-2
HORN - REMOVAL....................8H-2
HORN SWITCH - DESCRIPTION..........8H-2
HORN SWITCH - DIAGNOSIS AND
TESTING............................8H-2
HORN SYSTEM - DESCRIPTION..........8H-1
HORN SYSTEM - DIAGNOSIS AND
TESTING............................8H-1
HORN SYSTEM - OPERATION............8H-1
HOSE - GEAR TO COOLER -
INSTALLATION, RETURN..........19-43,19-44
HOSE - GEAR TO COOLER - REMOVAL,
RETURN............................19-43
HOSE - INSTALLATION, FRONT BRAKE......5-9
HOSE - INSTALLATION, PRESSURE . 19-43,19-44
HOSE - INSTALLATION, REAR BRAKE.......5-9
HOSE - REMOVAL, FRONT...............5-9
HOSE - REMOVAL, PRESSURE.....19-43,19-44
HOSE - REMOVAL, REAR BRAKE..........5-8
HOSE - RESERVOIR TO COOLER -
INSTALLATION, RETURN..........19-43,19-44
HOSE - RESERVOIR TO COOLER -
REMOVAL, RETURN.............19-43,19-44
HOSE ASSEMBLY - INSTALLATION, REAR
TUBE................................5-9
HOSE ASSEMBLY - REMOVAL, REAR
TUBE................................5-8
HOSE CLAMPS - DESCRIPTION...........7-3
HOSE CLAMPS - OPERATION.............7-5
HOSE WITH AIR CONDITIONING -
INSTALLATION, WATER PUMP BYPASS....7-70
HOSE WITH AIR CONDITIONING -
REMOVAL, WATER PUMP BYPASS........7-68
HOSE WITHOUT AIR CONDITIONING -
INSTALLATION, WATER PUMP BYPASS....7-70
HOSE WITHOUT AIR CONDITIONING -
REMOVAL, WATER PUMP BYPASS........7-69
HOSES/LINES/TUBES PRECAUTIONS -
CAUTION, REFRIGERANT..............24-33
HOSES/TUBES - DESCRIPTION, WASHER . 8R-11
HOSES/TUBES - OPERATION, WASHER . . . 8R-11
HOUSING - ASSEMBLY, HVAC
...........24-28
HOUSING - DIAGNOSIS AND TESTING,
CLUTCH
..............................6-8
HOUSING - DISASSEMBLY, HVAC
........24-28
HOUSING - INSTALLATION, CLUTCH
......6-10
HOUSING - INSTALLATION, GEAR
........9-349HOUSING - INSTALLATION, HVAC........24-29
HOUSING - INSTALLATION, ROCKER.....9-304
HOUSING - REMOVAL, CLUTCH..........6-10
HOUSING - REMOVAL, GEAR...........9-348
HOUSING - REMOVAL, HVAC...........24-27
HOUSING - REMOVAL, ROCKER.........9-304
HOUSING BUSHING - INSTALLATION,
EXTENSION........................21-200
HOUSING BUSHING - REMOVAL,
EXTENSION........................21-200
HOUSING BUSHING AND SEAL -
INSTALLATION, EXTENSION.....21-616,21-682
HOUSING BUSHING AND SEAL -
REMOVAL, EXTENSION.........21-616,21-682
HOUSING COVER - INSTALLATION, GEAR . 9-350
HOUSING COVER - REMOVAL, GEAR.....9-349
HOUSING FLUID LEAK - DIAGNOSIS AND
TESTING, CONVERTER . . . 21-143,21-324,21-495
HOUSING SEAL - INSTALLATION,
ADAPTER...............21-127,21-539,21-83
HOUSING SEAL - INSTALLATION,
EXTENSION.......21-127,21-200,21-380,21-83
HOUSING SEAL - REMOVAL, ADAPTER . . 21-127,
21-539,21-83
HOUSING SEAL - REMOVAL,
EXTENSION.......21-127,21-200,21-380,21-83
HOUSING SEAL AND DUST BOOT -
INSTALLATION, EXTENSION.....21-652,21-716
HOUSING SEAL AND DUST BOOT -
REMOVAL, EXTENSION.........21-652,21-716
HOW TO USE WIRING DIAGRAMS -
DESCRIPTION.....................8W-01-1
H-SECTION REPLACEMENT - STANDARD
PROCEDURE, REAR FRAME............13-15
HUB / BEARING - INSTALLATION.........2-31
HUB / BEARING - REMOVAL.............2-30
HVAC HOUSING - ASSEMBLY...........24-28
HVAC HOUSING - DISASSEMBLY........24-28
HVAC HOUSING - INSTALLATION........24-29
HVAC HOUSING - REMOVAL............24-27
HYDRAULIC BOOSTER - DIAGNOSIS
AND TESTING........................5-25
HYDRAULIC LASH ADJUSTER -
DIAGNOSIS AND TESTING.........9-124,9-31
HYDRAULIC LIFTERS - CLEANING . . 9-260,9-388
HYDRAULIC LIFTERS - INSTALLATION . . . 9-260,
9-388
HYDRAULIC LIFTERS - REMOVAL . . . 9-259,9-387
HYDRAULIC PRESSURE TEST -
DIAGNOSIS AND TESTING......21-140,21-321,
21-493
HYDRAULIC SCHEMATICS, SCHEMATICS
AND DIAGRAMS........21-175,21-355,21-513
HYDRAULIC TAPPETS - DIAGNOSIS AND
TESTING......................9-258,9-386
HYDROBOOST - INSTALLATION..........5-22
HYDROBOOST - INSTALLATION, ALL
EXCEPT.............................5-22
HYDROBOOST - REMOVAL..............5-21
HYDROBOOST - REMOVAL, ALL EXCEPT . . . 5-21
HYDRO-BOOST BRAKE BOOSTER -
INSTALLATION........................5-27
HYDRO-BOOST BRAKE BOOSTER -
REMOVAL...........................5-27
HYDROFORM FENDER RAIL REPAIR -
STANDARD PROCEDURE...............13-12
HYDROSTATIC LOCK - STANDARD
PROCEDURE.........9-186,9-232,9-290,9-361
IDENTIFICATION - DESCRIPTION,
FASTENER.........................Intro.-6
IDENTIFICATION AND INFORMATION -
DESCRIPTION, SECTION.............8W-01-6
IDENTIFICATION NUMBER -
DESCRIPTION, VEHICLE..............Intro.-2
IDLE AIR CONTROL MOTOR -
DESCRIPTION.......................14-33
IDLE AIR CONTROL MOTOR -
INSTALLATION.......................14-35
IDLE AIR CONTROL MOTOR -
OPERATION.........................14-33
IDLE AIR CONTROL MOTOR - REMOVAL . . 14-34
IDLER SHAFT - INSTALLATION......9-175,9-80
IDLER SHAFT - REMOVAL
..........9-175,9-79
IGNITION - SPECIFICATIONS, TORQUE
.....8I-3
IGNITION CIRCUIT SENSE -
DESCRIPTION
.......................8E-10
IGNITION CIRCUIT SENSE - OPERATION
. . 8E-12
IGNITION COIL - DESCRIPTION
..........8I-19IGNITION COIL - INSTALLATION.........8I-24
IGNITION COIL - OPERATION............8I-20
IGNITION COIL - REMOVAL.............8I-23
IGNITION COIL CAPACITOR -
DESCRIPTION........................8I-33
IGNITION COIL CAPACITOR -
INSTALLATION.......................8I-33
IGNITION COIL CAPACITOR - OPERATION . . 8I-33
IGNITION COIL CAPACITOR - REMOVAL . . . 8I-33
IGNITION COIL RESISTANCE, 3.7L V-6.....8I-6
IGNITION COIL RESISTANCE, 4.7L V-8.....8I-6
IGNITION COIL RESISTANCE, 5.7L V-8.....8I-6
IGNITION COIL RESISTANCE, 5.9L.........8I-6
IGNITION COIL RESISTANCE, 8.0L V-10
ENGINE..............................8I-6
IGNITION CONTROL - DESCRIPTION.......8I-1
IGNITION SWITCH - DESCRIPTION........19-9
IGNITION SWITCH - DESCRIPTION,
KEY-IN.............................19-11
IGNITION SWITCH - DIAGNOSIS AND
TESTING............................19-9
IGNITION SWITCH - INSTALLATION......19-11
IGNITION SWITCH - OPERATION.........19-9
IGNITION SWITCH - REMOVAL..........19-10
IGNITION SWITCH AND KEY LOCK
CYLINDER - DIAGNOSIS AND TESTING . . . 19-11
IGNITION TIMING, SPECIFICATIONS.......8I-6
IGNITION-OFF DRAW TEST - STANDARD
PROCEDURE..........................8F-11
IMMOBILIZER MODULE - DESCRIPTION,
SENTRY KEY........................8E-13
IMMOBILIZER MODULE - INSTALLATION,
SENTRY KEY........................8E-15
IMMOBILIZER MODULE - OPERATION,
SENTRY KEY........................8E-13
IMMOBILIZER MODULE - REMOVAL,
SENTRY KEY........................8E-15
IMMOBILIZER SYSTEM INDICATOR
LAMP - DESCRIPTION, SENTRY KEY......8Q-5
IMMOBILIZER SYSTEM INDICATOR
LAMP - OPERATION, SENTRY KEY........8Q-5
IMMOBILIZER SYSTEM INITIALIZATION,
STANDARD PROCEDURE - SENTRY
KEY................................8Q-3
IMMOBILIZER SYSTEM (SKIS),
DESCRIPTION - SENTRY KEY............8Q-1
IMMOBILIZER SYSTEM TRANSPONDER
PROGRAMMING, STANDARD
PROCEDURE - SENTRY KEY.............8Q-4
IMPACT AIRBAG CONTROL MODULE -
DESCRIPTION, SIDE..................8O-53
IMPACT AIRBAG CONTROL MODULE -
OPERATION, SIDE....................8O-54
INCORRECT FLUID LEVEL - DIAGNOSIS
AND TESTING, EFFECTS OF.....21-201,21-381,
21-541
INDEPENDENT FRONT SUSPENSION -
DESCRIPTION, GEAR..................19-16
INDEPENDENT FRONT SUSPENSION -
INSTALLATION, GEAR.................19-17
INDEPENDENT FRONT SUSPENSION -
REMOVAL, GEAR.....................19-16
INDICATOR - DESCRIPTION, ABS........8J-17
INDICATOR - DESCRIPTION, AIRBAG.....8J-18
INDICATOR - DESCRIPTION, BRAKE/
PARK BRAKE........................8J-18
INDICATOR - DESCRIPTION, CARGO
LAMP..............................8J-20
INDICATOR - DESCRIPTION, CHECK
GAUGES............................8J-21
INDICATOR - DESCRIPTION, CRUISE.....8J-22
INDICATOR - DESCRIPTION, DOOR AJAR . . 8J-23
INDICATOR - DESCRIPTION, ETC........8J-24
INDICATOR - DESCRIPTION, GEAR
SELECTOR..........................8J-26
INDICATOR - DESCRIPTION, HIGH BEAM . . 8J-27
INDICATOR - DESCRIPTION, LAMP OUT . . . 8J-28
INDICATOR - DESCRIPTION, LOW FUEL . . . 8J-29
INDICATOR - DESCRIPTION, OVERDRIVE
OFF ...............................8J-33
INDICATOR - DESCRIPTION, SEATBELT
. . . 8J-34
INDICATOR - DESCRIPTION, SECURITY
. . . 8J-34
INDICATOR - DESCRIPTION, SERVICE
4WD
...............................8J-35
INDICATOR - DESCRIPTION, TRANS
TEMP
..............................8J-38
INDICATOR - DESCRIPTION, TURN
SIGNAL
............................8J-39
DRINDEX 17
Description Group-Page Description Group-Page Description Group-Page