Emissions DODGE TOWN AND COUNTRY 2003 User Guide

REMOVAL
When replacing the spark plugs and spark plug
cables, route the cables correctly and secure them in
the appropriate retainers. Failure to route the cables
properly can cause the radio to reproduce ignition
noise, cross ignition of the spark plugs orshort cir-
cuit the cables to ground.
Always remove cables by grasping at the boot,
rotating the boot 1/2 turn, and pulling straight back
in a steady motion.
(1) Prior to removing the spark plug, spray com-
pressed air around the spark plug hole and the area
around the spark plug.
(2) Remove the spark plug using a quality socket
with a foam insert.
(3) Inspect the spark plug condition.
INSTALLATION
When replacing the spark plugs and spark plug
cables, route the cables correctly and secure them in
the appropriate retainers. Failure to route the cables
properly can cause the radio to reproduce ignition
noise, cross ignition of the spark plugs orshort cir-
cuit the cables to ground.
(1) Coat threads of spark plug with anti-seize. Be
sure not to get anti-seizeANTWHERE BUT ON
THE THREADS OF THE SPARK PLUG as
shown in (Fig. 13).
(2) To avoid cross threading, start the spark plug
into the cylinder head by hand.
(3) Tighten spark plugs to 17.5 N´m (13 ft. lbs.)
torque.
(4) Install spark plug cables over spark plugs. A
click will be heard and felt when the cable properly
attaches to the spark plug.
SPARK PLUG CABLE
DESCRIPTION
Spark Plug cables are sometimes referred to as
secondary ignition wires. The wires transfer electri-
cal current from the ignition coil pack to individual
spark plugs at each cylinder. The resistive spark plug
cables are of nonmetallic construction. The cables
provide suppression of radio frequency emissions
from the ignition system.
Check the spark plug cable connections for good
contact at the coil, and spark plugs. Terminals should
be fully seated. The insulators should be in good con-
dition and should fit tightly on the coil, and spark
plugs. Spark plug cables with insulators that are
cracked or torn must be replaced.
Clean Spark Plug cables with a cloth moistened
with a non-flammable solvent. Wipe the cables dry.
Check for brittle or cracked insulation. The spark
plug cables and spark plug boots are made from high
temperature materials.
REMOVAL - 2.0/2.4L
Failure to route the cables properly could cause the
radio to reproduce ignition noise, cross ignition of the
spark plugs or short circuit the cables to ground.
Remove spark plug cable from coil first.
Always remove the spark plug cable by grasping
the top of the spark plug insulator, turning the boot
1/2 turn and pulling straight up in a steady motion.
INSTALLATION - 2.0/2.4L
Failure to route the cables properly could cause the
radio to reproduce ignition noise, cross ignition of the
spark plugs or short circuit the cables to ground.
Install spark plug insulators over spark plugs.
Ensure the top of the spark plug insulator covers the
upper end of the spark plug tube, then connect the
other end to coil pack.
8I - 10 IGNITION CONTROLRS
SPARK PLUG (Continued)
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CONDITION POSSIBLE CAUSES CORRECTION
OIL CONSUMPTION OR SPARK
PLUGS FOULED1. PCV system malfunction. 1. Check system and repair as
necessary. (Refer to 25 -
EMISSIONS CONTROL/
EVAPORATIVE EMISSIONS/PCV
VALVE - DIAGNOSIS AND
TESTING)
2. Worn, scuffed or broken rings. 2. Hone cylinder bores. Install new
rings.
3. Carbon in oil ring slots. 3. Install new rings.
4. Rings fitted too tightly in grooves. 4. Remove rings and check
grooves. If groove is not proper
width, replace piston.
5. Worn valve guide(s). 5. Replace cylinder head assembly.
6. Valve stem seal(s) worn or
damaged.6. Replace seal(s).
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
INSPECTION
Begin with a thorough visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.
(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair as necessary.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.
(5)If the oil leak source is not positively
identified at this time, proceed with the air leak
detection test method as follows:
²Disconnect the fresh air hose (make-up air) at
the cylinder head cover and plug or cap the nipple on
the cover.
²Remove the PCV valve hose from the cylinder
head cover. Cap or plug the PCV valve nipple on the
cover.
²Attach an air hose with pressure gauge and reg-
ulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.²Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provides the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
²If the leakage occurs at the crankshaft rear oil
seal area, refer to the section, Inspection for Rear
Seal Area Leak.
(6) If no leaks are detected, turn off the air supply.
Remove the air hose, all plugs, and caps. Install the
PCV valve and fresh air hose (make-up air). Proceed
to next step.
(7) Clean the oil off the suspect oil leak area using
a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
NOTE: If oil leakage is observed at the dipstick tube
to block location; remove the tube, clean and reseal
using MoparTStud & Bearing Mount (press fit tube
applications only), and for O-ring style tubes,
remove tube and replace the O-ring seal.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
9 - 8 ENGINE 2.4LRS
ENGINE 2.4L (Continued)
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(9) Disconnect throttle and speed control (if
equipped) cables from throttle lever and bracket.
(Refer to 14 - FUEL SYSTEM/FUEL INJECTION/
THROTTLE CONTROL CABLE - REMOVAL)
(10) Remove the EGR tube. (Refer to 25 - EMIS-
SIONS CONTROL/EXHAUST GAS RECIRCULA-
TION/TUBE - REMOVAL)
(11) Remove the upper manifold support bracket
bolt to manifold (Fig. 105).
(12) Remove engine oil dipstick from tube.
(13) Remove upper intake manifold bolts (Fig.
106). Remove upper intake manifold.
CAUTION: Cover intake manifold to prevent foreign
material from entering engine.
INSPECTION
(1) Check manifold surfaces for flatness with
straight edge. Surface must be flat within 0.15 mm
per 300 mm (0.006 in. per foot) of manifold length.
(2) Inspect manifold for cracks or distortion.
Replace manifold if necessary.
INSTALLATION
(1) Clean manifold sealing surfaces.
(2) Apply a 1.5 mm (0.060 in.) bead MopartGas-
ket Maker to the perimeter of the lower intake man-
ifold runner openings.
(3) Install upper intake manifold and tighten fas-
teners to 28 N´m (250 in. lbs.) in sequence shown in
(Fig. 106). Repeat this procedures until all fasteners
are at specified torque.
(4) Install engine oil dipstick.
(5) Install upper bolt in intake manifold to front
support bracket (Fig. 105). Torque to 28 N´m (250 in.
lbs.).
(6) Install EGR tube. (Refer to 25 - EMISSIONS
CONTROL/EXHAUST GAS RECIRCULATION/
TUBE - INSTALLATION)
(7) Install throttle cables in bracket.
(8) Connect throttle and speed control (if equipped)
cables to throttle lever.
(9) Connect vacuum lines for power brake booster,
LDP, EGR transducer, and speed control vacuum res-
ervoir (if equipped) at upper intake manifold fittings.
(10) Connect vacuum lines for purge solenoid and
PCV valve.
(11) Connect electrical connectors for MAP sensor,
throttle position sensor (TPS), and idle air control
(IAC) motor.
(12) Install air cleaner upper housing and air
intake tube to throttle body.
(13) Connect inlet air temperature sensor connec-
tor (Fig. 102).
(14) Connect negative cable to battery.
Fig. 104 Throttle Body Electrical Connectors -
Typical
1 - IDLE AIR CONTROL MOTOR CONNECTOR
2 - TPS CONNECTOR
Fig. 105 Upper Intake Manifold Support Bracket
1 - NUT - BRACKET TO CYLINDER HEAD COVER
2 - BOLT - BRACKET TO UPPER INTAKE MANIFOLD
3 - UPPER INTAKE MANIFOLD SUPPORT BRACKET
Fig. 106 Upper Intake Manifold Tightening Sequence
- 2.4L
RSENGINE 2.4L9-59
INTAKE MANIFOLD - UPPER (Continued)
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CONDITION POSSIBLE CAUSES CORRECTION
OIL CONSUMPTION OR SPARK
PLUGS FOULED1. PCV system malfunction. 1. Check system and repair as
necessary. (Refer to 25 -
EMISSIONS CONTROL/
EVAPORATIVE EMISSIONS/PCV
VALVE - DIAGNOSIS AND
TESTING)
2. Worn, scuffed or broken rings. 2. Hone cylinder bores. Install new
rings.
3. Carbon in oil ring slots. 3. Install new rings.
4. Rings fitted too tightly in grooves. 4. Remove rings and check
grooves. If groove is not proper
width, replace piston.
5. Worn valve guide(s). 5. Replace cylinder head assembly.
6. Valve stem seal(s) worn or
damaged.6. Replace seal(s).
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
INSPECTION
Begin with a thorough visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.
(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair as necessary.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.
(5)If the oil leak source is not positively
identified at this time, proceed with the air leak
detection test method as follows:
²Disconnect the fresh air hose (make-up air) at
the cylinder head cover and plug or cap the nipple on
the cover.
²Remove the PCV valve hose from the cylinder
head cover. Cap or plug the PCV valve nipple on the
cover.
²Attach an air hose with pressure gauge and reg-
ulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.²Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provides the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
²If the leakage occurs at the crankshaft rear oil
seal area, refer to the section, Inspection for Rear
Seal Area Leak.
(6) If no leaks are detected, turn off the air supply.
Remove the air hose, all plugs, and caps. Install the
PCV valve and fresh air hose (make-up air). Proceed
to next step.
(7) Clean the oil off the suspect oil leak area using
a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
NOTE: If oil leakage is observed at the dipstick tube
to block location; remove the tube, clean and reseal
using MoparTStud & Bearing Mount (press fit tube
applications only), and for O-ring style tubes,
remove tube and replace the O-ring seal.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
9 - 82 ENGINE 3.3/3.8LRS
ENGINE 3.3/3.8L (Continued)
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SPECIAL TOOLS
EXHAUST SYSTEM
CATALYTIC CONVERTER
DESCRIPTION
The toe board three-way catalytic converter is con-
nected to the exhaust manifold by the use of flex
joint and a gasket. The outlet connects to the muffler
inlet pipe and is secured with a band type clamp
(Fig. 1).
The exhaust flex-joint coupling (Fig. 3) is used to
secure the catalytic converter to the exhaust manifold.
The flex-joint has four bolts, four flag nuts and a gas-
ket that are separate parts from the exhaust flex-joint.
The flex-joint is welded to the catalytic converter.
CAUTION: When servicing, care must be exercised
not to dent or bend the bellows or bellows cover of
the flex-joint. Should this occur, the flex-joint will
eventually fail and require the catalytic converter be
replaced.
OPERATION
The three-way catalytic converter simultaneously
converts three exhaust emissions into harmless
gases. Specifically, HC and CO emissions are con-
verted into water (H2O) and carbon dioxide (CO2).
Oxides of Nitrogen (NOx) are converted into elemen-
tal Nitrogen (N) and water. The three-way catalyst is
most efficient in converting HC, CO and NOx at the
stoichiometric air fuel ratio of 14.7:1.
The oxygen content in a catalyst is important for
efficient conversion of exhaust gases. When a high
oxygen content (lean) air/fuel ratio is present for an
extended period, oxygen content in a catalyst can
reach a maximum. When a rich air/fuel ratio is
present for an extended period, the oxygen content in
the catalyst can become totally depleted. When this
occurs, the catalyst fails to convert the gases. This is
known as catalyst9punch through.9
Catalyst operation is dependent on its ability to
store and release the oxygen needed to complete the
emissions-reducing chemical reactions. As a catalyst
deteriorates, its ability to store oxygen is reduced.
Since the catalyst's ability to store oxygen is some-
what related to proper operation, oxygen storage can
be used as an indicator of catalyst performance.
Refer to the appropriate Diagnostic Information for
diagnosis of a catalyst related Diagnostic Trouble
Code (DTC).
Back Pressure Test Adapter - CH8519
Pressure Transducer CH7063
DRB III & PEP Module - OT-CH6010A
Fig. 3 Flex-joint
1 - FLANGE
2 - END CAPS
3 - CATALYTIC CONVERTER
4 - FLEXIBLE BELLOWS
11 - 4 EXHAUST SYSTEMRS
EXHAUST SYSTEM (Continued)
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(7) Remove fuel rail. Be careful not to damage the
injector O-rings upon removal from their ports.
INSTALLATION
INSTALLATION - 2.4L
(1) Ensure injector holes are clean. Replace
O-rings if damaged.
(2) Lubricate injector O-rings with a drop of clean
engine oil to ease installation.
(3) Put the tip of each injector into their ports.
Push the assembly into place until the injectors are
seated in the ports.
(4) Install the fuel rail mounting bolts. Tighten
bolts to 22 N´m (200 in. lbs.) torque.
(5) Connect the connectors to the fuel injectors.
(6) Install wiring harness to brackets.
(7) Connect the wiring connectors to fuel injectors
harness (Fig. 13).
(8) Connect negative battery cable.
(9) Use the DRBIIItscan tool to pressurize the
fuel system. Check for leaks.
INSTALLATION - 3.3/3.8L
(1) Ensure injector holes are clean. Replace
O-rings if damaged.
(2) Lubricate injector O-rings with a drop of clean
engine oil to ease installation.
(3) Put the tip of each injector into their ports.
Push the assembly into place until the injectors are
seated in the ports.
(4) Install the fuel rail mounting bolts. Tighten
bolts to 22 N´m (200 in. lbs.) torque.
(5) Remove covering on lower intake manifold and
clean surface.(6) Install the Upper Intake Manifold, refer to
Engine/Manifolds/Upper Intake for more information.
(7) Install fuel hose quick connector fitting to chas-
sis tubes.Refer to Fuel Hoses, Clamps and
Quick Connect Fittings in this Section.Push the
fitting onto the chassis tube until it clicks into place.
Pull on the fitting to ensure complete insertion.
(8) Connect negative cable to battery.
(9) Use the DRBIIItscan tool to pressurize the
fuel system. Check for leaks.
FUEL TANK
DESCRIPTION
The fuel tank is constructed of a plastic material.
Its main functions are for fuel storage and for place-
ment of the fuel pump module. The tank is made
from High density Polyethylene (HDPE) material.If
equipped with ORVR (Onboard Refueling Vapor
Recovery) it has been added to the fuel tank to con-
trol refueling vapor emissions.
OPERATION
All models pass a full 360 degree rollover test
without fuel leakage. To accomplish this, fuel and
vapor flow controls are required for all fuel tank con-
nections.
All models are equipped with either one or two
rollover valves mounted into the top of the fuel tank
(or pump module).
An evaporation control system is connected to the
rollover valve(s)/control valve(Refer to 25 - EMIS-
SIONS CONTROL/EVAPORATIVE EMISSIONS/
ORVR - OPERATION) to reduce emissions of fuel
vapors into the atmosphere, when the tank is vented
due to vapor expansion in the tank. When fuel evap-
orates from the fuel tank, vapors pass through vent
hoses or tubes to a charcoal canister where they are
temporarily held. When the engine is running, the
vapors are drawn into the intake manifold. In addi-
tion, fuel vapors produced during vehicle refueling
are allowed to pass through the vent hoses/tubes to
the charcoal canister(s) for temporary storage (prior
to being drawn into the intake manifold). All models
are equipped with a self-diagnosing system using a
Leak Detection Pump (LDP) or Natural Vacuum
Leak Detection (NVLD). Refer to the Emission Con-
trol System for additional information.
INLET CHECK VALVE
All vehicles have an inlet check valve on the inside
of the fuel tank at the filler inlet
The valve prevents fuel from splashing back on
customer during vehicle refueling. The valve is a
non-serviceable item.
Fig. 14 FUEL INJECTORS 3.3/3.8L
14 - 10 FUEL DELIVERYRS
FUEL RAIL (Continued)
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FUEL INJECTION
OPERATION
OPERATION - INJECTION SYSTEM
All engines used in this section have a sequential
Multi-Port Electronic Fuel Injection system. The MPI
system is computer regulated and provides precise
air/fuel ratios for all driving conditions. The Power-
train Control Module (PCM) operates the fuel injec-
tion system.
The PCM regulates:
²Ignition timing
²Air/fuel ratio
²Emission control devices
²Cooling fan
²Charging system
²Idle speed
²Vehicle speed control
Various sensors provide the inputs necessary for
the PCM to correctly operate these systems. In addi-
tion to the sensors, various switches also provide
inputs to the PCM.
The PCM can adapt its programming to meet
changing operating conditions.
Fuel is injected into the intake port above the
intake valve in precise metered amounts through
electrically operated injectors. The PCM fires the
injectors in a specific sequence. Under most operat-
ing conditions, the PCM maintains an air fuel ratio
of 14.7 parts air to 1 part fuel by constantly adjust-
ing injector pulse width. Injector pulse width is the
length of time the injector is open.
The PCM adjusts injector pulse width by opening
and closing the ground path to the injector. Engine
RPM (speed) and manifold absolute pressure (air
density) are theprimaryinputs that determine
injector pulse width.
OPERATION - MODES OF OPERATION
As input signals to the PCM change, the PCM
adjusts its response to output devices. For example,
the PCM must calculate a different injector pulse
width and ignition timing for idle than it does for
Wide Open Throttle (WOT). There are several differ-
ent modes of operation that determine how the PCM
responds to the various input signals.
There are two different areas of operation, OPEN
LOOP and CLOSED LOOP.
During OPEN LOOP modes the PCM receives
input signals and responds according to preset PCM
programming. Inputs from the upstream and down-
stream heated oxygen sensors are not monitored dur-
ing OPEN LOOP modes, except for heated oxygensensor diagnostics (they are checked for shorted con-
ditions at all times).
During CLOSED LOOP modes the PCM monitors
the inputs from the upstream and downstream
heated oxygen sensors. The upstream heated oxygen
sensor input tells the PCM if the calculated injector
pulse width resulted in the ideal air-fuel ratio of 14.7
to one. By monitoring the exhaust oxygen content
through the upstream heated oxygen sensor, the
PCM can fine tune injector pulse width. Fine tuning
injector pulse width allows the PCM to achieve opti-
mum fuel economy combined with low emissions.
For the PCM to enter CLOSED LOOP operation,
the following must occur:
(1) Engine coolant temperature must be over 35ÉF.
²If the coolant is over 35ÉF the PCM will wait 38
seconds.
²If the coolant is over 50ÉF the PCM will wait 15
seconds.
²If the coolant is over 167ÉF the PCM will wait 3
seconds.
(2) For other temperatures the PCM will interpo-
late the correct waiting time.
(3) O2 sensor must read either greater than 0.745
volts or less than 0.29 volt.
(4) The multi-port fuel injection systems has the
following modes of operation:
²Ignition switch ON (Zero RPM)
²Engine start-up
²Engine warm-up
²Cruise
²Idle
²Acceleration
²Deceleration
²Wide Open Throttle
²Ignition switch OFF
(5) The engine start-up (crank), engine warm-up,
deceleration with fuel shutoff and wide open throttle
modes are OPEN LOOP modes. Under most operat-
ing conditions, the acceleration, deceleration (with
A/C on), idle and cruise modes,with the engine at
operating temperatureare CLOSED LOOP modes.
IGNITION SWITCH ON (ZERO RPM) MODE
When the ignition switch activates the fuel injec-
tion system, the following actions occur:
²The PCM monitors the engine coolant tempera-
ture sensor and throttle position sensor input. The
PCM determines basic fuel injector pulse width from
this input.
²The PCM determines atmospheric air pressure
from the MAP sensor input to modify injector pulse
width.
When the key is in the ON position and the engine
is not running (zero rpm), the Auto Shutdown (ASD)
and fuel pump relays de-energize after approximately
14 - 18 FUEL INJECTIONRS
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²All monitored components (refer to the Emission
section for On-Board Diagnostics).
The PCM compares the upstream and downstream
heated oxygen sensor inputs to measure catalytic
convertor efficiency. If the catalyst efficiency drops
below the minimum acceptable percentage, the PCM
stores a diagnostic trouble code in memory, after 2
trips.
During certain idle conditions, the PCM may enter
a variable idle speed strategy. During variable idle
speed strategy the PCM adjusts engine speed based
on the following inputs.
²A/C status
²Battery voltage
²Battery temperature or Calculated Battery Tem-
perature
²Engine coolant temperature
²Engine run time
²Inlet/Intake air temperature
²Vehicle mileage
ACCELERATION MODE
This is a CLOSED LOOP mode. The PCM recog-
nizes an abrupt increase in Throttle Position sensor
output voltage or MAP sensor output voltage as a
demand for increased engine output and vehicle
acceleration. The PCM increases injector pulse width
in response to increased fuel demand.
²Wide Open Throttle-open loop
DECELERATION MODE
This is a CLOSED LOOP mode. During decelera-
tion the following inputs are received by the PCM:
²A/C status
²Battery voltage
²Inlet/Intake air temperature
²Engine coolant temperature
²Crankshaft position (engine speed)
²Exhaust gas oxygen content (upstream heated
oxygen sensor)
²Knock sensor
²Manifold absolute pressure
²Throttle position sensor
²IAC motor (solenoid) control changes in response
to MAP sensor feedback
The PCM may receive a closed throttle input from
the Throttle Position Sensor (TPS) when it senses an
abrupt decrease in manifold pressure. This indicates
a hard deceleration (Open Loop). In response, the
PCM may momentarily turn off the injectors. This
helps improve fuel economy, emissions and engine
braking.
WIDE-OPEN-THROTTLE MODE
This is an OPEN LOOP mode. During wide-open-
throttle operation, the following inputs are used by
the PCM:
²Inlet/Intake air temperature
²Engine coolant temperature
²Engine speed
²Knock sensor
²Manifold absolute pressure
²Throttle position
When the PCM senses a wide-open-throttle condi-
tion through the Throttle Position Sensor (TPS) it de-
energizes the A/C compressor clutch relay. This
disables the air conditioning system and disables
EGR (if equipped).
The PCM adjusts injector pulse width to supply a
predetermined amount of additional fuel, based on
MAP and RPM.
IGNITION SWITCH OFF MODE
When the operator turns the ignition switch to the
OFF position, the following occurs:
²All outputs are turned off, unless 02 Heater
Monitor test is being run. Refer to the Emission sec-
tion for On-Board Diagnostics.
²No inputs are monitored except for the heated
oxygen sensors. The PCM monitors the heating ele-
ments in the oxygen sensors and then shuts down.
FUEL CORRECTION or ADAPTIVE MEMORIES
DESCRIPTION
In Open Loop, the PCM changes pulse width with-
out feedback from the O2 Sensors. Once the engine
warms up to approximately 30 to 35É F, the PCM
goes into closed loopShort Term Correctionand
utilizes feedback from the O2 Sensors. Closed loop
Long Term Adaptive Memoryis maintained above
170É to 190É F unless the PCM senses wide open
throttle. At that time the PCM returns to Open Loop
operation.
OPERATION
Short Term
The first fuel correction program that begins func-
tioning is the short term fuel correction. This system
corrects fuel delivery in direct proportion to the read-
ings from the Upstream O2 Sensor.
The PCM monitors the air/fuel ratio by using the
input voltage from the O2 Sensor. When the voltage
reaches its preset high or low limit, the PCM begins
to add or remove fuel until the sensor reaches its
switch point. The short term corrections then begin.
The PCM makes a series of quick changes in the
injector pulse-width until the O2 Sensor reaches its
14 - 20 FUEL INJECTIONRS
FUEL INJECTION (Continued)
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(5) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE)
(6) Remove front wheel and tire assemblies.
(7) Remove front emissions vapor canister. (Refer
to 25 - EMISSIONS CONTROL/EVAPORATIVE
EMISSIONS/VAPOR CANISTER - REMOVAL)
(8) Remove a single hose at power steering cooler
and allow fluid to drain.
(9) Remove 2 bolts attaching power steering cooler
to cradle crossmember reinforcement (Fig. 3).
(10) On both sides of vehicle, remove nut attaching
outer tie rod end to steering knuckle (Fig. 4).
Remove nut by holding tie rod end stud with a
socket while loosening and removing nut with
wrench.
(11) Remove bolts fastening leak detection pump to
cradle crossmember reinforcement. (Refer to 25 -
EMISSIONS CONTROL/EVAPORATIVE EMIS-
SIONS/LEAK DETECTION PUMP - REMOVAL)
(12) Remove both outer tie rods from steering
knuckles, using Puller, Special Tool C-3894±A (Fig.
5).
(13) Remove the lower control arm rear bushing
retainer bolts located on each side of each lower con-
trol arm rear bushing.
NOTE: The bolts fastening the cradle crossmember
reinforcement are of two different thread sizes. Note
the location of the various sizes.
Fig. 3 Power Steering Cooler
1 - CRADLE CROSSMEMBER REINFORCEMENT
2 - POWER STEERING COOLER
Fig. 4 Removing/Installing Tie Rod End Attaching
Nut
1 - TIE ROD END
2 - STEERING KNUCKLE
3 - WRENCH
4 - SOCKET
5 - TIE ROD END STUD
Fig. 5 Tie Rod Removal With Tool C-3894-A
1 - OUTER TIE ROD
2 - SPECIAL TOOL C-3894-A
3 - STEERING KNUCKLE
19 - 28 GEARRS
GEAR (Continued)
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CAUTION: Proper torque on the cradle reinforce-
ment to suspension cradle mounting bolts is very
important.
(7) Install the reinforcement on the front suspen-
sion cradle crossmember and install the bolts attach-
ing the reinforcement to the cradle crossmember
(Fig. 6). Tighten the M-14 size bolts to a torque of
153 N´m (113 ft. lbs.). Tighten the M-12 size bolts to
a torque of 106 N´m (78 ft. lbs.).
(8) Install the lower control arm rear bushing
retainer bolts (M-10 size) through reinforcement on
each side of each lower control arm rear bushing.
Tighten bolts to a torque of 61 N´m (45 ft. lbs.).
(9) Install the two bolts and bushings attaching
the reinforcement and rear of cradle crossmember to
body of vehicle (Fig. 6). Tighten bolts to a torque of
163 N´m (120 ft. lbs.).
(10) Install outer tie rod end into steering knuckle.
Start outer tie rod to steering knuckle attaching nut
onto stud of tie rod end. While holding stud of tie rod
end stationary using a socket (Fig. 4), tighten tie rod
end to steering knuckle attaching nut. Then using a
crowfoot and socket (Fig. 13), tighten the tie rod end
attaching nut to a torque of 75 N´m (55 ft. lbs.).
(11) Install leak detection pump on cradle cross-
member reinforcement. (Refer to 25 - EMISSIONS
CONTROL/EVAPORATIVE EMISSIONS/LEAK
DETECTION PUMP - INSTALLATION)
(12) Install the power steering fluid cooler on the
cradle crossmember reinforcement (Fig. 3). Install
the mounting bolts and tighten to 11 N´m (100 in.
lbs.). When installing mounting bolts, include pres-
sure hose routing clamp.(13) Reconnect previously disconnected hose at
power steering cooler and install clamp.
(14) Install the front tire and wheel assemblies on
vehicle. Install the wheel lug nuts and torque to 135
N´m (100 ft. lbs.).
(15) Install front emissions vapor canister. (Refer
to 25 - EMISSIONS CONTROL/EVAPORATIVE
EMISSIONS/VAPOR CANISTER - INSTALLATION)
(16) Lower the vehicle to a level where the interior
of vehicle is accessible.
(17) With the wheels pointed approximately
STRAIGHT-AHEAD, align the intermediate shaft
with the steering column coupler. Assemble the steer-
ing column shaft coupler onto the steering gear inter-
mediate coupler (Fig. 2). Install steering column
coupler to intermediate shaft retaining pinch bolt.
Tighten the pinch bolt nut to a torque of 28 N´m (250
in. lbs.).
(18) Remove the steering wheel holding tool.
(19) Fill and bleed the power steering system
using the Power Steering Pump Initial Operation
Procedure. (Refer to 19 - STEERING/PUMP - STAN-
DARD PROCEDURE)
(20) Inspect system for leaks.
(21) Adjust front toe (Refer to 2 - SUSPENSION/
WHEEL ALIGNMENT - STANDARD PROCEDURE).
INSTALLATION - RHD GEAR
(1) Install the steering gear up in the front sus-
pension cradle crossmember, leaving room to install
intermediate coupler.
(2) Start the roll pin into the intermediate coupler
before installing coupler on steering gear shaft. Start
roll pin into coupler, using a hammer and tapping it
into the coupler. Then install the intermediate cou-
pler on the shaft of the steering gear.
(3) Install Remover/Installer Special Tool 6831A
through the center of the roll pin, securing it with
the knurled nut (Fig. 12). Hold threaded rod station-
ary while turning nut. This will pull the roll pin into
the intermediate coupler.
(4) Install power steering gear on the front suspen-
sion cradle. Install the 2 steering gear mounting
bolts and nuts. Tighten the M-14 size steering gear
to suspension cradle mounting bolt to a torque of 183
N´m (135 ft. lbs.). Tighten the M-12 size steering
gear to suspension cradle mounting bolt to a torque
of 95 N´m (70 ft. lbs.).
CAUTION: Proper torque on the steering gear to
suspension cradle mounting bolts is very impor-
tant.
(5) Install the heat shield on the steering gear
(Fig. 10).
(6) Attach the power steering fluid pressure and
return hoses to the proper fittings on the steering
Fig. 13 Torquing Tie Rod End Attaching Nut
1 - STEERING KNUCKLE
2 - TIE ROD END
3 - CROWFOOT
4 - SOCKET
5 - TORQUE WRENCH
RSGEAR19-33
GEAR (Continued)
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