frame CHRYSLER VOYAGER 2001 Service Manual

INSTALLATION
NOTE: Bench seats equipped with child restraint
seats have an interlock feature that will not allow
the seat back to fold forward with the child seat
open.
(1) Install the seat back.
(2) Install the shoulder bolts attaching the seat
back hinge to the seat back frame and tighten to 34
N´m (25 ft. lbs.) torque.
(3) Connect the synchronizing cable end from (clip
on left side) hinge latch release arm, if equipped.
(4) Connect the synchronizing cable housing to the
seat back hinge, if equipped.
(5) Install the upper hinge cover. (Refer to 23 -
BODY/SEATS/SEAT BACK HINGE - INSTALLA-
TION).
(6) Install the armrests, if equipped. (Refer to 23 -
BODY/SEATS/ARMREST - INSTALLATION).
(7) Install the headrest sleeves. (Refer to 23 -
BODY/SEATS/HEADREST SLEEVE - INSTALLA-
TION).
(8) Adjust synchronizing cable, if equipped. (Refer
to 23 - BODY/SEATS/SYNCHRONIZING CABLE
ADJUSTMENT).
BENCH SEAT BACK COVER
REMOVAL
(1) Remove the bench seat back. (Refer to 23 -
BODY/SEATS/BENCH SEAT BACK - REMOVAL).
(2) Remove the bench seatback panel. (Refer to 23
- BODY/SEATS/BENCH SEATBACK PANEL -
REMOVAL).
(3) Disconnect the cover J-straps.
(4) Remove the seat back cover from the seat back
assembly.
INSTALLATION
(1) Install seat back cover onto the seat back
frame and cushion assembly.
(2) Connect the J-straps.
(3) Install the bench seatback panel. (Refer to 23 -
BODY/SEATS/BENCH SEATBACK PANEL -
INSTALLATION).
(4) Install the seat back. (Refer to 23 - BODY/
SEATS/BENCH SEAT BACK - INSTALLATION).
BENCH SEAT TRACK
REMOVAL
(1) Remove second row seat from vehicle. Refer to
Owner's Manual for proper procedure.(2) Place seat on clean covered work surface.
(3) Disengage seat track adjuster link wire from
track being removed.
(4) Remove nuts attaching track to seat riser (Fig.
41).
(5) Remove track from seat riser.
INSTALLATION
(1) Place track in position on seat riser.
(2) Install nuts attaching track to seat riser. (Fig.
41). Tighten nuts to 48 N´m (35 ft. lbs.) torque.
(3) Engage seat track adjuster link wire onto track
being installed.
(4) Install second row seat into vehicle.
Fig. 41 BENCH SEAT TRACK
1 - SEAT TRACK ADJUSTER LINK
2 - RISER
3 - SEAT TRACK NUTS
4 - SEAT TRACK
5 - RISER BOLTS
23 - 240 SEATSRS
BENCH SEAT BACK (Continued)

PLASTIC GROCERY BAG
RETAINER
REMOVAL
3-PASS BENCH SEAT
(1) Remove five screws attaching the plastic gro-
cery bag retainer to the steel slats on the back frame
(Fig. 42).
(2) Remove retainer.
50/50 SPLIT BENCH SEAT
(1) Remove the screws. (Fig. 43)
(2) Pull top of retainer away from the seatback
and lift off of the two bottom attachment hooks.
INSTALLATION
3-PASS BENCH SEAT
(1) Place retainer in position.
(2) Install the five attaching screws and tighten 2
N´m (17 in. lbs.) torque.
50/50 SPLIT BENCH SEAT
(1) Engage bottom hooks of the retainer and place
into position.
(2) Install the attaching screws and tighten 2 N´m
(17 in. lbs.) torque.
UNDER SEAT STORAGE BIN
REMOVAL
(1) Release under seat storage bin latch and open
bin.
(2) Depress lock tabs at the rear/top edge of the
storage bin (Fig. 44) .
(3) Pull storage bin from bucket seat riser.
INSTALLATION
(1) Engage storage bin tracks into guides on each
side of seat riser.
(2) Push storage bin inward until lock tabs snap
past retaining ridge on tracks
(3) Verify storage bin latch operation.
Fig. 42 Plastic Grocery Bag Retainer
1 - SCREWS
2 - SCREWS
Fig. 43 Plastic Grocery Bag Retainer ± 50/50 SPLIT
1 - SEATBACK
2 - SCREWS
3 - SEATBACK PANEL
4 - GROCERY BAG RETAINER
5 - ATTACHMENT HOOKS
Fig. 44 Storage Bin
1 - PASS. SIDE BUCKET SEAT
2 - UNDER SEAT STORAGE BIN
3 - RISER
4 - LOCK TAB
RSSEATS23 - 241

UNDER SEAT STORAGE BIN
GUIDE
REMOVAL
(1) Remove under seat storage bin. (Refer to 23 -
BODY/SEATS/UNDER SEAT STORAGE BIN -
REMOVAL).
(2) Remove screws attaching storage bin track
guide to seat riser (Fig. 45).
(3) Remove track guide from vehicle.
INSTALLATION
(1) Place track guide in position on seat riser.
(2) Install screws attaching storage bin track guide
to seat riser (Fig. 45). Tighten screws to 81 N´m (32
in lbs.) torque.
(3) Install under seat storage bin. (Refer to 23 -
BODY/SEATS/UNDER SEAT STORAGE BIN -
INSTALLATION).
UNDER SEAT STORAGE BIN
LOCK/LATCH
REMOVAL
(1) Open under seat storage bin.
(2) Remove screws holding under seat storage bin
lock/latch to storage bin (Fig. 46).
(3) Remove lock/latch from bin.
INSTALLATION
(1) Place lock/latch in position on storage bin.
(2) Install screws to hold lock/latch to storage bin
(Fig. 46).
(3) Verify under seat storage bin latch operation.
LUMBAR SUPPORT
REMOVAL
(1) Remove screw attaching lumbar handle to seat
back (Fig. 47).
(2) Remove seat back assembly from cushion.
(3) Detrim the seat back assembly.
(4) Remove frame and replace.
INSTALLATION
(1) Trim the seat back frame.
(2) Install seat back assembly to cushion.
(3) Install attaching screw to lumbar handle. The
handle is to be installed, between two and three
O'clock position. Tighten screw to 1 N´m (11 ft. lbs.)
torque.
(4) Test lumbar operation.
Fig. 45 Under Seat Storage Bin Guide
1 - STORAGE BIN TRACK GUIDE
2 - RISER
Fig. 46 Under Seat Storage Bin Lock/Latch
1 - UNDER SEAT STORAGE BIN
2 - LOCK/LATCH
Fig. 47 Lumbar Handle
1 - LUMBAR HANDLE
23 - 242 SEATSRS

STATIONARY GLASS
TABLE OF CONTENTS
page page
WINDSHIELD
DESCRIPTION..........................243
WARNING.............................243
REMOVAL.............................243
INSTALLATION..........................244
SLIDING DOOR GLASS
REMOVAL.............................245INSTALLATION..........................245
QUARTER WINDOW
REMOVAL.............................246
INSTALLATION..........................246
REAR DOOR GLASS
REMOVAL.............................246
INSTALLATION..........................246
WINDSHIELD
DESCRIPTION
The windshield is attached to the window frame
with urethane adhesive. The urethane adhesive is
applied cold and seals the surface area between the
window opening and the glass. The primer adheres
the urethane adhesive to the windshield.
It is difficult to salvage a windshield during the
removal operation. The windshield is part of the
structural support for the roof. The urethane bonding
used to secure the windshield to the fence is difficult
to cut or clean from any surface. If the moldings are
set in urethane, it would also be unlikely they could
be salvaged. Before removing the windshield, check
the availability of the windshield and moldings from
the parts supplier.
WINDSHIELD SAFETY PRECAUTIONS
WARNING: DO NOT OPERATE THE VEHICLE
WITHIN 24 HOURS OF WINDSHIELD INSTALLATION.
IT TAKES AT LEAST 24 HOURS FOR URETHANE
ADHESIVE TO CURE. IF IT IS NOT CURED, THE
WINDSHIELD MAY NOT PERFORM PROPERLY IN
AN ACCIDENT.
URETHANE ADHESIVES ARE APPLIED AS A SYS-
TEM. USE GLASS CLEANER, GLASS PREP SOL-
VENT, GLASS PRIMER, PVC (VINYL) PRIMER AND
PINCH WELD (FENCE) PRIMER PROVIDED BY THE
ADHESIVE MANUFACTURER. IF NOT, STRUCTURAL
INTEGRITY COULD BE COMPROMISED.
DAIMLERCHRYSLER DOES NOT RECOMMEND
GLASS ADHESIVE BY BRAND. TECHNICIANS
SHOULD REVIEW PRODUCT LABELS AND TECHNI-
CAL DATA SHEETS, AND USE ONLY ADHESIVES
THAT THEIR MANUFACTURES WARRANT WILL
RESTORE A VEHICLE TO THE REQUIREMENTS OF
FMVSS 212. TECHNICIANS SHOULD ALSO INSURE
THAT PRIMERS AND CLEANERS ARE COMPATIBLEWITH THE PARTICULAR ADHESIVE USED.
BE SURE TO REFER TO THE URETHANE MANU-
FACTURER'S DIRECTIONS FOR CURING TIME
SPECIFICATIONS, AND DO NOT USE ADHESIVE
AFTER ITS EXPIRATION DATE.
VAPORS THAT ARE EMITTED FROM THE URE-
THANE ADHESIVE OR PRIMER COULD CAUSE
PERSONAL INJURY. USE THEM IN A WELL-VENTI-
LATED AREA.
SKIN CONTACT WITH URETHANE ADHESIVE
SHOULD BE AVOIDED. PERSONAL INJURY MAY
RESULT.
ALWAYS WEAR EYE AND HAND PROTECTION
WHEN WORKING WITH GLASS.
CAUTION: Protect all painted and trimmed surfaces
from coming in contact with urethane or primers.
Be careful not to damage painted surfaces when
removing moldings or cutting urethane around
windshield.
REMOVAL
WINDSHIELD REMOVAL ± EXTERIOR METHOD
The urethane adhesive holding the windshield to
the opening pinch weld (fence) can be cut using a
sharp cold knife from the exterior of the vehicle.
Using the cold knife method is effective if the wind-
shield is already broken. If the glass must be sal-
vaged, cutting the urethane adhesive from the
interior of the vehicle using a reciprocating or oscil-
lating power knife is recommended.
(1) Remove inside rear view mirror.
(2) Remove windshield wiper arms.
(3) Remove cowl cover.
(4) Remove A-pillar trim panels.
(5) Disconnect wire connectors to windshield
defroster grid.
RSSTATIONARY GLASS23 - 243

WEATHERSTRIP/SEALS
TABLE OF CONTENTS
page page
FRONT DOOR GLASS RUN WEATHERSTRIP
REMOVAL.............................248
INSTALLATION..........................248
FRONT DOOR OUTER BELT MOLDING
REMOVAL.............................249
INSTALLATION..........................249
FRONT DOOR WEATHERSTRIP
REMOVAL.............................249INSTALLATION..........................249
SLIDING DOOR WEATHERSTRIP
REMOVAL.............................249
INSTALLATION..........................249
FRONT DOOR INNER BELT MOLDING
REMOVAL.............................250
INSTALLATION..........................250
FRONT DOOR GLASS RUN
WEATHERSTRIP
REMOVAL
(1) Remove door frame closeout moldings.
(2) Pull weatherstrip from glass run channel at
rear of door frame, working from the bottom to the
top.
(3) Disengage clip attaching weatherstrip to door
frame.
(4) Pull weatherstrip from lip along top of door
frame (Fig. 1) .
(5) Remove door trim panel.
(6) Remove door speaker, if equipped.
(7) Remove watershed as necessary to gain access
to screw attaching front lower corner of glass run
weatherstrip to inner door panel.
(8) Remove screw attaching glass run weatherstrip
to inner door panel.
(9) Remove inner belt weatherstrip.
(10) Pull weatherstrip from front glass run chan-
nel.
(11) Remove glass run weatherstrip from vehicle.
INSTALLATION
(1) Position glass run weatherstrip on vehicle.
(2) Push weatherstrip into front glass run channel.
(3) Install screw attaching glass run weatherstrip
to inner door panel.
(4) Install inner belt weatherstrip.
(5) Install watershed.
(6) Push weatherstrip groove onto lip along top of
door frame.
(7) Engage clip into slot in door frame.(8) Push weatherstrip into channel at rear of door
frame, working from the top to bottom.
(9) Install door frame closeout moldings.
(10) Install door speaker, if equipped.
(11) Install door trim panel.
Fig. 1 Front Door Glass Run Weatherstrip
1 - DOOR GLASS RUN WEATHERSTRIP
2 - FRONT DOOR FRAME
3 - CLIP
4 - FRONT DOOR
23 - 248 WEATHERSTRIP/SEALSRS

FRONT DOOR OUTER BELT
MOLDING
REMOVAL
(1) Remove the side veiw mirror. (Refer to 23 -
BODY/EXTERIOR/SIDE VIEW MIRROR -
REMOVAL)
(2) Remove door trim panel.
(3) Roll door glass down.
(4) Using a hook tool, disengage interlocking lip at
the base of the inward edge of the belt molding (Fig.
2).
(5) Remove belt molding from door.
INSTALLATION
(1) Place belt molding in position on door.
(2) Engage interlocking lip at the base of the
inward edge of the belt molding on door panel.
(3) Install door trim panel.
FRONT DOOR WEATHERSTRIP
REMOVAL
(1) Open front door.
(2) Using fork tool (C-4829), remove push-in fas-
teners attaching front door weatherstrip to end
frames and bottom of door (Fig. 3) .(3) Pull weatherstrip from retaining channel
around window frame.
(4) Remove weatherstrip from vehicle.
INSTALLATION
For installation, reverse the above procedures.
SLIDING DOOR
WEATHERSTRIP
REMOVAL
(1) Open sliding door.
(2) Remove door opening sill plate.
(3) Loosen B-pillar trim covers.
(4) Loosen quarter panel trim panels.
(5) From splice at the bottom center of door open-
ing, pull weatherstrip from pinch flange around door
opening.
INSTALLATION
(1) Place splice at the bottom center of door open-
ing, pushing weatherstrip onto pinch flange around
door opening.
(2) Tighten quarter panel trim panels.
(3) Tighten B-pillar trim covers.
(4) Install door opening sill plate.
(5) Close sliding and check alignment.
Fig. 2 Front Door Outer Belt Molding
1 - OUTER BELT MOLDING
2 - FRONT DOOR
Fig. 3 Front Door Weatherstrip
1 - RETAINING CHANNEL
2 - PUSH-IN FASTENER
3 - WEATHERSTRIP
4 - FRONT DOOR
RSWEATHERSTRIP/SEALS23 - 249

DISTRIBUTION - FRONT
TABLE OF CONTENTS
page page
AIR FILTER
DESCRIPTION...........................41
REMOVAL..............................41
INSTALLATION...........................41
AIR OUTLETS
DESCRIPTION...........................42
REMOVAL..............................42
INSTALLATION...........................44
BLOWER MOTOR
DESCRIPTION...........................45
OPERATION.............................45
DIAGNOSIS AND TESTING.................45
BLOWER MOTOR......................45
REMOVAL..............................48
INSTALLATION...........................48DEFROSTER DUCT
REMOVAL..............................49
INSTALLATION...........................50
DEMISTER DUCTS
REMOVAL..............................50
INSTALLATION...........................50
FLOOR DISTRIBUTION DUCTS
REMOVAL..............................50
INSTALLATION...........................51
HVAC HOUSING
REMOVAL..............................51
INSTALLATION...........................52
PANEL DUCTS
REMOVAL..............................52
INSTALLATION...........................53
AIR FILTER
DESCRIPTION
A dust and odor air filter is standard equipment on
models equipped with the dual zone or three zone
temperature control systems (Fig. 1). The filter ele-
ment is the same size as the front air conditionerevaporator to ensure ample filtering capacity. A
removable door on the bottom of the front heater-A/C
unit housing below the glove box provides easy access
to the filter element for replacement. Filter replace-
ment is recommended at 24,000 kilometer (15,000
mile) intervals.
REMOVAL
(1) Locate the air filter door on the bottom of the
lower evaporator housing just outboard of the pas-
senger side of the instrument panel center stack (Fig.
2).
(2) Slide the air filter door latch toward the rear of
the vehicle until it engages the opened stop on the
door.
(3) Pull the air filter door straight downward to
disengage it from the air filter opening of the lower
evaporator housing.
(4) Use your fingers to reach through the air filter
opening of the lower evaporator housing far enough
to grasp the air filter.
(5) Pull the air filter straight down and out of the
evaporator housing (Fig. 1).
INSTALLATION
(1) Note the ªAirflowº directional arrow imprinted
on the foam seal around the frame of the air filter.
This arrow should always be oriented towards the
center of the vehicle.
(2) With the air filter ªAirflowº arrow properly ori-
ented, carefully slide the filter fully upward into the
evaporator housing through the air filter opening.
Fig. 1 Air Filter
1 - LOWER EVAPORATOR HOUSING
2 - LOWER EDGE OF INSTRUMENT PANEL
3 - AIR FILTER
4 - INSTRUMENT PANEL CENTER FLOOR BRACKET COVER
5 - FOAM SEAL
6 - AIR FILTER OPENING
RSDISTRIBUTION - FRONT24-41

(7) Remove the nut that secures the liquid line fit-
ting to the condenser on the right side of the cooling
module (Fig. 27).
(8) Disconnect the liquid line fitting from the con-
denser outlet port.
(9) Remove the seal from the liquid line fitting and
discard.
(10) Install plugs in, or tape over the opened liquid
line fitting and the condenser outlet port.(11) Disengage the retainer that secures the liquid
line routing clip to the top of the right frame rail
ahead of the front strut tower in the engine compart-
ment (Fig. 28).
(12) Remove the screw that secures the liquid line
front section fitting to the top of the filter-drier.
(13) Disconnect the liquid line fitting from the fil-
ter-drier inlet port.
(14) Remove the seal from the liquid line fitting
and discard.
(15) Install plugs in, or tape over the opened liquid
line fitting and the filter-drier inlet port.
(16) Remove the front section of the front liquid
line from the engine compartment.
REAR SECTION
(1) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - FRONT/REFRIGERANT -
Fig. 26 Radiator Sight Shield
1 - LARGE SCREWS (2)
2 - SMALL SCREWS (5)
3 - RADIATOR SIGHT SHIELD
4 - GRILLE INSERTS
5 - FRONT FASCIA
Fig. 27 Condenser Connections
1 - CONDENSER
2 - DISCHARGE LINE FITTING
3 - LIQUID LINE FITTING
4 - NUT
Fig. 28 Front Liquid Lines
1 - A/C GROUND STRAP
2 - NUT
3 - WELD STUD
4 - A/C PRESSURE TRANSDUCER
5 - WELD STUD (2)
6 - EXPANSION VALVE
7 - FRONT LIQUID LINE REAR SECTION
8 - LIQUID LINE EXTENSION (REAR A/C ONLY)
9 - NUT (2)
10 - FILTER-DRIER
11 - ROUTING CLIP
12 - FRONT LIQUID LINE FRONT SECTION
RSPLUMBING - FRONT24-83
LIQUID LINE (Continued)

STANDARD PROCEDURE - REFRIGERANT
RECOVERY).
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the air cleaner housing from the right
side of the engine compartment.
(4) Disconnect the drain tube from the wiper mod-
ule drain on the right side of the engine compart-
ment.
(5) Remove the A/C pressure transducer from the
fitting on the front liquid line rear section. (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS
- FRONT/A/C PRESSURE TRANSDUCER - REMOV-
AL).
(6) Remove the nut that secures the A/C ground
strap to the weld stud on the top of the right front
strut tower (Fig. 28).
(7) Remove the A/C ground strap eyelet terminal
connector from the weld stud.
(8) Remove the screw that secures the liquid line
rear section fitting to the top of the filter-drier.
(9) Disconnect the liquid line fitting from the fil-
ter-drier outlet port.
(10) Remove the seal from the liquid line fitting
and discard.
(11) Install plugs in, or tape over the opened liquid
line fitting and the filter-drier outlet port.
(12) Remove the nut that secures the suction line
and liquid line fittings to the expansion valve.
(13) Disconnect the suction line and liquid line fit-
tings from the expansion valve.
(14) Remove the seals from the suction line and
liquid line fittings and discard.
(15) Install plugs in, or tape over the opened suc-
tion line and liquid line fittings and both expansion
valve ports.
(16) If the vehicle is equipped with the optional
rear air conditioner, go to Step 17. If the vehicle does
not have the optional rear air conditioner, go to Step
23.
(17) Raise and support the vehicle.
(18) Cut the tie strap located just forward of the
connections between the underbody plumbing and
the engine compartment plumbing for the rear
heater and air conditioner (Fig. 29).
(19) Disconnect the front liquid line extension fit-
ting from the underbody liquid line fitting for the
rear air conditioner.
(20) Remove the seal from the underbody liquid
line fitting and discard.
(21) Install plugs in, or tape over the opened liquid
line fittings.
(22) Lower the vehicle.
(23) Remove the front liquid line rear section from
the engine compartment.
INSTALLATION
The front air conditioner liquid line is serviced in
two sections. The front section connects between the
condenser and the filter/drier and includes the high
side service port on the fitting for the filter/drier. The
rear section connects between the filter/drier and the
expansion valve and includes the fitting for the A/C
pressure transducer. On models equipped with the
optional rear air conditioner, the rear section of the
front air conditioner liquid line also includes a liquid
line hose and tube extension that connects the front
liquid line to the liquid line for the rear air condi-
tioner.
FRONT SECTION
(1) Position the front section of the front liquid
line into the engine compartment.
(2) Remove the tape or plugs from the liquid line
front section fitting for the filter-drier and the filter-
drier inlet port (Fig. 28).
(3) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the liquid line fitting.
(4) Reconnect the liquid line fitting to the filter-
drier inlet port on the top of the filter-drier.
(5) Install and tighten the screw that secures the
liquid line fitting to the filter-drier. Tighten the screw
to 2 N´m (16 in. lbs.).
(6) Engage the retainer that secures the liquid line
routing clip to the top of the right frame rail ahead of
the front strut tower in the engine compartment.
(7) Remove the tape or plugs from the condenser
outlet port and the liquid line fitting (Fig. 27).
Fig. 29 Underbody Connections
1 - SUCTION LINE EXTENSION
2 - LIQUID LINE EXTENSION
3 - TIE STRAP
4- HEATER LINE EXTENSIONS
5 - UNDERBODY LINES
24 - 84 PLUMBING - FRONTRS
LIQUID LINE (Continued)

put component, it can verify that the command was
carried out by monitoring specific input signals for
expected changes. For example, when the PCM com-
mands the Idle Air Control (IAC) Motor to a specific
position under certain operating conditions, it expects
to see a specific (target) idle speed (RPM). If it does
not, it stores a DTC.
PCM outputs monitored for functionality include:
²Fuel Injectors
²Ignition Coils
²Torque Converter Clutch Solenoid
²Idle Air Control
²Purge Solenoid
²EGR Solenoid
²LDP Solenoid
²Radiator Fan Control
²Trans Controls
OXYGEN SENSOR (O2S) MONITOR
DESCRIPTIONÐEffective 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 operating temperature 300É to 350ÉC
(572É to 662ÉF), the sensor generates a voltage that
is inversely proportional to the amount of oxygen in
the exhaust. When there is a large amount of oxygen
in the exhaust caused by a lean condition, the sensor
produces a low voltage, below 450 mV. When the oxy-
gen content is lower, caused by a rich condition, the
sensor produces a higher voltage, above 450mV.
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, Catalyst and Fuel Monitors.
The O2S may fail in any or all of the following
manners:
²Slow response rate (Big Slope)
²Reduced output voltage (Half Cycle)
²Heater Performance
Slow Response Rate (Big Slope)ÐResponse rate
is the time required for the sensor to switch from
lean to rich signal output once it is exposed to a
richer than optimum A/F mixture or vice versa. As
the PCM adjusts the air/fuel ratio, the sensor must
be able to rapidly detect the change. As the sensor
ages, it could take longer to detect the changes in the
oxygen content of the exhaust gas. The rate of
change that an oxygen sensor experiences is called
'Big Slope'. The PCM checks the oxygen sensor volt-
age in increments of a few milliseconds.Reduced Output Voltage (Half Cycle)ÐThe
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 concentrations
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. Each
time the voltage signal surpasses the threshold, a
counter is incremented by one. This is called the Half
Cycle Counter.
Heater PerformanceÐThe heater is tested by a
separate monitor. Refer to the Oxygen Sensor Heater
Monitor.
OPERATIONÐAs the Oxygen Sensor signal
switches, the PCM monitors the half cycle and big
slope signals from the oxygen sensor. If during the
test neither counter reaches a predetermined value, a
malfunction is entered and a Freeze Frame is stored.
Only one counter reaching its predetermined value is
needed for the monitor to pass.
The Oxygen Sensor Monitor is a two trip monitor
that is tested only once per trip. When the Oxygen
Sensor fails the test in two consecutive trips, the
MIL is illuminated and a DTC is set. The MIL is
extinguished when the Oxygen Sensor monitor
passes in three consecutive trips. The DTC is erased
from memory after 40 consecutive warm-up cycles
without test failure.
Enabling ConditionsÐThe following conditions
must typically be met for the PCM to run the oxygen
sensor monitor:
²Battery voltage
²Engine temperature
²Engine run time
²Engine run time at a predetermined speed
²Engine run time at a predetermined speed and
throttle opening
²Transmission in gear (automatic only)
²Fuel system in Closed Loop
²Long Term Adaptive (within parameters)
²Power Steering Switch in low PSI (no load)
²Engine at idle
²Fuel level above 15%
²Ambient air temperature
²Barometric pressure
²Engine RPM within acceptable range of desired
idle
²Closed throttle speed
Pending ConditionsÐThe Task Manager typi-
cally does not run the Oxygen Sensor Monitor if over-
lapping monitors are running or the MIL is
illuminated for any of the following:
²Misfire Monitor
²Front Oxygen Sensor and Heater Monitor
²MAP Sensor
25 - 2 EMISSIONS CONTROLRS
EMISSIONS CONTROL (Continued)