key CHRYSLER CARAVAN 2003 Repair Manual
[x] Cancel search | Manufacturer: CHRYSLER, Model Year: 2003, Model line: CARAVAN, Model: CHRYSLER CARAVAN 2003Pages: 2177, PDF Size: 59.81 MB
Page 1126 of 2177
CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Right Sliding Door Lock
Motor/Ajar SwitchBK At Latch N/S
Right Sliding Door Motor BK At Sliding Door 44
Right Speed Control Switch BK At Steering Wheel N/S
Right Stop/Turn Signal Relay BK LT Quarter Panel N/S
Right Turn Signal Lamp OR At Lamp N/S
Right Visor/Vanity Lamp BK At Lamp N/S
Sentry Key Immobilizer Module BK At Steering Column 19, 20, 21, 22, 30
Siren (United Kingdom) BK Left Front Body N/S
Solenoid/Pressure Switch
Assembly (EATX)BK Side of Transmission 14, 18
Speed Control Servo BK Near Controller Antilock Brake 11, 18
Sunroof Module BK At Sunroof N/S
Sunroof Switch Nat Near Overhead Console N/S
Thatcham Alarm Module C1 BK Top Right Side of Instrument Panel
Near SpeakerN/S
Thatcham Alarm Module C1 WT Top Right Side of Instrument Panel
Near SpeakerN/S
Throttle Position Sensor GY On Throttle Body 10, 11, 17
Torque Converter Clutch Solenoid BK Front of Transmission 11
Traction Control Switch BK Rear of Swtich 20, 21, 30
Trailer Tow Connector BK Left Quarter Panel N/S
Transmission Control Module BK Left Engine Compartment 5
Transmission Range Sensor GY Top of Transmission 14, 18
Turbo boost Pressure Sensor On Cylinder Block 15
Vehicle Speed Sensor BK Rear of Transmission 10, 16
Washer Fluid Level Switch BK Bottom of Reservoir 3
Water in Fuel Sensor (Diesel) Left Rear Engine Compartment N/S
Wiper Module BK Left Side Cowl 6
GROUNDS
GROUND NUMBER LOCATION FIG.
G100 Body Ground Near Powertrain Control Module N/S
G101 Above Starter 11, 13
G102 Left Headlamp Area 1
G103 Above Starter 11, 13
G200 Right Side of Instrument Panel 19, 23, 28
G201 Right Side of Instrument Panel 19, 23, 28
G202 Near Radio N/S
G300 Left B Pillar 31
G301 Right B Pillar 32, 38
G302 Left Rear Quarter 46
G400 Liftgate Ground N/S
RS8W-91 CONNECTOR/GROUND/SPLICE LOCATION8W-91-11
CONNECTOR/GROUND/SPLICE LOCATION (Continued)
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Page 1178 of 2177
The IPM has a molded plastic cover that can be
removed to provide service access to all of the fuses
and relays in the IPM. An integral latch and hinges
are molded into the IPM cover for easy removal. A
fuse layout map is integral to the underside of the
IPM cover to ensure proper fuse and relay identifica-
tion. The IOD fuse is a 20 ampere blade-type mini
fuse and, when removed, it is stored in a fuse cavity
adjacent to the washer fuse within the IPM.
OPERATION
The term ignition-off draw identifies a normal con-
dition where power is being drained from the battery
with the ignition switch in the Off position. The IOD
fuse feeds the memory and sleep mode functions for
some of the electronic modules in the vehicle as well
as various other accessories that require battery cur-
rent when the ignition switch is in the Off position,
including the clock. The only reason the IOD fuse is
removed is to reduce the normal IOD of the vehicle
electrical system during new vehicle transportation
and pre-delivery storage to reduce battery depletion,
while still allowing vehicle operation so that the
vehicle can be loaded, unloaded and moved as needed
by both vehicle transportation company and dealer
personnel.
The IOD fuse is removed from the IPM fuse cavity
when the vehicle is shipped from the assembly plant.
Dealer personnel must install the IOD fuse when the
vehicle is being prepared for delivery in order to
restore full electrical system operation. Once the
vehicle is prepared for delivery, the IOD function of
this fuse becomes transparent and the fuse that has
been assigned the IOD designation becomes only
another Fused B(+) circuit fuse. The IOD fuse serves
no useful purpose to the dealer technician in the ser-
vice or diagnosis of any vehicle system or condition,
other than the same purpose as that of any other
standard circuit protection device.
The IOD fuse can be used by the vehicle owner as
a convenient means of reducing battery depletion
when a vehicle is to be stored for periods not to
exceed about thirty days. However, it must be
remembered that removing the IOD fuse will not
eliminate IOD, but only reduce this normal condition.
If a vehicle will be stored for more than about thirty
days, the battery negative cable should be discon-
nected to eliminate normal IOD; and, the battery
should be tested and recharged at regular intervals
during the vehicle storage period to prevent the bat-
tery from becoming discharged or damaged. Refer to
Battery Systemfor additional service information.
REMOVAL
(1) Turn the ignition switch to the Off position.(2) Unlatch and open the cover of the intelligent
power module.
(3) Remove the IOD fuse from fuse location
markedIODof the Integrated Power Module (IPM).
(4) Store the removed IOD fuse by installing it in
the unused fuse storage markedSPAREof the IPM.
(5) Close and latch the IPM.
INSTALLATION
(1) Be certain the ignition switch is in the Off posi-
tion.
(2) Unlatch and open the cover of the Integrated
Power Module (IPM).
(3) Use a thumb to press the IOD fuse firmly down
into IPM fuse cavity markedIOD.
(4) Close and latch the IPM cover.
POWER OUTLET
DESCRIPTION
Accessory power outlets are standard equipment on
this model. Two power outlets are installed in the
instrument panel center lower bezel, which is located
near the bottom of the instrument panel center stack
area. Two additional power outlets are also incorpo-
rated into the vehicle, one on the left rear C-pillar
trim and the other in the center console, if equipped.
The power outlets bases are secured by a snap fit in
the appropriate bezels. A hinged plug flips closed to
conceal and protect the power outlet base when the
power outlet is not being used.
The power outlet receptacle unit and the power
outlet plugs are each available for service replace-
ment.
OPERATION
The power outlet base or receptacle shell is con-
nected to ground, and an insulated contact in the
bottom of the shell is connected to battery current.
The power outlet on the instrument panel marked
with a battery receives battery voltage from a fuse in
the Integrated Power Module (IPM) at all times. The
other power outlet on the instrument panel marked
with a key receives battery voltage only when the
key is in the on position.
The power outlet located in the center console
receives battery voltage all the time when positioned
between thefront seatsand key-on voltage when
positioned between therear seats. The power outlet
located on the C-pillar receives battery voltage only
when the key is in the on position.
RS8W-97 POWER DISTRIBUTION SYSTEM8W-97-5
IOD FUSE (Continued)
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DIAGNOSIS AND TESTING
DIAGNOSIS & TESTING - POWER OUTLET
For complete circuit diagrams, refer toCigar
Lighter/Power Outletin Wiring Diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO RESTRAINTS BEFORE ATTEMPT-
ING ANY STEERING WHEEL, STEERING COLUMN,
SEAT OR INSTRUMENT PANEL COMPONENT DIAG-
NOSIS OR SERVICE. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Check the fused B(+) fuse in the Integrated
Power Module (IPM). If OK, go to Step 2. If not OK,
repair the shorted circuit or component as required
and replace the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the IPM. If OK, go to Step 3. If not OK, repair the
open fused B(+) circuit to the IPM fuse as required.
(3)
Open the power outlet door. Check for continuity
between the inside circumference of the power outlet
receptacle and a good ground. There should be continu-
ity. If OK, go to Step 4. If not OK, go to Step 5.
(4) Check for battery voltage at the insulated con-
tact located at the back of the power outlet recepta-
cle. If not OK, go to Step 5.
(5) Disconnect and isolate the battery negative
cable. Remove the appropriate bezel. Check for conti-
nuity between the ground circuit cavity of the power
outlet wire harness connector and a good ground.
There should be continuity. If OK, go to Step 6. If not
OK, repair the open ground circuit to ground as
required.
(6) Connect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
power outlet wire harness connector. If OK, replace
the faulty power outlet receptacle. If not OK, repair
the open fused B(+) circuit to the IPM fuse as
required.
REMOVAL
(1)Disconnect and isolate the battery negative cable.
(2) Look inside and note position of the retaining
bosses (Fig. 5).
(3) Using external snap ring pliers with 90 degree
tips. Insert pliers with tips against bosses and
squeeze forcing bosses out of base.
(4) Pull out the base through mounting ring by
gently rocking pliers. A tool can be made to do the
same. Refer to (Fig. 6).
(5) Disconnect the base wires.
(6) Set base aside. Remove light ring and discon-
nect wire.
INSTALLATION
(1) Position the mounting ring on the instrument
panel and feed the wires through the ring. Index the
cap and the mounting ring with the index tab at the
9 o'clock position to the key in the instrument panel.
Install the ring.
(2) Connect the wires to the base. Orientate the
base alignment rib at the 11 o'clock position to mate
the groove in the mounting ring to the base.
(3)
Push the base into the bezel until it locks in place.
(4) Check operation of outlet or element and
install the 12 volt outlet cap.
Fig. 5 Outlet Base Removal
1 - RETAINING BOSSES-ENGAGE PLIERS HERE
2 - PARTIALLY REMOVED
3 - EXTERNAL SNAP-RING PLIERS
4 - PULL BASE OUT-THROUGH MOUNTING RING
Fig. 6 Tool For Outlet Removal
1 - 2.5MM (3/32 INS.)
2 - WELD
3 - 100MM (4 INS.)
4 - 22.25 TO 22.45MM (7/8 TO 57/64 INS.)
8W - 97 - 6 8W-97 POWER DISTRIBUTION SYSTEMRS
POWER OUTLET (Continued)
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Page 1234 of 2177
OIL PUMP
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove timing belt (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT AND SPROCKETS -
REMOVAL).
(3) Remove timing belt rear cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT COVER(S)
- REMOVAL).
(4) Remove oil pan (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - REMOVAL).
(5) Remove crankshaft sprocket using Special
Tools 6793 and C-4685-C2 (Fig. 90).
(6) Remove crankshaft key (Fig. 91).
(7) Remove oil pick-up tube.(8) Remove oil pump (Fig. 92) and front crankshaft
seal.
DISASSEMBLY
(1) To remove the relief valve, proceed as follows:
(a) Remove the threaded plug and gasket from
the oil pump (Fig. 93) .
(b) Remove spring and relief valve (Fig. 93) .
Fig. 90 Crankshaft Sprocket - Removal
1 - SPECIAL TOOL 6793
2 - SPECIAL TOOL C-4685±C2
3 - CRANKSHAFT SPROCKET
Fig. 91 Crankshaft Key
1 - CRANKSHAFT KEY
Fig. 92 Oil Pump
1 - BOLTS
2 - BOLTS
3 - OIL PUMP
Fig. 93 Oil Pressure Relief Valve
1 - PLUG
2 - OIL PUMP BODY
3 - RELIEF VALVE
4 - SPRING
5 - SEAL
RSENGINE 2.4L9-55
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Page 1236 of 2177
CAUTION: Oil pump pressure relief valve must be
installed as shown in (Fig. 93) or serious engine
damage may occur.
(4) Install relief valve, spring, gasket and cap as
shown in (Fig. 93). Tighten cap to 41 N´m (30 ft.
lbs.).
INSTALLATION
(1) Make sure all surfaces are clean and free of oil
and dirt.
(2) Apply MopartGasket Maker to oil pump as
shown in (Fig. 98). Install O-ring into oil pump body
discharge passage.
(3) Prime oil pump with engine oil before installa-
tion.
(4) Align oil pump rotor flats with flats on crank-
shaft. Install the oil pump to the block (Fig. 92).
CAUTION: To align, the front crankshaft seal MUST
be out of pump, or damage may result.
(5) Install new front crankshaft seal using Special
Tool 6780 (Fig. 99).
(6) Install crankshaft key (Fig. 91).
CAUTION: The crankshaft sprocket is set to a pre-
determined depth from the factory for correct tim-
ing belt tracking. If removed, use of Special Tool
6792 is required to set the sprocket to original
installation depth. An incorrectly installed sprocket
will result in timing belt and engine damage.
(7) Install crankshaft sprocket using Special Tool
6792 (Fig. 100).
(8) Install oil pump pick-up tube.
(9) Install oil pan (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - INSTALLATION).(10) Install timing belt rear cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT COVER(S)
- INSTALLATION).
(11) Install timing belt (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT AND SPROCKETS -
INSTALLATION).
Fig. 98 Oil Pump Sealing
1 - O-RING
2 - SEALER LOCATION
Fig. 99 Front Crankshaft Seal - Installation
1 - PROTECTOR
2 - SEAL
3 - SPECIAL TOOL 6780
Fig. 100 Crankshaft Sprocket - Installation
1 - SPECIAL TOOL 6792
2 - TIGHTEN NUT TO INSTALL
RSENGINE 2.4L9-57
OIL PUMP (Continued)
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Page 1251 of 2177
INSTALLATION
BALANCE SHAFT INSTALLATION/TIMING
Balance shaft and carrier assembly installation is
the reverse of the removal procedure.During instal-
lation crankshaft-to-balance shaft timing must
be established. Refer to Timing procedure in
this section.
(1) With balance shafts installed in carrier (Fig.
130) position carrier on crankcase and install four
attaching bolts and tighten to 54 N´m (40 ft. lbs.).
(2) Turn balance shafts until both shaft key ways
are up, parallel to vertical centerline of engine.
Install short hub drive gear on sprocket driven shaft
and long hub gear on gear driven shaft. After instal-
lation gear and balance shaft keyways must be up
with gear timing marks meshed as shown in (Fig.
135).
(3) Install gear cover and tighten double ended
stud/washer fastener to 12 N´m (105 in. lbs.).
(4) Align flat on balance shaft drive sprocket to the
flat on crankshaft (Fig. 136).
(5) Install balance shaft drive sprocket on crank-
shaft using Special Tool 6052 (Fig. 137).
(6) Turn crankshaft until number 1 cylinder is at
top dead center (TDC). The timing marks on the
chain sprocket should line up with the parting line
on the left side of number one main bearing cap.
(Fig. 138).
(7) Place chain over crankshaft sprocket so that
the plated link of the chain is over the number 1 cyl-
inder timing mark on the balance shaft crankshaft
sprocket (Fig. 138).
(8) Place balance shaft sprocket into the timing
chain (Fig. 138) and align the timing mark on the
sprocket (dot) with the (lower) plated link on the
chain.NOTE: The lower plated link is 8 links from the
upper link.
Fig. 135 Gear Timing
1 - KEY WAYS UP
2 - GEAR ALIGNMENT DOTS
Fig. 136 Balance Shaft Sprocket Alignment to
Crankshaft
1 - ALIGN FLATS
Fig. 137 Balance Shaft Drive
1 - SPROCKET
2 - SPECIAL TOOL 6052
9 - 72 ENGINE 2.4LRS
BALANCE SHAFTS AND CARRIER ASSEMBLY (Continued)
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Page 1252 of 2177
(9) With balance shaft keyways pointing up (12
o'clock) slide the balance shaft sprocket onto the nose
of the balance shaft. The balance shaft may have to
be pushed in slightly to allow for clearance.
NOTE: THE TIMING MARK ON THE SPROCKET, THE
(LOWER) NICKEL PLATED LINK, AND THE ARROW
ON THE SIDE OF THE GEAR COVER SHOULD LINE
UP WHEN THE BALANCE SHAFTS ARE TIMED
CORRECTLY.
(10) If the sprockets are timed correctly, install the
balance shaft bolts and tighten to 28 N´m (250 in.
lbs.). A wood block placed between crankcase and
crankshaft counterbalance will prevent crankshaft
and gear rotation.(11)CHAIN TENSIONING:
(a) Install chain tensioner loosely assembled.
(b) Position guide on double ended stud making
sure tab on the guide fits into slot on the gear
cover. Install and tighten nut/washer assembly to
12 N´m (105 in. lbs.).
(c) Place a shim 1 mm (0.039 in.) thick x 70 mm
(2.75 in.) long between tensioner and chain. Push
tensioner and shim up against the chain.Apply
firm pressure 2.5±3 Kg (5.5±6.6 lbs.) directly
behind the adjustment slot to take up all
slack.Chain must have shoe radius contact as
shown in (Fig. 139).
(d) With the load applied, tighten top tensioner
bolt first, then bottom pivot bolt. Tighten bolts to
12 N´m (105 in. lbs.). Remove shim.
(e) Install carrier covers and tighten screws to
12 N´m (105 in. lbs.).
(12) If removed, install oil pump (Refer to 9 -
ENGINE/LUBRICATION/OIL PUMP - INSTALLA-
TION).
(13) Install pick-up tube and oil pan (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
(14) Fill engine crankcase with proper oil to cor-
rect level.
Fig. 138 Balance Shaft Timing
1 - MARK ON SPROCKET
2 - KEYWAYS UP
3 - ALIGN MARKS
4 - PLATED LINK
5 - PARTING LINE (BEDPLATE TO BLOCK)
6 - PLATED LINK
Fig. 139 Chain Tension Adjustment
1 - 1MM (0.039 IN.) SHIM
2 - TENSIONER (ADJUSTER) BOLT
3 - PIVOT BOLT
RSENGINE 2.4L9-73
BALANCE SHAFTS AND CARRIER ASSEMBLY (Continued)
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Page 1361 of 2177
FUEL DELIVERY
DESCRIPTION
DESCRIPTION
The front wheel drive car uses a plastic fuel tank
located rear center of the vehicle.
The Fuel Delivery System consists of: the following
items:
²Electric fuel pump module
²Fuel filter
²Tubes/lines/hoses
²Fuel injectors
The in-tank fuel pump module contains the fuel
pump. The pump is serviced as part of the fuel pump
module. Refer to Fuel Pump Module.
The fuel filter is replaceable only as part of the
fuel pump module.
DESCRIPTION - FFV REPLACEMENT PARTS
Many components in a Flexible Fuel Vehicle (FFV)
are designed to be compatible with ethanol. Always
be sure that the vehicle is serviced with correct etha-
nol compatible parts.
CAUTION: Replacing fuel system components with
non-ethanol compatible components can damage
your vehicle and may void the warranty.
OPERATION
The fuel system provides fuel pressure by an
in-tank pump module. The PCM controls the opera-
tion of the fuel system by providing battery voltage
to the fuel pump through the fuel pump relay. The
PCM requires only three inputs and a good ground to
operate the fuel pump relay. The three inputs are:
²Ignition voltage
²Crankshaft Position (CKP) sensor
²Camshaft Position (CMP) sensor
DIAGNOSIS AND TESTING - FUEL DELIVERY
SYSTEM
(Refer to Appropriate Diagnostic Information)
STANDARD PROCEDURE
STANDARD PROCEDURE - FUEL SYSTEM
PRESSURE RELEASE PROCEDURE
(1) Remove Fuel Pump relay from Power Distribu-
tion Center (PDC). For location of relay, refer to label
on underside of PDC cover.
(2) Start and run engine until it stalls.(3) Attempt restarting engine until it will no
longer run.
(4) Turn ignition key to OFF position.
(5) Return fuel pump relay to PDC.
(6) One or more Diagnostic Trouble Codes (DTC's)
may have been stored in PCM memory due to fuel
pump relay removal. The DRB IIItscan tool must be
used to erase a DTC.
STANDARD PROCEDURE - DRAINING FUEL
TANK
Two different procedures may be used to drain fuel
tank (lowering tank or using DRB scan tool).
The quickest draining procedure involves lowering
the fuel tank.
WARNING: RELEASE FUEL SYSTEM PRESSURE
BEFORE SERVICING FUEL SYSTEM COMPONENTS.
SERVICE VEHICLES IN WELL VENTILATED AREAS
AND AVOID IGNITION SOURCES. NEVER SMOKE
WHILE SERVICING THE VEHICLE.
As an alternative procedure, the electric fuel pump
may be activated allowing tank to be drained at fuel
rail connection. Refer to DRBIIItscan tool for fuel
pump activation procedures. Before disconnecting
fuel line at fuel rail, release fuel pressure. Refer to
the Fuel System Pressure Release Procedure in this
group for procedures. Disconnect the fuel line at the
fuel rail and remove the plastic retainer from the
fuel rail. Take plastic retainer and install it back into
the fuel line from body. Attach end of special test
hose tool number 8978 at fuel line connection from
the body line. Position opposite end of this hose tool
to an approved gasoline draining station. Activate
fuel pump and drain tank until empty. When done
remove the special test hose tool number 8978 from
the body line. Remove the plastic retainer from the
special test hose tool number 8978 and reinstall it
into the fuel line from the body. Install the fuel line
to the fuel rail.
If electric fuel pump is not operating, tank must be
lowered for fuel draining. Refer to following proce-
dures.
(1) Remove fuel filler cap.
(2) Perform the Fuel System Pressure Release pro-
cedure.
(3) Disconnect negative cable from battery.
(4) Raise vehicle and support.
(5) Certain models are equipped with a separate
grounding wire (strap) connecting the fuel fill tube
assembly to the body. Disconnect wire by removing
screw.
(6) Open fuel fill door and remove screws mount-
ing fuel filler tube assembly to body. Do not discon-
14 - 2 FUEL DELIVERYRS
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Page 1377 of 2177
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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Page 1390 of 2177
metric goes down. The first thing that happens as
the key is rolled on, before reaching the crank posi-
tion, the PCM powers up, comes around and looks at
the MAP voltage, and based upon the voltage it sees,
it knows the current barometric pressure relative to
altitude. Once the engine starts, the PCM looks at
the voltage again, continuously every 12 milliseconds,
and compares the current voltage to what it was at
key on. The difference between current and what it
was at key on is manifold vacuum.
During key On (engine not running) the sensor
reads (updates) barometric pressure. A normal range
can be obtained by monitoring known good sensor in
you work area.
As the altitude increases the air becomes thinner
(less oxygen). If a vehicle is started and driven to a
very different altitude than where it was at key On
the barometric pressure needs to be updated. Any
time the PCM sees Wide Open throttle, based upon
TPS angle and RPM it will update barometric pres-
sure in the MAP memory cell. With periodic updates,
the PCM can make its calculations more effectively.
The PCM uses the MAP sensor to aid in calculat-
ing the following:
²Barometric pressure
²Engine load
²Manifold pressure
²Injector pulse-width
²Spark-advance programs
²Shift-point strategies (F4AC1 transmissions
only, via the PCI bus)
²Idle speed
²Decel fuel shutoff
The PCM recognizes a decrease in manifold pres-
sure by monitoring a decrease in voltage from the
reading stored in the barometric pressure memory
cell. The MAP sensor is a linear sensor; as pressure
changes, voltage changes proportionately. The range
of voltage output from the sensor is usually between
4.6 volts at sea level to as low as 0.3 volts at 26 in. of
Hg. Barometric pressure is the pressure exerted by
the atmosphere upon an object. At sea level on a
standard day, no storm, barometric pressure is 29.92
in Hg. For every 100 feet of altitude barometric pres-
sure drops .10 in. Hg. If a storm goes through it can
either add, high pressure, or decrease, low pressure,
from what should be present for that altitude. You
should make a habit of knowing what the average
pressure and corresponding barometric pressure is
for your area.
REMOVAL
REMOVAL - 2.4L
(1) Disconnect the negative battery cable.(2) Disconnect electrical connector and vacuum
hose from MAP sensor (Fig. 20).
(3) Remove two screws holding sensor to the
intake manifold.
REMOVAL - 3.3/3.8L
(1) Disconnect the negative battery cable.
(2) Remove vacuum hose and mounting screws
from manifold absolute pressure (MAP) sensor (Fig.
21).
(3) Disconnect electrical connector from sensor.
Remove sensor.
INSTALLATION
INSTALLATION - 2.4L
(1) Install sensor.
(2) Install two screws and tighten.
(3) Connect the electrical connector and vacuum
hose to the MAP sensor (Fig. 20).
(4) Connect the negative battery cable.
INSTALLATION - 3.3/3.8L
(1) Install sensor (Fig. 21).
(2) Install screws and tighten toPLASTIC MAN-
IFOLD 1.7 N´m (15 in. lbs.) ALUMINUM MANI-
FOLD 3.3 N´m (30 in. lbs.).
(3) Connect the electrical connector to the sensor.
Install vacuum hose.
(4) Connect the negative battery cable.
O2 SENSOR
DESCRIPTION
The upstream oxygen sensor threads into the out-
let flange of the exhaust manifold (Fig. 22) or (Fig.
23).
The downstream heated oxygen sensor threads into
the outlet pipe at the rear of the catalytic convertor
(Fig. 24).
OPERATION
For SBEC vehicles a single sensor ground is used
for all 4 O2 sensors (6 Cyl.). A seperate upstream and
downstream grounds are used on the NGC vehicles
(4 Cyl.).
As vehicles accumulate mileage, the catalytic con-
vertor deteriorates. The deterioration results in a
less efficient catalyst. To monitor catalytic convertor
deterioration, the fuel injection system uses two
heated oxygen sensors. One sensor upstream of the
catalytic convertor, one downstream of the convertor.
The PCM compares the reading from the sensors to
calculate the catalytic convertor oxygen storage
RSFUEL INJECTION14-31
MAP SENSOR (Continued)
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