Fig. 7 INTEGRATED POWER MODULE
8W - 91 - 22 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONRS
CONNECTOR/GROUND/SPLICE LOCATION (Continued)
8W-97 POWER DISTRIBUTION SYSTEM
TABLE OF CONTENTS
page page
POWER DISTRIBUTION SYSTEM
DESCRIPTION..........................1
OPERATION............................1
SPECIAL TOOLS
POWER DISTRIBUTION SYSTEMS.........1
INTEGRATED POWER MODULE
DESCRIPTION..........................1
OPERATION............................2
REMOVAL.............................2
INSTALLATION..........................2IOD FUSE
DESCRIPTION..........................3
OPERATION............................3
POWER OUTLET
DESCRIPTION..........................3
OPERATION............................3
DIAGNOSIS AND TESTING
DIAGNOSIS & TESTING - POWER OUTLET . . 3
REMOVAL.............................4
INSTALLATION..........................4
POWER DISTRIBUTION
SYSTEM
DESCRIPTION
The power distribution system for this vehicle con-
sists of the following components:
²Integrated Power Module (IPM)
²Front Control Module (FCM)
²Power Outlets
Refer to Wiring Diagrams for complete circuit sche-
matics.
The power distribution system also incorporates
various types of circuit control and protection fea-
tures, including:
²Automatic resetting circuit breakers
²Blade-type fuses
²Bus bars
²Cartridge fuses
²Circuit splice blocks
²Flashers
²Fusible links
²Relays
OPERATION
The power distribution system for this vehicle is
designed to provide safe, reliable, and centralized dis-
tribution points for the electrical current required to
operate all of the many standard and optional facto-
ry-installed electrical and electronic powertrain,
chassis, safety, security, comfort and convenience sys-
tems. At the same time, the power distribution sys-
tem was designed to provide ready access to these
electrical distribution points for the vehicle techni-
cian to use when conducting diagnosis and repair of
faulty circuits. The power distribution system can
also prove useful for the sourcing of additional elec-
trical circuits that may be required to provide theelectrical current needed to operate many accessories
that the vehicle owner may choose to have installed.
SPECIAL TOOLS
POWER DISTRIBUTION SYSTEMS
INTEGRATED POWER MODULE
DESCRIPTION
The Integrated Power Module (IPM) is a combina-
tion of the Power Distribution Center (PDC) and the
Front Control Module (FCM). The IPM is located in
the engine compartment, next to the battery. (Fig. 1).
The PDC mates directly with the FCM to form the
IPM. The PDC is a printed circuit board based mod-
ule that contains fuses and relays, while the FCM
contains the electronics controlling the IPM and
other functions. This IPM connects directly to the
battery positive through a four pin connector. The
ground connection is through two other connectors.
Terminal Pick Kit 6680
RS8W-97 POWER DISTRIBUTION SYSTEM8W-97-1
The IPM provides the primary means of voltage dis-
tribution and protection for the entire vehicle.
OPERATION
All of the current from the battery and the gener-
ator output enters the Integrated Power Module
(IPM) through a four- pin connector on the bottom of
the module. Internal connections of all of the power
distribution center circuits is accomplished by a com-
bination of bus bars and a printed circuit board.
REMOVAL
(1) Disconnect the negative and positive battery
cables.
(2) Remove the battery thermal guard.
(3) Remove the battery (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/BATTERY - REMOVAL).
(4) Using a flat-bladed screwdriver, twist the Inte-
grated Power Module (IPM) bracket retaining latch
outward to free the IPM from its mounting bracket
(Fig. 2).
(5) Rotate the IPM counter-clockwise to access and
disconnect the electrical connectors (Fig. 3).
(6) Remove the IPM bracket clips from the hinge.
INSTALLATION
(1) Snap the left side of the Integrated Power Mod-
ule (IPM) housing in its mounting bracket and con-
nect the various electrical connectors.NOTE: Ensure that the Connector Positive Assur-
ance (CPA) on the five-pin B+ connector is posi-
tively engaged to prevent generating a Diagnostic
Trouble Code (DTC).
(2) Rotate the IPM clock-wise until secured in
mounting bracket. An audible click may be heard.
(3) Install the battery (Refer to 8 - ELECTRICAL/
BATTERY SYSTEM/BATTERY - INSTALLATION).
(4) Install the battery thermal guard.
Fig. 1 INTEGRATED POWER MODULE
1 - BATTERY THERMAL GUARD
2 - INTEGRATED POWER MODULE
3 - FRONT CONTROL MODULE
Fig. 2 INTEGRATED POWER MODULE
Fig. 3 DISCONNECTING IPM
1 - INTEGRATED POWER MODULE
8W - 97 - 2 8W-97 POWER DISTRIBUTION SYSTEMRS
INTEGRATED POWER MODULE (Continued)
(5) Connect the negative and positive battery
cables.
(6) Using a scan tool, check for any stored diagnos-
tic trouble codes. Ensure that all vehicle options are
operational.
IOD FUSE
DESCRIPTION
All vehicles are equipped with an Ignition-Off
Draw (IOD) fuse that is removed from its normal
cavity in the Integrated Power Module (IPM) when
the vehicle is shipped from the factory. Dealer per-
sonnel are to remove the IOD fuse from the storage
location and install it into the IPM fuse cavity
marked IOD as part of the preparation procedures
performed just prior to new vehicle delivery.
The IOD fuse is a 20 ampere blade-type mini fuse
and, when removed, it is stored in a fuse cavity adja-
cent to the washer fuse within the IPM.
OPERATION
The term ignition-off draw (IOD) identifies a nor-
mal condition 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 func-
tions for some of the electronic modules in the vehicle
as well as various other accessories that require bat-
tery current 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 opera-
tion so that the vehicle can be loaded, unloaded and
moved as needed by both vehicle transportation com-
pany and dealer personnel.
The IOD fuse is removed from the Integrated
Power Module (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 trans-
parent 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 service or diagnosis of any
vehicle system or condition, other than the same pur-
pose 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 approximately thirty days. However, it mustbe 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 thirty days,
the battery negative cable should be disconnected to
eliminate normal IOD; and, the battery should be
tested and recharged at regular intervals during the
vehicle storage period to prevent the battery from
becoming discharged or damaged.
POWER OUTLET
DESCRIPTION
Two power outlets are installed in the instrument
panel center lower bezel. Two additional power out-
lets are incorporated into the left rear C-pillar and
the center console (if equipped). The power outlets
bases are secured by a snap fit. A hinged plug flips
closed to conceal and protect the power outlet base
when not in use.
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.
DIAGNOSIS AND TESTING
DIAGNOSIS & TESTING - POWER OUTLET
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.
RS8W-97 POWER DISTRIBUTION SYSTEM8W-97-3
INTEGRATED POWER MODULE (Continued)
NOTE: Inspect crossover pipe fasteners for damage
from heat and corrosion. The cross-over bolts are
made of a special stainless steel alloy. If replace-
ment is required, OEM bolts are highly recom-
mended.
(3) Install the remaining manifold attaching bolts.
Tighten all bolts to 23 N´m (200 in. lbs.).
(4) Position the power steering pump support strut
and install upper bolt (Fig. 126).
(5) Install heat shield and attaching screws (Fig.
128).
(6) Install and connect upstream oxygen sensor
(Fig. 128).
(7) Raise the vehicle.
(8) Attach catalytic converter pipe to exhaust man-
ifold using new gasket and tighten bolts to 37 N´m
(27 ft. lbs.) (Fig. 127).
(9) Connect downstream oxygen sensor connector.
(10) Tighten the power steering pump support
strut lower bolt (Fig. 126).
(11) Install the belt splash shield and lower the
vehicle.
(12) Install the wiper module. (Refer to 8 - ELEC-
TRICAL/WIPERS/WASHERS/WIPER MODULE -
INSTALLATION)
(13) Connect battery negative cable.
EXHAUST MANIFOLD - LEFT
REMOVAL
(1) Disconnect battery negative cable.
(2) Remove bolts attaching crossover pipe to
exhaust manifold (Fig. 130).
(3) Disconnect left cylinder bank spark plug wires.(4) Remove heat shield attaching bolts (Fig. 131).
(5) Remove bolts attaching exhaust manifold to
cylinder head (Fig. 131).
(6) Remove the exhaust manifold (Fig. 131).
(7) Inspect and clean manifold. (Refer to 9 -
ENGINE/MANIFOLDS/EXHAUST MANIFOLD -
INSPECTION) (Refer to 9 - ENGINE/MANIFOLDS/
EXHAUST MANIFOLD - CLEANING)CLEANING
(1) Discard gasket (if equipped) and clean all sur-
faces of manifold and cylinder head.
Fig. 129 Check Exhaust Manifold Mounting
1 - STRAIGHT EDGE
2 - CROSSOVER PIPE MOUNTING SURFACE
3 - FEELER GAUGE
Fig. 130 CROSS-OVER PIPE
1 - CROSS-OVER PIPE
2 - BOLT
3 - GASKET
4 - FLAG NUT
Fig. 131 EXHAUST MANIFOLD - LEFT
1 - EXHAUST MANIFOLD - LEFT BANK
2 - HEAT SHIELD
3 - NUT - HEAT SHIELD
4 - BOLT - EXHAUST MANIFOLD
9 - 154 ENGINE 3.3/3.8LRS
EXHAUST MANIFOLD - RIGHT (Continued)
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 Powertrain Control Mod-
ule (PCM) controls the operation 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 DRBIIItscan 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. THIS MAY
RESULT IN PERSONAL INJURY OR DEATH.
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. Check the O-ring and make
sure that it is in place and not damaged. Attach end
of special test hose tool number 6539 at fuel line con-
nection from the body line. Position opposite end of
this hose tool to an approved gasoline draining sta-
tion. Activate fuel pump and drain tank until empty.
When done remove the special test hose tool number
6539 from the body line. Remove the plastic retainer
from the special test hose tool number 6539 and rein-
stall it into the fuel line from the body. Check the
O-ring and make sure that it is in place and not
damaged. 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.
14 - 2 FUEL DELIVERYRS
(6) Open fuel fill door and remove screws mount-
ing fuel filler tube assembly to body. Do not discon-
nect rubber fuel fill or vent hoses from tank at this
time.
(7) Place a transmission jack under center of fuel
tank. Apply a slight amount of pressure to fuel tank
with transmission jack.
(8) Remove fuel tank mounting straps.
(9)Lower the tank just enough so that the
filler tube fitting is the highest point of the fuel
tank.
(10) Remove filler tube from fuel tank. Tank will
be drained through this fitting.
NOTE: WRAP SHOP TOWELS AROUND HOSES TO
CATCH ANY GASOLINE SPILLAGE.
(11) Drain fuel tank into holding tank or a prop-
erly labeledGasolinesafety container.
WARNING: GASOLINE OR GASOLINE VAPORS ARE
HIGHLY FLAMMABLE. A FIRE COULD OCCUR IF AN
IGNITION SOURCE IS PRESENT. NEVER DRAIN OR
STORE GASOLINE OR DIESEL FUEL IN AN OPEN
CONTAINER, DUE TO THE POSSIBILITY OF FIRE
OR EXPLOSION. THIS MAY RESULT IN PERSONAL
INJURY OR DEATH.
(12) If fuel pump module removal is necessary,
refer to Fuel Pump Module Removal/Installation in
this section.
STANDARD PROCEDURE - FUEL PRESSURE
GAUGE
This gauge package (special tool #8974) (Fig. 1)is
designed to check the injectors or fuel pump for leak
down conditions and fuel system pressures. Refer to
the Powertrain Diagnostic Manual for more informa-
tion on the operation of this tool.
(1) Preform the fuel pressure release procedure,
refer to the Fuel Pressure release procedure in this
section.(2) Find a fuel line quick connect fitting that is
accessible and install special tool #8974.
(3) Refer to the Powertrain Diagnostic Manual for
the proper operation of this gauge package.
(4) Preform the fuel pressure release procedure,
refer to the Fuel Pressure release procedure in this
section.
(5) Remove gauge from fuel system and reconnect
fuel lines.
(6) Use the DRBIIItto pressurize the fuel system
to check for leaks
Fig. 1 FUEL SYSTEM PRESSURE TESTER #8978
1 - GAUGES
2 - HANGER
3 - RELEASE TOOL
4 - DRAIN HOSE
5 - DRAIN HOSE VALVE
6 - SHUT-OFF VALVE
RSFUEL DELIVERY14-3
FUEL DELIVERY (Continued)
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 - 22 FUEL INJECTIONRS