2002 CHRYSLER VOYAGER Ignition switch

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Fuel Injector No.3 BK At Fuel Injector N/S
Fuel Injector No.3 (Diesel) BK At Fuel Injector 11
Fuel Injector No.4 BK At Fuel Injector N/S
Fuel Injector No.4 (Diesel) BK At Fuel Injector 11
Fuel Injector No.5 BK At Fuel Injector N/S
Fuel Injector No.6 BK At Fuel Injector N/S
Fuel Pump Module LTGY Side of Fuel Tank N/S
Fuel Pressure Sensor (Diesel) BK Top Left of Engine 11
Generator BK Rear of Generator 10, 11, 13, 14
Glove Box Lamp BL Rear of Glove Box 18, 24
Glow Plug Relay (Diesel) BK Near Battery N/S
Halo Lamp WT Steering Column 15, 16, 17, 18, 26
Headlamp Switch BK Rear of Switch 15, 16, 25
Headlamp Washer Pump Motor At Motor N/S
High Note Horn BK Left Frame Rail 5
High Pressure Fuel Pump (Diesel) Rear of Pump 11
Hood Ajar Switch BK Left Fender 6
Idle Air Control Motor (2.4L) BK On Throttle Body 9
Idle Air Control Motor (3.3/3.8L) BK On Throttle Body 13
Ignition Coil Pack 2.4L BK Top of Valve Cover 9, 10
Ignition Coil Pack 3.3L, 3.8L DKGY Top of Engine 14
Ignition Switch BK Rear of Switch at Steering Column 15, 16, 17, 18, 26
Inlet Air Temperature Sensor BK Top Left of Engine N/S
Instrument Cluster BK Rear of Cluster 15, 16, 23
Instrument Panel Switch Bank BK Right Center of Instrument Panel 15, 18, 20
Instrument Panel Power Outlet NAT Center of Instrument Panel N/S
Integrated Power Module C1 LTGN Left Fender Shield 7
Integrated Power Module C2 GN/BL Left Fender Shield 7
Integrated Power Module C3
(Diesel)YL/RD Left Fender Shield 7
Integrated Power Module C3 (Gas) NAT/RD Left Fender Shield 7
Integrated Power Module C4 BL Left Fender Shield 7
Integrated Power Module C5 BK Left Fender Shield 7
Integrated Power Module C6 NAT Left Fender Shield 7
Integrated Power Module C7 BK/RD Left Fender Shield 7
Integrated Power Module C8 OR Left Fender Shield 7
Integrated Power Module C9 BK Left Fender Shield 7
Knock Sensor GY Front of Cylinder Block N/S
Leak Detection Pump LTGY At Pump 9, 10 14
Left B Pillar Switch GY Left B Pillar 34
Left Cinch/Release Motor GY Left Sliding Door N/S
Left Combination Relay BK Left Rear Quarter Panel N/S
RS8W-91 CONNECTOR/GROUND/SPLICE LOCATION8W-91-5
CONNECTOR/GROUND/SPLICE LOCATION (Continued)
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GROUNDS
GROUND NUMBER LOCATION FIG.
G100 Body Ground Near Powertrain Control Module N/S
G101 Above Starter 10
G102 Left Headlamp Area 1
G103 Above Starter 10
G200 Right Side of Instrument Panel 15, 19, 24
G201 Right Side of Instrument Panel 15, 19, 24
G202 Near Radio N/S
G300 Left B Pillar 27
G301 Right B Pillar 28, 33
G302 Left Rear Quarter N/S
G400 Liftgate Ground N/S
SPLICES
SPLICE NUMBER LOCATION FIG.
S101 800mm from T/O for G102 1
S102 500mm from T/O for G102 1
S103 (2.5L) Between T/O for Battery Temperature Sensor and T/O
for C10211
S103 (3.3L/3.8L) Near T/O for C100 N/S
S104 Near T/O for G102 1
S105 (3.3L/3.8L) Near T/O for Battery (+) N/S
S106 (2.4L) 40mm from T/O for Torque Converter Clutch Solenoid 10
S106 (2.5L) Near T/O for Battery Temperature Sensor 11
S106 (3.3L/3.8L) Near T/O for G103 14
S107 (2.4L) In T/O for EGR Solenoid 10
S107 (2.5L) Between T/O for Engine Starter Motor and T/O for
Engine Control Module C112
S107 (3.3L/3.8L) In T/O for EGR Solenoid 14
S108 (3.3L/3.8L) Near T/O for Powertrain Control Module N/S
S109 (3.3L/3.8L) Near T/O for Camshaft Position Sensor N/S
S110 Near T/O to G102 N/S
S111 (2.4L) Near T/O for C101 N/S
S111 (2.5L) Near T/O for Battery (-) N/S
S111 (3.3L/3.8L) Near T/O for Powertrain Control Module N/S
S112 Near T/O for Intelligent Power Module - C3 N/S
S113 (2.4L) Near T/O for Park/Neutral Position Switch N/S
S114 (3.3L/3.8L) In T/O to Transmission Control Module N/S
S115 (3.3L/3.8L) In T/O to Transmission Control Module N/S
S116 (2.4L) 180mm from T/O for Torque Converter Clutch Solenoid 10
S116 (2.5L) Near T/O for Mass Air Flow Sensor 12
S116 (3.3L/3.8L) Near T/O for Ignition Coil Pack 14
RS8W-91 CONNECTOR/GROUND/SPLICE LOCATION8W-91-11
CONNECTOR/GROUND/SPLICE LOCATION (Continued)
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SPECIAL TOOLS
POWER DISTRIBUTION SYSTEMS
ACCESSORY RELAY
DESCRIPTION
The accessory relay is an electromechanical device
that switches fused battery current to the accessory
powered vehicle circuits when the ignition switch is
turned to the Accessory or On positions. The delay
feature will maintain power to the accessories for 45
seconds after the ignition is shut off or until a door is
opened. This allows sufficient time to close windows
and park the windshield wipers. The accessory relay
is located in the Integrated Power Module (IPM) in
the engine compartment.
The accessory relay is a International Standards
Organization (ISO) relay. Relays conforming to the
ISO specifications have common physical dimensions,
current capacities, terminal patterns, and terminal
functions.
The accessory relay cannot be repaired or adjusted
and, if faulty or damaged, it must be replaced.
OPERATION
The ISO relay consists of an electromagnetic coil, a
resistor or diode, and three (two fixed and one movable)
electrical contacts. The movable (common feed) relay
contact is held against one of the fixed contacts (normal-
ly closed) by spring pressure. When the electromagnetic
coil is energized, it draws the movable contact away
from the normally closed fixed contact, and holds it
against the other (normally open) fixed contact.
When the electromagnetic coil is de-energized,
spring pressure returns the movable contact to the
normally closed position. The resistor or diode is con-
nected in parallel with the electromagnetic coil in the
relay, and helps to dissipate voltage spikes that are
produced when the coil is de-energized.
DIAGNOSIS AND TESTING
DIAGNOSIS & TESTING - ACCESSORY RELAY
The accessory relay (Fig. 1) is located in the Inte-
grated Power Module (IPM), in the engine compart-
ment. For complete circuit diagrams, refer toWiring
Diagrams.
(1) Remove the accessory relay from the IPM.
Refer toAccessory Relayin the Removal and
Installation section of this group for the procedure.
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   5 ohms. If OK, go to Step
4. If not OK, replace the faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, perform the Relay Circuit Test that
follows. If not OK, replace the faulty relay.
DIAGNOSIS & TESTING - RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) of
the IPM is connected to battery voltage and should
be hot at all times. Check for battery voltage at the
fused B(+) circuit cavity in the IPM receptacle for the
accessory relay. If OK, go to Step 2. If not OK, repair
the fused B(+) circuit to the IPM fuse as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in the de-energized position,
but is not used for this application. Go to Step 3.
(3) The relay normally open terminal (87) is con-
nected to the common feed terminal (30) in the ener-
gized position. This terminal supplies battery voltage
to the fused B(+) fuse in the IPM that feeds the
accessories when the relay is energized by the igni-
tion switch. There should be continuity between the
IPM cavity for relay terminal 87 and the fused B(+)
fuse in the IPM at all times. If OK, go to Step 4. If
not OK, repair the open fused B(+) circuit to the IPM
fuse as required.
Terminal Pick Kit 6680
Fig. 1 Accessory Relay
8W - 97 - 2 8W-97 POWER DISTRIBUTION SYSTEMRS
POWER DISTRIBUTION SYSTEM (Continued)
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(4) The coil ground terminal (85) is connected to
the electromagnet in the relay. It receives battery
feed to energize the accessory relay when the ignition
switch is in the Accessory or On positions. Turn the
ignition switch to the On position. Check for battery
voltage at the fused ignition switch output (acc/run)
circuit cavity for relay terminal 85 in the IPM recep-
tacle for the accessory relay. If OK, go to Step 5. If
not OK, repair the open fused ignition switch output
(acc/run) circuit to the ignition switch as required.
(5) The coil battery terminal (86) is connected to
the electromagnet in the relay. The IPM cavity for
this terminal should have continuity to ground at all
times. If not OK, repair the open ground circuit to
ground as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the Integrated Power Module (IPM)
cover from the IPM.
(3) Remove the accessory relay from the IPM.
Refer to the IPM cover for relay location.
INSTALLATION
(1) Position the accessory relay in the proper
receptacle in the Integrated Power Module (IPM).
(2) Push in firmly on the accessory relay until the
terminals are fully seated in the terminal cavities in
the IPM receptacle.
(3) Install the IPM cover.
(4) Reconnect the battery negative cable.
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 on this
model (Fig. 2). The power distribution center mates
directly with the Front Control Module (FCM) to
form the IPM Fuse and Relay Center. The power dis-
tribution center (PDC) is a printed circuit board
based module that contains fuses and relays, while
the front control module contains the electronics con-
trolling the IPM and other functions. This IPM con-
nects directly to the battery positive via a four pin
connector. The ground connection is via two other
connectors. The IPM provides the primary means of
voltage distribution and protection for the entire
vehicle.
The molded plastic IPM housing includes a base
and cover. The IPM cover is easily opened or removed
for service access by squeezing the two marked coverlatches and has a fuse and relay layout map integral
to the inside surface of the cover. This IPM housing
base and cover are secured in place by an IPM
mounting bracket. This mounting bracket is designed
to allow the IPM to rotate counter-clockwise once the
locking tab is disengaged. The IPM mounting bracket
is secured in place by bolts threaded into the left
front wheel house.
Replaceable components of the IPM assembly are
broken down into the following components: the
Power Distribution Center (PDC) (without fuses or
relays), the IPM cover, the Front Control Module
(FCM), the IPM mounting bracket, IPM bracket
retaining clips and the IPM assembly which includes
the power distribution center, the cover and FCM.
Refer to the Front Control Module in the Elec-
tronic Control Module sectionof this service
manual for information on the FCM.
OPERATION
All of the current from the battery and the gener-
ator output enters the Integrated Power Module
(IPM) via a four- pin connector on the bottom of the
module. The IPM cover is unlatched and opened or
removed to access the fuses or relays. Internal con-
nections of all of the power distribution center cir-
cuits is accomplished by a combination of bus bars
and a printed circuit board. Refer to the Wiring sec-
Fig. 2 BATTERY THERMAL GUARD
1 - BATTERY THERMAL GUARD
2 - INTEGRATED POWER MODULE
3 - FRONT CONTROL MODULE
RS8W-97 POWER DISTRIBUTION SYSTEM8W-97-3
ACCESSORY RELAY (Continued)
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tion. The IOD fuse is a 15 ampere blade-type car-
tridge 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) Remove the stored 15 amp IOD fuse from fuse
storage markedSPAREof the IPM.
(4) Use a thumb to press the IOD fuse firmly down
into IPM fuse cavity markedIOD.
(5) 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.
DIAGNOSIS AND TESTING
DIAGNOSIS & TESTING - POWER OUTLET
For complete circuit diagrams, refer toCigar
Lighter/Power Outletin Wiring Diagrams.
RS8W-97 POWER DISTRIBUTION SYSTEM8W-97-5
IOD FUSE (Continued)
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(3) Push the quick-connect fitting over the fuel
tube until theretainer seats and a click is heard.
(4) The plastic quick-connect fitting has windows
in the sides of the casing. When the fitting com-
pletely attaches to the fuel tube, the retainer locking
ears and the fuel tube shoulder are visible in the
windows. If they are not visible, the retainer was not
properly installed (Fig. 23).Do not rely upon the
audible click to confirm a secure connection.
(5) Connect negative cable to battery or auxiliary
jumper terminal.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) Relay remains energized
for several minutes, until the test is stopped, or
until the ignition switch is turned to the Off posi-
tion.
(6) Use the DRB IIItscan tool ASD Fuel System
Test to pressurize the fuel system. Check for leaks.
TWO-TAB TYPE FITTING
This type of fitting is equipped with tabs located on
both sides of the fitting (Fig. 24). These tabs are sup-
plied for disconnecting the quick-connect fitting from
component being serviced.
CAUTION: The interior components (O-rings, spac-
ers) of this type of quick-connect fitting are not ser-
viced separately, but new plastic retainers are
available. Do not attempt to repair damaged fittings
or fuel lines/tubes. If repair is necessary, replace
the complete fuel tube assembly.WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE (EVEN WITH THE ENGINE OFF).
BEFORE SERVICING ANY FUEL SYSTEM HOSES,
FITTINGS OR LINES, THE FUEL SYSTEM PRES-
SURE MUST BE RELEASED. REFER TO THE FUEL
PRESSURE RELEASE PROCEDURE IN THIS
GROUP.
DISCONNECTION/CONNECTION
(1) Perform fuel pressure release procedure. Refer
to Fuel Pressure Release Procedure in this group.
(2) Disconnect negative battery cable from battery
or auxiliary jumper terminal.
(3) Clean fitting of any foreign material before dis-
assembly.
(4) To disconnect quick-connect fitting, squeeze
plastic retainer tabs (Fig. 24) against sides of quick-
connect fitting with your fingers. Tool use is not
required for removal and may damage plastic
retainer. Pull fitting from fuel system component
being serviced. The plastic retainer will remain on
component being serviced after fitting is discon-
nected. The O-rings and spacer will remain in quick-
connect fitting connector body.
(5) Inspect quick-connect fitting body and compo-
nent for damage. Replace as necessary.
CAUTION: When the quick-connect fitting was dis-
connected, the plastic retainer will remain on the
component being serviced. If this retainer must be
removed, very carefully release the retainer from
the component with two small screwdrivers. After
removal, inspect the retainer for cracks or any dam-
age.
Fig. 23 Plastic Quick-Connect Fitting/Fuel Tube
Connection
1 - WINDOW
2-TAB(2)
3 - EAR
4 - SHOULDER (ON TUBE)
Fig. 24 Typical Two-Tab Type Quick-Connect Fitting
1 - TAB(S)
2 - QUICK-CONNECT FITTING
14 - 14 FUEL DELIVERYRS
QUICK CONNECT FITTING (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
RSFUEL INJECTION14-17
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1 second. Therefore, battery voltage is not supplied to
the fuel pump, ignition coil, fuel injectors and heated
oxygen sensors.
ENGINE START-UP MODE
This is an OPEN LOOP mode. If the vehicle is in
park or neutral (automatic transaxles) or the clutch
pedal is depressed (manual transaxles) the ignition
switch energizes the starter relay. The following
actions occur when the starter motor is engaged.
²If the PCM receives the camshaft position sensor
and crankshaft position sensor signals, it energizes
the Auto Shutdown (ASD) relay and fuel pump relay.
If the PCM does not receive both signals within
approximately one second, it will not energize the
ASD relay and fuel pump relay. The ASD and fuel
pump relays supply battery voltage to the fuel pump,
fuel injectors, ignition coil, (EGR solenoid and PCV
heater if equipped) and heated oxygen sensors.
²The PCM energizes the injectors (on the 69É
degree falling edge) for a calculated pulse width until
it determines crankshaft position from the camshaft
position sensor and crankshaft position sensor sig-
nals. The PCM determines crankshaft position within
1 engine revolution.
²After determining crankshaft position, the PCM
begins energizing the injectors in sequence. It adjusts
injector pulse width and controls injector synchroni-
zation by turning the individual ground paths to the
injectors On and Off.
²When the engine idles within  64 RPM of its
target RPM, the PCM compares current MAP sensor
value with the atmospheric pressure value received
during the Ignition Switch On (zero RPM) mode.
Once the ASD and fuel pump relays have been
energized, the PCM determines injector pulse width
based on the following:
²MAP
²Engine RPM
²Battery voltage
²Engine coolant temperature
²Inlet/Intake air temperature (IAT)
²Throttle position
²The number of engine revolutions since cranking
was initiated
During Start-up the PCM maintains ignition tim-
ing at 9É BTDC.
ENGINE WARM-UP MODE
This is an OPEN LOOP mode. The following inputs
are received by the PCM:
²Manifold Absolute Pressure (MAP)
²Crankshaft position (engine speed)
²Engine coolant temperature
²Inlet/Intake air temperature (IAT)
²Camshaft position²Knock sensor
²Throttle position
²A/C switch
²Battery voltage
²Vehicle speed
²Speed control
²O2 sensors
The PCM adjusts injector pulse width and controls
injector synchronization by turning the individual
ground paths to the injectors On and Off.
The PCM adjusts ignition timing and engine idle
speed. Engine idle speed is adjusted through the idle
air control motor.
CRUISE OR IDLE MODE
When the engine is at operating temperature this
is a CLOSED LOOP mode. During cruising or idle
the following inputs are received by the PCM:
²Manifold absolute pressure
²Crankshaft position (engine speed)
²Inlet/Intake air temperature
²Engine coolant temperature
²Camshaft position
²Knock sensor
²Throttle position
²Exhaust gas oxygen content
²A/C control positions
²Battery voltage
²Vehicle speed
The PCM adjusts injector pulse width and controls
injector synchronization by turning the individual
ground paths to the injectors On and Off.
The PCM adjusts engine idle speed and ignition
timing. The PCM adjusts the air/fuel ratio according
to the oxygen content in the exhaust gas (measured
by the upstream and downstream heated oxygen sen-
sor).
The PCM monitors for engine misfire. During
active misfire and depending on the severity, the
PCM either continuously illuminates or flashes the
malfunction indicator lamp (Check Engine light on
instrument panel). Also, the PCM stores an engine
misfire DTC in memory, if 2nd trip with fault.
The PCM performs several diagnostic routines.
They include:
²Oxygen sensor monitor
²Downstream heated oxygen sensor diagnostics
during open loop operation (except for shorted)
²Fuel system monitor
²EGR monitor (if equipped)
²Purge system monitor
²Catalyst efficiency monitor
²All inputs monitored for proper voltage range,
rationality.
²All monitored components (refer to the Emission
section for On-Board Diagnostics).
14 - 18 FUEL INJECTIONRS
FUEL INJECTION (Continued)
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