1995 JEEP YJ oil pressure

SIDE CLEARANCE MEASUREMENT
Slide snug-fitting feeler gauge between the connect-
ing rod and crankshaft journal flange. Refer to En-
gine Specifications for the proper clearance. Replace
the connecting rod if the side clearance is not within
specification.
PISTON FITTING
BORE GAUGE METHOD
(1) To correctly select the proper size piston, a cyl-
inder bore gauge, Special Tool 6879 or equivalent, ca-
pable of reading in .00019INCREMENTS with gauge
ring Special Tool 6884 is required. If a bore gauge is
not available, do not use an inside micrometer.
(2) Set the bore gauge to the gauge ring and zero
gauge.
(3) Remove gauge from ring and check cylinder as
shown in (Fig. 8) bore and record reading.
(4) Measure the inside diameter of the cylinder
bore at a point 58.725 mm (2-5/16 inches) below top
of bore. Start perpendicular (across or at 90 degrees)
to the axis of the crankshaft at point B and then take
an additional bore reading 90 degrees to that at point A.
(5) Recheck bore gauge in gauge ring, bore gauge
should read zero. If gauge does not read zero, reset
gauge and start over with procedure.
The coated pistons will be serviced with the piston
pin and connecting rod pre-assembled.The coated
piston connecting rod assembly can be used to
service previous built engines and MUST be re-
placed as complete sets.Tin coated pistons should
not be used as replacements for the new coated pistons.
The coating material is applied to the piston after
the final piston machining process. Measuring the
outside diameter of a coated piston will not provide
accurate results. Therefore, measuring the inside di-
ameter of the cylinder bore with a dial Bore Gauge is
MANDATORY. To correctly select the proper sizepiston, a cylinder bore gauge capable of reading
.00019increments is required.
Piston installation into the cylinder bore requires
slightly more pressure than that required for non-
coated pistons. The bonded coating on the piston will
give the appearance of a line-to-line fit with the cyl-
inder bore.
PISTON PIN
Piston pins are press-fitted into the connecting rods
and require no locking device. The piston, piston pin
and connecting rod are replaced as an assembly.
PISTON RING FITTING
(1) Carefully clean the carbon from all ring
grooves. Oil drain openings in the oil ring groove and
pin boss must be clear. DO NOT remove metal from
the grooves or lands. This will change ring-to-groove
clearances and will damage the ring-to-land seating.
(2) Be sure the piston ring grooves are free of nicks
and burrs.
(3) Measure the ring side clearance with a feeler
gauge fitted snugly between the ring land and ring
(Fig. 11). Rotate the ring in the groove. It must move
freely around circumference of the groove.
(4) Place ring in the cylinder bore and push down
with inverted piston to position near lower end of the
ring travel. Measure ring gap with a feeler gauge fit-
ting snugly between ring ends (Fig. 12). The correct
compression ring end gap is 0.25-0.51 mm (0.010-
0.020 inch). The correct oil control ring end gap is
0.381-1.397 mm (0.015-0.055 inch).
Fig. 8 Bore Gauge
Fig. 9 Piston Size Chart
Fig. 10 Piston Dimensions
9 - 84 4.0L ENGINEJ

(8) Lower the vehicle.
(9) Install the engine cylinder head, push rods,
rocker arms, bridges, pivots and engine cylinder head
cover.
(10) Fill the crankcase with engine oil.
CRANKSHAFT MAIN BEARINGS
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the spark plugs.
(3) Raise the vehicle.
(4) Remove the oil pan and oil pump.
(5) Remove only one main bearing cap and lower
insert at a time (Fig. 1).
(6) Remove the lower insert from the bearing cap.
(7) Remove the upper insert by LOOSENING (DO
NOT REMOVE) all of the other bearing caps. Now
insert a small cotter pin tool in the crankshaft jour-
nal oil hole. Bend the cotter pin as illustrated to fab-
ricate the tool (Fig. 2). With the cotter pin tool in
place, rotate the crankshaft so that the upper bear-
ing insert will rotate in the direction of its locking
tab. Because there is no hole in the No.3 main jour-
nal, use a tongue depressor or similar soft-faced tool
to remove the bearing insert (Fig. 2). After moving
the insert approximately 25 mm (1 inch), it can be
removed by applying pressure under the tab.
(8) Using the same procedure described above, re-
move the remaining bearing inserts one at a time for
inspection.
INSPECTION
Wipe the inserts clean and inspect for abnormal
wear patterns and for metal or other foreign material
imbedded in the lining. Normal main bearing insert
wear patterns are illustrated (Fig. 3).
If any of the crankshaft journals are scored,
remove the engine for crankshaft repair.
Inspect the back of the inserts for fractures, scrap-
ings or irregular wear patterns.
Inspect the upper insert locking tabs for damage.
Replace all damaged or worn bearing inserts.
FITTING (CRANKSHAFT INSTALLED)
The main bearing caps, numbered (front to rear)
from 1 through 7 have an arrow to indicate the for-
Fig. 1 Removing Main Bearing Caps and Lower
Inserts
Fig. 2 Removing Upper Inserts
Fig. 3 Main Bearing Wear Patterns
J4.0L ENGINE 9 - 87

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.
Inspect all hose connections such as clamps, cou-
plings and fittings to make sure they are secure and
leaks are not present. The component should be re-
placed immediately if there is any evidence of degra-
dation that could result in failure.
Never attempt to repair a plastic fuel line/tube. Re-
place as necessary.
Avoid contact of any fuel tubes/hoses with other ve-
hicle components that could cause abrasions or scuff-
ing. Be sure that the plastic fuel lines/tubes are
properly routed to prevent pinching and to avoid heat
sources.
The lines/tubes/hoses used on fuel injected vehicles
are of a special construction. This is due to the
higher fuel pressures and the possibility of contami-
nated fuel in this system. If it is necessary to replace
these lines/tubes/hoses, only those marked EFM/EFI
may be used.
The hose clamps used to secure rubber hoses on
fuel injected vehicles are of a special rolled edge con-
struction. This construction is used to prevent the
edge of the clamp from cutting into the hose. Only
these rolled edge type clamps may be used in this
system. All other types of clamps may cut into the
hoses and cause high-pressure fuel leaks.
Use new original equipment type hose clamps.
Tighten hose clamps to 1 Nzm (15 in. lbs.) torque.
QUICK-CONNECT FITTINGS
Also refer to the previous Fuel Tubes/Lines/Hoses
and Clamps section.
Different types of quick-connect fittings are used to
attach various fuel system components. These are: a
single-tab type, a two-tab type or a plastic retainer
ring type.
SINGLE-TAB TYPE
This type of fitting is equipped with a single pull
tab (Fig. 15). The tab is removable. After the tab is
removed, the quick-connect fitting can be separated
from the fuel system component.
CAUTION: The interior components (O-rings, spac-
ers) of this type of quick-connect fitting are not ser-
viced separately, but new pull tabs 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) Disconnect negative battery cable from battery.
(2) Perform the fuel pressure release procedure.
Refer to the Fuel Pressure Release Procedure in this
section.
(3) Clean the fitting of any foreign material before
disassembly.
(4) Press the release tab on the side of fitting to re-
lease pull tab (Fig. 15).
CAUTION: If this release tab is not pressed prior to
releasing the pull tab, the pull tab will be damaged.
(5) While pressing the release tab on the side of
the fitting, use a screwdriver to pry up the pull tab
(Fig. 16).
(6) Raise the pull tab until it separates from the
quick-connect fitting (Fig. 17). Discard the old pull
tab.
(7) Disconnect the quick-connect fitting from the
fuel system component being serviced.
(8) Inspect the quick-connect fitting body and fuel
system component for damage. Replace as necessary.
(9) Prior to connecting the quick-connect fitting to
component being serviced, check condition of fitting
and component. Clean the parts with a lint-free
cloth. Lubricate them with clean engine oil.
(10) Insert the quick-connect fitting into the fuel
tube or fuel system component until the built-on stop
on the fuel tube or component rests against back of
fitting.
Fig. 15 Single-Tab Type Fitting
14 - 10 FUEL DELIVERY SYSTEMJ

(11) Obtain a new pull tab. Push the new tab down
until it locks into place in the quick-connect fitting.
(12) Verify a locked condition by firmly pulling on
fuel tube and fitting (15-30 lbs.).
(13) Connect negative cable to battery.
(14) Start engine and check for leaks.
TWO-TAB TYPE FITTING
This type of fitting is equipped with tabs located on
both sides of the fitting (Fig. 18). 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) Disconnect negative battery cable from the bat-
tery.
(2) Perform the fuel pressure release procedure.
Refer to the Fuel Pressure Release Procedure in this
section.
(3) Clean the fitting of any foreign material before
disassembly.
(4) To disconnect the quick-connect fitting, squeeze
the plastic retainer tabs against the sides of the
quick-connect fitting with your fingers. Tool use is
not required for removal and may damage plastic re-
tainer. Pull the fitting from the fuel system compo-
nent being serviced. The plastic retainer will remain
on the component being serviced after fitting is dis-
connected. The O-rings and spacer will remain in the
quick-connect fitting connector body.
(5) Inspect the quick-connect fitting body and com-
ponent 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.
(6) Prior to connecting the quick-connect fitting to
component being serviced, check condition of fitting
and component. Clean the parts with a lint-free
cloth. Lubricate them with clean engine oil.
Fig. 16 Disconnecting Single-Tab Type Fitting
Fig. 17 Removing Pull Tab
Fig. 18 Typical Two-Tab Type Quick-Connect Fitting
JFUEL DELIVERY SYSTEM 14 - 11

(7) Insert the quick-connect fitting to the compo-
nent being serviced and into the plastic retainer.
When a connection is made, a click will be heard.
(8) Verify a locked condition by firmly pulling on
fuel tube and fitting (15-30 lbs.).
(9) Connect negative cable to battery.
(10) Start engine and check for leaks.
PLASTIC RETAINER RING TYPE FITTING
This type of fitting can be identified by the use of a
full-round plastic retainer ring (Fig. 19) usually black
in color.
CAUTION: The interior components (O-rings, spac-
ers, retainers) of this type of quick-connect fitting
are not serviced separately. Do not attempt to repair
damaged fittings or fuel lines/tubes. If repair is nec-
essary, 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) Disconnect negative battery cable from the bat-
tery.
(2) Perform the fuel pressure release procedure.
Refer to the Fuel Pressure Release Procedure in this
section.
(3) Clean the fitting of any foreign material before
disassembly.
(4) To release the fuel system component from the
quick-connect fitting, firmly push the fitting towards
the component being serviced while firmly pushing
the plastic retainer ring into the fitting (Fig. 19).
With the plastic ring depressed, pull the fitting from
the component.The plastic retainer ring must be
pressed squarely into the fitting body. If this re-
tainer is cocked during removal, it may be dif-
ficult to disconnect fitting. Use an open-end
wrench on the shoulder of the plastic retainer
ring to aid in disconnection.
After disconnection, the plastic retainer ring will
remain with the quick-connect fitting connector body.
(5) Inspect fitting connector body, plastic retainer
ring and fuel system component for damage. Replace
as necessary.
(6) Prior to connecting the quick-connect fitting to
component being serviced, check condition of fitting
and component. Clean the parts with a lint-free
cloth. Lubricate them with clean engine oil.
(7) Insert the quick-connect fitting into the compo-
nent being serviced until a click is felt.
(8) Verify a locked condition by firmly pulling on
fuel tube and fitting (15-30 lbs.).
(9) Connect negative battery cable to battery.
(10) Start engine and check for leaks.
Fig. 19 Plastic Retainer Ring Type Fitting
14 - 12 FUEL DELIVERY SYSTEMJ

MULTI-PORT FUEL INJECTION (MFI)ÐCOMPONENT DESCRIPTION/SYSTEM
OPERATION
INDEX
page page
Air Cleaner.............................. 29
Air Conditioning (A/C) Clutch RelayÐPCM Output . 26
Air Conditioning (A/C) ControlsÐPCM Input...... 21
Auto Shutdown (ASD) RelayÐPCM Output...... 26
Automatic Shutdown (ASD) SenseÐPCM Input . . . 21
Battery VoltageÐPCM Input................. 21
Brake SwitchÐPCM Input................... 22
Camshaft Position SensorÐPCM Input......... 22
Crankshaft Position SensorÐPCM Input........ 22
Data Link ConnectorÐPCM Input............. 22
Data Link ConnectorÐPCM Output............ 27
EMR LampÐPCM Output................... 27
Engine Coolant Temperature SensorÐPCM Input . 23
Extended Idle SwitchÐPCM Input............. 23
Fuel InjectorsÐPCM Output................. 27
Fuel Pressure Regulator.................... 33
Fuel Pump RelayÐPCM Output.............. 27
Fuel Rail................................ 33
General Information....................... 19
Generator FieldÐPCM Output................ 27
Generator LampÐPCM Output............... 27
Idle Air Control (IAC) MotorÐPCM Output....... 27
Ignition Circuit SenseÐPCM Input............. 23
Ignition CoilÐPCM Output................... 28Intake Manifold Air Temperature SensorÐ
PCM Input............................. 22
Malfunction Indicator LampÐPCM Output....... 28
Manifold Absolute Pressure (MAP) SensorÐPCM
Input................................. 23
Open Loop/Closed Loop Modes of Operation..... 30
Oxygen (O2S) SensorÐPCM Input............ 24
Park/Neutral SwitchÐPCM Input.............. 24
Power Ground........................... 24
Power Steering Pressure SwitchÐPCM Input.... 24
Powertrain Control Module (PCM)............. 20
Radiator Fan RelayÐPCM Output............. 28
SCI ReceiveÐPCM Input................... 24
SCI TransmitÐPCM Output.................. 29
Sensor ReturnÐPCM Input.................. 25
Shift IndicatorÐPCM Output................. 29
Speed ControlÐPCM Input.................. 25
Speed ControlÐPCM Output................. 29
TachometerÐPCM Output................... 29
Throttle Body............................ 33
Throttle Position Sensor (TPS)ÐPCM Input...... 25
Torque Converter Clutch RelayÐPCM Output.... 29
Vehicle Speed SensorÐPCM Input............ 25
GENERAL INFORMATION
All 2.5L 4-cylinder and 4.0L 6-cylinder engines are
equipped with sequential Multi-Port Fuel Injection
(MFI). The MFI system provides precise air/fuel ra-
tios for all driving conditions.
The Powertrain Control Module (PCM) operates
the fuel system. The PCM was formerly referred to
as the SBEC or engine controller. The PCM is a pre-
programmed, dual microprocessor digital computer. It
regulates ignition timing, air-fuel ratio, emission con-
trol devices, charging system, speed control, air con-
ditioning compressor clutch engagement and idle
speed. The PCM can adapt its programming to meet
changing operating conditions.
Powertrain Control Module (PCM) Inputsrep-
resent the instantaneous engine operating conditions.
Air-fuel mixture and ignition timing calibrations for
various driving and atmospheric conditions are pre-
programmed into the PCM. The PCM monitors and
analyzes various inputs. It then computes engine fuel
and ignition timing requirements based on these in-
puts. Fuel delivery control and ignition timing will
then be adjusted accordingly.
Other inputs to the PCM are provided by the brake
light switch, air conditioning select switch and the
speed control switches. All inputs to the PCM are
converted into signals.
Electrically operated fuel injectors spray fuel inprecise metered amounts into the intake port directly
above the intake valve. The injectors are fired in a
specific sequence by the PCM. The PCM maintains
an air/fuel ratio of 14.7 to 1 by constantly adjusting
injector pulse width. Injector pulse width is the
length of time that the injector opens and sprays fuel
into the chamber. The PCM adjusts injector pulse
width by opening and closing the ground path to the
injector.
Manifold absolute pressure (air density) and engine
rpm (speed) are the primary inputs that determine
fuel injector pulse width. The PCM also monitors
other inputs when adjusting air-fuel ratio.
Inputs That Effect Fuel Injector Pulse Width:
²Exhaust gas oxygen content
²Engine coolant temperature
²Manifold absolute pressure (MAP)
²Engine speed
²Throttle position
²Battery voltage
²Air conditioning selection
²Transmission gear selection (automatic transmis-
sions only)
²Speed control
The powertrain control module (PCM) adjusts igni-
tion timing by controlling ignition coil operation. The
ignition coil receives battery voltage when the igni-
tion key is in the run or starter position. The PCM
JFUEL SYSTEM COMPONENT DESCRIPTION/SYSTEM OPERATION 14 - 19

provides a ground for the ignition coil. The coil dis-
charges when the PCM supplies a ground. By switch-
ing the ground path on and off, the PCM regulates
ignition timing.
The sensors and switches that provide inputs to
the powertrain control module (PCM) comprise the
Engine Control System. It is also comprised of the
PCM Outputs (engine control devices that the are op-
erated by the PCM).
SYSTEM DIAGNOSIS
The powertrain control module (PCM) tests many
of its own input and output circuits. If a Diagnostic
Trouble Code (DTC) is found in a major system, this
information is stored in the PCM memory. Refer to
On-Board Diagnostics in the MFI SystemÐGeneral
Diagnosis section of this group for DTC information.
POWERTRAIN CONTROL MODULE (PCM)
The PCM operates the fuel system. The PCM was
formerly referred to as the SBEC or engine control-
ler. The PCM is a pre-programmed, dual microproces-
sor digital computer. It regulates ignition timing, air-
fuel ratio, emission control devices, charging system,
speed control, air conditioning compressor clutch en-
gagement and idle speed. The PCM can adapt its
programming to meet changing operating conditions.
On XJ models, the PCM is located in the engine
compartment next to the air cleaner (Fig. 1). On YJ
models, the PCM is located in the engine compart-
ment behind the windshield washer fluid reservoir
(Fig. 2).
The PCM receives input signals from various
switches and sensors. Based on these inputs, the
PCM regulates various engine and vehicle operations
through different system components. These compo-
nents are referred to as PCM Outputs. The sensors
and switches that provide inputs to the PCM are con-
sidered PCM Inputs.The PCM adjusts ignition timing based upon in-
puts it receives from sensors that react to: engine
rpm, manifold absolute pressure, coolant tempera-
ture, throttle position, transmission gear selection
(automatic transmission), vehicle speed and the
brake switch.
The PCM adjusts idle speed based on inputs it re-
ceives from sensors that react to: throttle position,
vehicle speed, transmission gear selection, coolant
temperature and from inputs it receives from the air
conditioning clutch switch and brake switch.
Based on inputs that it receives, the PCM adjusts
ignition coil dwell. The PCM also adjusts the gener-
ator charge rate through control of the generator
field and provides speed control operation.
Powertrain Control Module (PCM) Inputs:
²Generator output
²A/C request (if equipped with factory A/C)
²A/C select (if equipped with factory A/C)
²Auto shutdown (ASD) sense
²Intake manifold air temperature sensor
²Battery voltage
²Brake switch
²Engine coolant temperature sensor
²Crankshaft position sensor
²Ignition circuit sense (ignition switch in run posi-
tion)
²Manifold absolute pressure sensor
²Overdrive/override switch
²Oxygen sensor
²Park/neutral switch (auto. trans. only)
²SCI receive (DRB scan tool connection)
²Speed control resume switch
²Speed control set switch
²Speed control on/off switch
²Camshaft position sensor signal
²Throttle position sensor
²Vehicle speed sensor
²Sensor return
²Power ground
Fig. 1 PCM LocationÐXJ Models
Fig. 2 PCM LocationÐYJ Models
14 - 20 FUEL SYSTEM COMPONENT DESCRIPTION/SYSTEM OPERATIONJ

²Signal ground
Powertrain Control Module (PCM) Outputs:
²A/C clutch relay
²Idle air control (IAC) motor
²Auto shutdown (ASD) relay
²Generator field
²Malfunction indicator lamp (Check Engine Lamp)
²Fuel injectors
²Fuel pump relay
²Ignition coil
²SCI transmit (DRB scan tool connection)
²Shift indicator lamp (manual transmission only)
²Speed control vacuum solenoid
²Speed control vent solenoid
²Tachometer (on instrument panel, if equipped)
²Torque converter clutch relay (3-speed auto. trans.
only)
The PCM contains a voltage convertor. This con-
verts battery voltage to a regulated 8.0 volts. It is
used to power the crankshaft position sensor, cam-
shaft position sensor and vehicle speed sensor. The
PCM also provides a five (5) volt supply for the Man-
ifold Absolute Pressure (MAP) sensor and Throttle
Position Sensor (TPS).
AIR CONDITIONING (A/C) CONTROLSÐPCM INPUT
The A/C control system information applies to fac-
tory installed air conditioning units only.
A/C SELECT SIGNAL:When the A/C switch is in
the ON position and the A/C low-pressure switch is
closed, an input signal is sent to the powertrain con-
trol module (PCM). The signal informs the PCM that
the A/C has been selected. The PCM adjusts idle
speed to a pre-programmed rpm through the idle air
control (IAC) motor to compensate for increased en-
gine load.
A/C REQUEST SIGNAL:Once A/C has been se-
lected, the PCM receives the A/C request signal from
the evaporator switch. The input indicates that the
evaporator temperature is in the proper range for
A/C application. The PCM uses this input to cycle the
A/C compressor clutch (through the A/C relay). It will
also determine the correct engine idle speed through
the IAC motor position.
If the A/C low-pressure switch opens (indicating a
low refrigerant level), the PCM will not receive an
A/C select signal. The PCM will then remove the
ground from the A/C relay. This will deactivate the
A/C compressor clutch.
If the evaporator switch opens, (indicating that
evaporator is not in proper temperature range), the
PCM will not receive the A/C request signal. The
PCM will then remove the ground from the A/C relay,
deactivating the A/C compressor clutch.
AUTOMATIC SHUTDOWN (ASD) SENSEÐPCM
INPUT
A 12 volt signal at this input indicates to the PCM
that the ASD has been activated. The ASD relay is
located in the power distribution center (PDC) in the
engine compartment (Figs. 3 or 4). It is used to con-
nect the ignition coil, generator field winding and
fuel injectors to 12 volt + power supply. Also refer to
Automatic Shutdown RelayÐPCM Output.
This input is used only to sense that the ASD relay
is energized. If the PCM does not see 12 volts at this
input when the ASD should be activated, it will set a
Diagnostic Trouble Code (DTC).
BATTERY VOLTAGEÐPCM INPUT
The battery voltage input provides power to the
powertrain control module (PCM). It also informs the
PCM what voltage level is supplied to the ignition
coil and fuel injectors.
If battery voltage is low, the PCM will increase in-
jector pulse width (period of time that the injector is
Fig. 3 Power Distribution CenterÐYJ Models
Fig. 4 Power Distribution CenterÐXJ Models
JFUEL SYSTEM COMPONENT DESCRIPTION/SYSTEM OPERATION 14 - 21