
The pressure regulator is a mechanical device that
is NOT controlled by the PCM or engine vacuum.
REMOVAL
The fuel pressure regulator is part of the fuel
pump module (Fig. 9). Remove the fuel pump module
from the fuel tank to access the fuel pressure regula-
tor. Refer to the Fuel Pump Module removal in this
section.
(1) Spread tangs on pressure regulator retainer.
(2) Pry fuel pressure regulator out of housing.
(3) Ensure both upper and lower O-rings were
removed with regulator.
INSTALLATION
The fuel pressure regulator is part of the fuel
pump module. Remove the fuel pump module from
the fuel tank to access the fuel pressure regulator.
Refer to the Fuel Pump Module removal in this sec-
tion.
(1)
Lightly lubricate the O-rings with clean engine oil
and place them into opening in pump module (Fig. 9).
(2) Push regulator into opening in pump module.
(3) Fold tangs on regulator retainer over tabs on
housing.
FUEL PUMP
DESCRIPTION
The electric fuel pump is located in and is part of
the fuel pump module. It is a positive displacement,
gerotor type, immersible pump with a permanent
magnet electric motor. The fuel pump module is sus-
pended in fuel in the fuel tank.
OPERATION
The pump draws fuel through a strainer and
pushes it through the motor to the outlet. The pump
contains a check valve. The valve, in the pump out-
let, maintains pump pressure during engine off con-
ditions. The fuel pump relay provides voltage to the
fuel pump. The fuel pump has a maximum dead-
headed pressure output of approximately 880 kPa
(130 psi). The regulator adjusts fuel system pressure
to approximately 400 kpa634 kpa (58 psi65 psi).
FUEL PUMP MODULE
DESCRIPTION
The fuel pump module is installed in the top of the
fuel tank (Fig. 10).
The fuel pump module contains the following:
²Electric fuel pump
²Fuel pump reservoir
²Inlet strainer
²Fuel pressure regulator
²Fuel gauge sending unit
²Fuel supply line connection
The inlet strainer, fuel pressure regulator
and fuel level sensor are the only serviceable
items. If the fuel pump or electrical wiring har-
ness requires service, replace the fuel pump
module.
The electric fuel pump is located in and is part of
the fuel pump module. It is a positive displacement,
gerotor type, immersible pump with a permanent
magnet electric motor.
OPERATION
The pump draws fuel through a strainer and
pushes it through the motor to the outlet. The pump
contains one check valve. The check valve, in the
Fig. 9 Fuel Pressure Regulator O-rings
1 - UPPER O-RING
2 - LOWER 0-RING
Fig. 10 Fuel Pump Module
1 - INLET STRAINER
2 - FUEL RESERVOIR
3 - FUEL PRESSURE REGULATOR
4 - FUEL LEVEL SENSOR
RSFUEL DELIVERY14-7
FUEL PRESSURE REGULATOR (Continued)

(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.
(6) Prior to connecting quick-connect fitting to
component being serviced, check condition of fitting
and component. Clean parts with a lint-free cloth.
Lubricate with clean engine oil.
(7) Insert quick-connect fitting to component being
serviced and into 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 or auxiliary
jumper terminal.
(10) Use the DRB IIItscan tool ASD Fuel System
Test to pressurize the fuel system. Check for leaks.
Fig. 24 Typical Two-Tab Type Quick-Connect Fitting
1 - TAB(S)
2 - QUICK-CONNECT FITTING
14 - 14 FUEL DELIVERYRS
QUICK CONNECT FITTING (Continued)

PLASTIC RETAINER RING TYPE FITTING
This type of fitting can be identified by the use of a
full-round plastic retainer ring (Fig. 25) 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
SYSTEM PRESSURE RELEASE PROCEDURE IN
THIS GROUP.DISCONNECTION/CONNECTION
(1) Perform fuel pressure release procedure. Refer
to Fuel Pressure Release Procedure in this section.
(2) Disconnect negative battery cable from battery
or auxiliary jumper terminal.
(3) Clean fitting of any foreign material before dis-
assembly.
(4) To release fuel system component from quick-
connect fitting, firmly push fitting towards compo-
nent being serviced while firmly pushing plastic
retainer ring into fitting (Fig. 25). With plastic ring
depressed, pull fitting from component.The plastic
retainer ring must be pressed squarely into fit-
ting body. If this retainer is cocked during
removal, it may be difficult to disconnect fit-
ting. Use an open-end wrench on shoulder of
plastic retainer ring to aid in disconnection.
(5) After disconnection, plastic retainer ring will
remain with quick-connect fitting connector body.
(6) Inspect fitting connector body, plastic retainer
ring and fuel system component for damage. Replace
as necessary.
(7) Prior to connecting quick-connect fitting to
component being serviced, check condition of fitting
and component. Clean parts with a lint-free cloth.
Lubricate with clean engine oil.
(8) Insert quick-connect fitting into component
being serviced until a click is felt.
(9) Verify a locked condition by firmly pulling on
fuel tube and fitting (15-30 lbs.).
(10) Connect negative battery cable to battery or
auxiliary jumper terminal.
(11) Use the DRB IIItscan tool ASD Fuel System
Test to pressurize the fuel system. Check for leaks.
ROLLOVER VALVE
DESCRIPTION
All vehicles have rollover valve(s) on top of the fuel
tank.
OPERATION
The valves prevent fuel flow through the fuel tank
vent valve hoses should the vehicle rollover.
The rollover valves on the fuel tank are not ser-
viceable.
Fig. 25 Plastic Retainer Ring Type Fitting
1 - FUEL TUBE
2 - QUICK CONNECT FITTING
3 - PUSH
4 - PLASTIC RETAINER
5 - PUSH
6 - PUSH
7 - PUSH
8 - PUSH
RSFUEL DELIVERY14-15
QUICK CONNECT FITTING (Continued)

FUEL TRANSFER PUMP
DESCRIPTION
The fuel transfer pump (fuel lift pump) is located
under the vehicle in front of the rear axle assembly
(Fig. 5). The 12±volt electric vane-type pump is oper-
ated and controlled by the Engine Control Module
(ECM) .
OPERATION
The purpose of the fuel transfer pump is to supply
(transfer) a low-pressure fuel source:fromthe fuel
tank,throughthe fuel filter/water separator andto
the fuel injection pump. Here, the low-pressure is
raised to a high-pressure by the fuel injection pump
for operation of the high-pressure fuel injectors.The fuel transfer pump is controlled by the Engine
Control Module(ECM). The ECM turns the fuel
transfer pump on for 30 seconds when the ignition
ket is turned ªONº.
With the ignition ªONº and fuel tranfer pump run-
ning, the low-pressure fuel pressure should be 13-17 psi.
FUEL INJECTION PUMP
DESCRIPTION
A radial-piston pump is used as the high pressure
pump for fuel pressure generation (Fig. 6).
REMOVAL
(1) Disconnect negative battery cable.
(2) Remove engine cover (Refer to 9 - ENGINE -
REMOVAL)
(3) Remove air cleaner housing assembly.
(4) Remove power steering belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(5) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(6) Support engine and remove right engine mount
assembly.
(7) Remove outer timing belt cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL).
(8) Using special tool VM.1055, remove injection
pump sprocket retaining nut (Fig. 7).
Fig. 5 FUEL TRANSFER(LIFT) PUMP LOCATION
1 - LIFT PUMP RETAINING BOLTS
2 - LIFT PUMP
3 - FUEL FILTER/WATER SEPARATOR HOUSING
4 - FUEL HEATER
5 - CHECK BALL
6 - O-RING
7 - FLOW DIVERTER
8 - FUEL FILTER
9 - O-RING
10 - FUEL FILTER BOWL ASSEMBLY
Fig. 6 FUEL INJECTION PUMP
1 - FUEL INJECTION PUMP
2 - INJECTION PUMP PRESSURE SOLENOID
14a - 6 FUEL DELIVERYRG

(3) Disconnect intake air temperature electrical
connector.
(4) Remove intake air temperature sensor retain-
ing screws and sensor (Fig. 6).
INSTALLATION
(1) Install intake air temperature sensor and
retaining bolts (Fig. 6). Torque to 5.4 N´m.
(2) Connect intake air temperature sensor.
(3) Install engine cover and retaining bolts (Refer
to 9 - ENGINE COVER - INSTALLATION).
CRANKSHAFT POSITION
SENSOR
DESCRIPTION
The crankshaft position sensor is mounted in the
right rear of the engine block below the turbocharger
(Fig. 7). This sensor is used to detect engine speed.
OPERATION
The crankshaft position sensor is a magnetic
pickup type sensor that generates an ac signal. The
sensor contains a permanent magent and a coil of
wire. The sensor generates an ac signal each time a
notch in the reluctor wheel on the crankshaft passesacross the permanent magnet. The ECM calculates
engine speed based on the frequency of the ac signal.
The ECM supplies the sensor ground.
MASS AIR FLOW (MAF)
SENSOR
DESCRIPTION
The Mass Air Flow (MAF) Sensor is mounted
inline in the air intake between the air filter and the
turbocharger (Fig. 8).
Fig. 6 BOOST PRESSURE SENSOR/INTAKE AIR
TEMPERATURE SENSOR LOCATION
1 - FUEL RAIL
2 - FUEL PRESSURE SENSOR
3 - INTAKE AIR TEMPERATURE/BOOST PRESSURE SENSOR
4 - CYLINDER HEAD COVER/INTAKE MANIFOLD
Fig. 7 CRANKSHAFT POSITION SENSOR
1 - CRANKSHAFT POSITION SENSOR
2 - CRANKSHAFT POSITION SENSOR ELECTRICAL
CONNECTOR
Fig. 8 MASS AIR FLOW (MAF) SENSOR
14a - 14 FUEL INJECTIONRG
INTAKE AIR TEMPERATURE SENSOR (Continued)

Euro Stage III OBD MONITOR INFORMATION
Comprehensive Major Monitors Major Monitors
Components Non Fuel Control Fuel Control
Monitor & Non Misfire & Misfire
Run constantly Run Once Per Trip Run Constantly
Includes All Engine Hardware Monitors Entire Emission Monitors Entire System
- Sensors, Switches, System
Solenoids, etc.
One Trip Faults - Turns On Two Trip Faults - Turns On Two Trip Faults - Turns On
The MIL and Sets DTC After The MIL and Sets DTC After The MIL and Sets DTC After
One Failure Two Consecutive Failures Two Consecutive Failures
Priority 3 Priority 1 or 3 Priority 2 or 4
All Checked For Continuity Done Stop Testing = Yes
Fuel Control Monitor
Open Monitors Fuel Control
Short To Ground Oxygen Sensor Heater System For:
Short To Voltage Oxygen Sensor Response
Fuel System Lean
Fuel System Rich
Inputs Checked For
Requires 3 Consecutive Rationality
Catalytic Converter
Fuel System Good TripsTo Efficiency Except EWMA
Extinguish The MIL Outputs Checked For - up to 6 tests per trip
Functionality and a one trip fault
EGR System
Misfire Monitor
Evaporative Emission Monitors For Engine Misfire
System at:
(Purge and Leak) 1000 RPM Counter
Non-LDP (Type B)
or **200 RPM Counter
LDP (Type A)
Requires 3 Consecutive Requires 3 Consecutive Requires 3 Consecutive
Global/Alternate Good Trips Global Good Trips Misfire Good Trips
to Extinguish the MIL* to Extinguish the MIL* To Extinguish the MIL
*40 Warm Up Cyclesare required to erase **Type A misfire is a two
DTC's
afterthe MIL has been extinguished. trip failure. The MIL will
illuminate and blink at
the first failure.
3
GENERAL INFORMATION

3.2.3 OTHER CONTROLS
CHARGING SYSTEM
The charging system is turned on when the
engine is started and ASD relay energized. When
the ASD relay is on, ASD output voltage is supplied
to the ASD sense circuit at the PCM. This voltage is
connected in some cases, through the PCM and
supplied to one of the generator field terminals
(Gen Source +). All others, the Gen field is con-
nected directly to the ASD output voltage. The
amount of current produced by the generator is
controlled by the Electronic Voltage Regulator
(EVR) circuitry, in the PCM. Battery temperature is
determined from IAT. This temperature along with
sensed line voltage, is used by the PCM to vary the
battery charging rate. This is done by cycling the
ground path to the other generator field terminal
(Gen field driver).
SPEED CONTROL SYSTEM
The PCM controls vehicle speed by operation of
the speed control servo vacuum and vent solenoids.
Energizing the vacuum solenoid applies vacuum to
the servo to increase throttle position. Operation of
the vent solenoid slowly releases the vacuum allow-
ing throttle position to decrease. A special dump
solenoid allows immediate release of throttle posi-
tion caused by braking, cruise control switch turned
off, shifting into neutral, excessive RPM (tires spin-
ning) or ignition off.
LEAK DETECTION PUMP SYSTEM (IF EQUIPPED)
The leak detection pump is a device that pressur-
izes the evaporative system to determine if there
are any leaks. When certain conditions are met, the
PCM will activate the pump and start counting
pump strokes. If the pump stops within a calibrated
number of strokes, the system is determined to be
normal. If the pump does not stop or stops too soon,
a DTC will be set.
3.2.4 PCM OPERATING MODES
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. There are several different
modes of operation that determine how the PCM
responds to the various input signals.
There are two types of engine control operation:
open loopandclosed loop.
Inopen loopoperation, the PCM receives input
signals and responds according to preset program-
ming. Inputs from the heated oxygen sensors are
not monitored.Inclosed loopoperation, the PCM monitors the
inputs from the heated oxygen sensors. This input
indicates to the PCM whether or not the calculated
injector pulse width results in the ideal air-fuel
ratio of 14.7 parts air to 1 part fuel. By monitoring
the exhaust oxygen content through the oxygen
sensor, the PCM can fine tune injector pulse width.
Fine tuning injector pulse width allows the PCM to
achieve the lowest emission levels while maintain-
ing optimum fuel economy.
The engine start-up (crank), engine warm-up,
and wide open throttle modes are open loop modes.
Under most operating conditions, closed loop modes
occur with the engine at operating temperature.
IGNITION SWITCH ON (ENGINE OFF) MODE
When the ignition switch activates the fuel injec-
tion system, the following actions occur:
1. The PCM determines atmospheric air pressure
from the MAP sensor input to determine basic
fuel strategy.
2. The PCM monitors the engine coolant tempera-
ture sensor and throttle position sensor input.
The PCM modifies fuel strategy based on this
input.
When the key is in the on position and the engine
is not running (zero rpm), the auto shutdown relay
and fuel pump relay are not energized. Therefore,
voltage is not supplied to the fuel pump, ignition
coil, and fuel injectors.
Engine Start-up ModeÐ This is an open loop
mode. The following actions occur when the starter
motor is engaged:
1. The auto shutdown and fuel pump relays are
energized. If the PCM does not receive the cam-
shaft and crankshaft signal within approxi-
mately one second, these relays are de-
energized.
2. The PCM energizes all fuel injectors until it
determines crankshaft position from the cam-
shaft and crankshaft signals. The PCM deter-
mines crankshaft position within one engine
revolution. After the camshaft position has been
determined, the PCM energizes the fuel injectors
in sequence. The PCM adjusts the injector pulse
width and synchronizes the fuel injectors by
controlling the fuel injectors' ground paths.
3. Once the engine idles within 64 rpm of its target
engine speed, the PCM compares the current
MAP sensor value with the value received dur-
ing the ignition switch on (zero rpm) mode. A
diagnostic trouble code is written to PCM mem-
ory if a minimum difference between the two
values is not found.
4
GENERAL INFORMATION