(9) Remove 3 screws holding PCM to fender (Fig.
121).
(10) Remove PCM from vehicle.
INSTALLATION
(1) Connect 2 40-Way electrical connectors to PCM
(Fig. 120).
(2) Install PCM. Tighten mounting screws.
(3) Install PDC bracket.
(4) Install battery.
CRANKSHAFT POSITION SENSOR
For removal/installation procedures refer to group
8D - Ignition System, Service Procedures.
CAMSHAFT POSITION SENSOR
For removal/installation procedures refer to group
8D - Ignition System, Service Procedures.
UPSTREAM OXYGEN SENSOR
The oxygen sensor is installed in the exhaust man-
ifold (Fig. 122) or (Fig. 123) or (Fig. 124).
CAUTION: Do not pull on the oxygen sensor wire
when unplugging the electrical connector.
WARNING: THE EXHAUST MANIFOLD AND CATA-
LYTIC CONVERTER MAY BE EXTREMELY HOT. USE
CARE WHEN SERVICING THE OXYGEN SENSOR.
REMOVAL
(1) Raise and support vehicle.
(2) Unplug oxygen sensor electrical connector.
(3) Use a socket such as Snap-On YA8875 or
equivalent to remove sensor.
Fig. 119 PDC Rear Bracket
Fig. 120 PCM 40-Way Connectors
Fig. 121 PCM Removal/Installation
Fig. 122 Upstream Heated Oxygen SensorÐ2.4L
14 - 68 FUEL SYSTEMNS
REMOVAL AND INSTALLATION (Continued)
(4) When the sensor is removed, the exhaust man-
ifold threads must be cleaned with an 18 mm X 1.5 +
6E tap. If using original sensor, coat the threads with
Loctite 771-64 anti-seize compound or equivalent.
INSTALLATION
(1) Reverse removal procedure to install a new
sensor.
New sensors are packaged with compound on the
threads and no additional compound is required. The
sensor must be tightened to 27 N´m (20 ft. lbs.)
torque.
DOWNSTREAM OXYGEN SENSOR
REMOVAL
(1) Raise and support vehicle.
WARNING: THE EXHAUST MANIFOLD MAY BE
EXTREMELY HOT. USE CARE WHEN SERVICING
THE OXYGEN SENSOR.(2) Remove grommet cover to expose connector
(Fig. 125).
(3) Push locking tab back and unplug oxygen sen-
sor electrical connector (Fig. 126).
(4) Use a socket such as Snap-On YA8875 or
equivalent to remove sensor (Fig. 127).
Fig. 123 Upstream Heated Oxygen SensorÐ3.0L
Fig. 124 Upstream Heated Oxygen SensorÐ3.3/3.8L
Fig. 125 Oxygen Sensor Grommet Cover
Fig. 126 Oxygen Sensor Connector Locking Tab
Fig. 127 Oxygen Sensor Removal/Installation
NSFUEL SYSTEM 14 - 69
REMOVAL AND INSTALLATION (Continued)
(5) When the sensor is removed, the exhaust man-
ifold threads must be cleaned with an 18 mm X 1.5 +
6E tap. If using original sensor, coat the threads with
Loctite 771-64 anti-seize compound or equivalent.
INSTALLATION
(1) Reverse removal procedure to install a new
sensor.
New sensors are packaged with compound on the
threads and no additional compound is required. The
sensor must be tightened to 27 N´m (20 ft. lbs.)
torque.
KNOCK SENSOR
For removal/installation procedures refer to Group
8D- Ignition System, Service Procedures.
AIR CLEANER ELEMENT
REMOVAL
(1) Remove 2 screws and air inlet resonator (Fig.
128).
(2) Loosen 3 clamps holding air cleaner housing
halves together.
(3) Remove left side of air cleaner housing (Fig.
129).
(4) Remove element from air cleaner housing (Fig.
130).
INSTALLATION
(1) Install a new element in housing.
(2) Position left side of housing.
(3) Snap clamps into place.(4) Install hoses and air inlet resonator.
ENGINE COOLANT TEMPERATURE SENSORÐ2.4L
The coolant sensor threads into the top of the ther-
mostat housing (Fig. 131). New sensors have sealant
applied to the threads.
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
REFER TO GROUP 7- COOLING.Fig. 128 Air Inlet Resonator
Fig. 129 Air Cleaner Housing (Left Side)
Fig. 130 Air Cleaner Element
14 - 70 FUEL SYSTEMNS
REMOVAL AND INSTALLATION (Continued)
REMOVAL
(1) With the engine cold, drain coolant until level
drops below cylinder head. Refer to Group 7, Cooling
System.
(2) Disconnect coolant sensor electrical connector.
(3) Remove coolant sensor.
INSTALLATION
(1) Install coolant sensor. Tighten sensor to 7 N´m
(60 in. lbs.) torque.
(2) Attach electrical connector to sensor.
(3) Fill cooling system. Refer to Group 7, Cooling
System.
ENGINE COOLANT TEMPERATURE SENSORÐ3.0L
The sensor is installed next to the thermostat
housing (Fig. 114).
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
REFER TO GROUP 7- COOLING.
REMOVAL
(1) With the engine cold, drain coolant until level
drops below cylinder head. Refer to Group 7, Cooling
System.
(2) Disconnect coolant sensor electrical connector.
(3) Remove coolant sensor.
INSTALLATION
(1) Install coolant sensor. Tighten sensor to 7 N´m
(60 in. lbs.) torque.
(2) Attach electrical connector to sensor.
(3) Fill cooling system. Refer to Group 7, Cooling
System.
ENGINE COOLANT TEMPERATURE SENSORÐ3.3/
3.8L
The sensor is installed next to the thermostat
housing (Fig. 132).
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
REFER TO GROUP 7- COOLING.
REMOVAL
(1) With the engine cold, drain coolant until level
drops below cylinder head. Refer to Group 7, Cooling
System.
(2) Disconnect coolant sensor electrical connector.
(3) Remove coolant sensor.
INSTALLATION
(1) Install coolant sensor. Tighten sensor to 7 N´m
(60 in. lbs.) torque.
(2) Attach electrical connector to sensor.
(3) Fill cooling system. Refer to Group 7, Cooling
System.
Fig. 131 Engine Coolant Temperature SensorÐ2.4L
Fig. 132 Engine Coolant Temperature Sensor
NSFUEL SYSTEM 14 - 71
REMOVAL AND INSTALLATION (Continued)
INTAKE AIR TEMPERATURE SENSORÐ2.4L
The intake air temperature sensor threads into the
intake manifold plenum (Fig. 133).
REMOVAL
(1) Remove electrical connector from sensor.
(2) Remove sensor.
INSTALLATION
(1) Install sensor. Tighten sensor to 28 N´m (20 ft.
lbs.) torque.
(2) Attach electrical connector to sensor.
SPECIFICATIONS
TORQUE
DESCRIPTION TORQUE
Generator Brkt. to Intake Manifold BoltsÐ3.3/3.8L.54
N´m (40 ft. lbs.)
Coolant SensorÐ2.4L..........7N´m(62in.lbs.)
Coolant SensorÐ3.0L..........7N´m(62in.lbs.)
Coolant SensorÐ3.3/3.8L........7N´m(62in.lbs.)
Cly. Head to Intake Manifold
Strut BoltsÐ3.3/3.8L........54N´m(40ft.lbs.)
EGR Tube to Intake Manifold
Screws..................22N´m(200 in. lbs.)
Idle Air Control Motor..........2N´m(18in.lbs.)
Ignition Coil Fasteners.......12N´m(105 in. lbs.)
Intake Air Temperature Sensor . .28 N´m (20 ft. lbs.)
MAP SensorÐ2.4L............4N´m(35in.lbs.)
MAP SensorÐ3.0L............4N´m(35in.lbs.)
MAP SensorÐ3.3/3.8L..........4N´m(35in.lbs.)
Upstream O2S...............27N´m(20ft.lbs.)
Downstream O2S.............27N´m(20ft.lbs.)
Throttle Body Bolts..........26N´m(225 in. lbs.)
SPECIAL TOOLS
FUEL
Fig. 133 Intake Air Temperature Sensor
Extractor C±4334
Pressure Gauge Assembly C±4799±B
Fuel Pressure Test Adapter 6539
Spanner Wrench 6856
14 - 72 FUEL SYSTEMNS
REMOVAL AND INSTALLATION (Continued)
Metering Orifice
Fuel Line Tool
Fuel Line Adapter
Fuel Line Adapter 1/4
O2S (Oxygen Sensor) Remover/InstallerÐC-4907
NSFUEL SYSTEM 14 - 73
SPECIAL TOOLS (Continued)
FUEL DELIVERY SYSTEMÐ2.5L DIESEL ENGINE
INDEX
page page
DESCRIPTION AND OPERATION
FUEL DRAIN TUBES..................... 7
FUEL FILTER/WATER SEPARATOR.......... 4
FUEL GAUGE SENDING UNIT.............. 4
FUEL HEATER RELAY.................... 8
FUEL HEATER.......................... 8
FUEL INJECTION PUMP.................. 5
FUEL INJECTORS....................... 6
FUEL SHUTDOWN SOLENOID............. 5
FUEL SYSTEM PRESSURE WARNING....... 3
FUEL TANK MODULE.................... 4
FUEL TANK............................ 3
FUEL TUBES/LINES/HOSES AND CLAMPSÐ
LOW-PRESSURE TYPE................. 6
HIGH-PRESSURE FUEL LINES............. 7
INTRODUCTION........................ 3
QUICK-CONNECT FITTINGSÐLOW PRESSURE
TYPE............................... 7
WASTEGATE (TURBOCHARGER)........... 8
DIAGNOSIS AND TESTING
AIR IN FUEL SYSTEM................... 11
FUEL HEATER RELAY TEST.............. 12
FUEL INJECTION PUMP TEST............. 12
FUEL INJECTOR SENSOR TEST........... 12
FUEL INJECTOR TEST.................. 12
FUEL SHUTDOWN SOLENOID TEST........ 13
FUEL SUPPLY RESTRICTIONS............ 13GENERAL INFORMATION................. 9
HIGH-PRESSURE FUEL LINE LEAK TEST.... 14
VISUAL INSPECTION..................... 9
WASTEGATE (TURBOCHARGER).......... 14
SERVICE PROCEDURES
AIR BLEED PROCEDURES............... 14
FUEL INJECTION PUMP TIMING........... 15
REMOVAL AND INSTALLATION
ACCELERATOR PEDAL.................. 16
AIR CLEANER ELEMENT................. 16
FUEL DRAIN TUBES.................... 16
FUEL FILTER/WATER SEPARATOR......... 16
FUEL HEATER RELAY................... 17
FUEL HEATER......................... 17
FUEL INJECTION PUMP................. 19
FUEL INJECTORS...................... 22
FUEL LEVEL SENSOR................... 18
FUEL RESERVOIR MODULE.............. 25
FUEL SHUTDOWN SOLENOID............ 23
FUEL TANK........................... 23
HIGH-PRESSURE LINES................. 26
SPECIFICATIONS
FUEL INJECTOR FIRING SEQUENCE....... 27
FUEL SYSTEM PRESSURE............... 27
FUEL TANK CAPACITY.................. 27
IDLE SPEED.......................... 27
DESCRIPTION AND OPERATION
INTRODUCTION
This Fuel Delivery section will cover components
not controlled by the PCM. For components con-
trolled by the PCM, refer to the Fuel Injection Sys-
temÐ2.5L Diesel Engine section of this group.
The fuel heater relay, fuel heater and fuel gauge
are not operated by the PCM. These components are
controlled by the ignition (key) switch. All other fuel
system electrical components necessary to operate
the engine are controlled or regulated by the PCM.
FUEL SYSTEM PRESSURE WARNING
WARNING: HIGH±PRESSURE FUEL LINES DELIVER
DIESEL FUEL UNDER EXTREME PRESSURE FROM
THE INJECTION PUMP TO THE FUEL INJECTORS.
THIS MAY BE AS HIGH AS 45,000 KPA (6526 PSI).
USE EXTREME CAUTION WHEN INSPECTING FORHIGH±PRESSURE FUEL LEAKS. INSPECT FOR
HIGH±PRESSURE FUEL LEAKS WITH A SHEET OF
CARDBOARD (Fig. 1). HIGH FUEL INJECTION
PRESSURE CAN CAUSE PERSONAL INJURY IF
CONTACT IS MADE WITH THE SKIN.
FUEL TANK
The fuel tank and tank mounting used with the
diesel powered engine is the same as used with gas-
oline powered models, although the fuel tank module
is different.
The fuel tank contains the fuel tank module and
two rollover valves. Two fuel lines are routed to the
fuel tank module. One line is used for fuel supply to
the fuel filter/water separator. The other is used to
return excess fuel back to the fuel tank.
The fuel tank module contains the fuel gauge elec-
trical sending unit.An electrical fuel pump is not
used with the diesel engine.
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 3
For periodic draining of water from the bowl, refer
to Fuel Filter/Water Separator Removal/Installation
in this group.
FUEL SHUTDOWN SOLENOID
The fuel shutdown solenoid is controlled and
operated by the PCM.
The fuel shutdown (shut-off) solenoid is used to
electrically shut off the diesel fuel supply to the high-
pressure fuel injection pump. The solenoid is
mounted to the rear of the injection pump (Fig. 4).
The solenoid controls starting and stopping of the
engine regardless of the position of the accelerator
pedal. When the ignition (key) switch is OFF, the
solenoid is shut off and fuel flow is not allowed to the
fuel injection pump. When the key is placed in the
ON or START positions, fuel supply is allowed at the
injection pump.
FUEL INJECTION PUMP
The fuel injection pump is a mechanical distribu-
tor±type, Bosch VP36 series (Fig. 5). A gear on the
end of the injection pump shaft meshes with the
drive gear at the front of engine. The pump is
mechanically timed, relative to the position of the
cam and crankshaft. The PCM can make adjust-
ments to the timing of the injection pump.
The injection pump contains the fuel shutdown
solenoid, fuel temperature sensor, control sleeve sen-
sor, fuel quantity actuator and the fuel timing sole-
noid (Fig. 5).In the electronically controlled injection pump, the
pump plunger works the same as the pump plunger
in a mechanically controlled injection pump, but the
amount of fuel and the time the fuel is injected is
controlled by the vehicle's PCM, instead of by a
mechanical governor assembly. A solenoid controlled
by the PCM is used in place of the mechanical gov-
ernor assembly, and it moves a control sleeve inside
the pump that regulates the amount of fuel being
injected. There is no mechanical connection between
the accelerator pedal and the electronically controlled
injection pump. Instead, a sensor connected to the
accelerator pedal sends a signal to the PCM that rep-
resents the actual position of the accelerator pedal.
The PCM uses this input, along with input from
other sensors to move the control sleeve to deliver
the appropriate amount of fuel. This system is known
as ªDrive-By-Wireº
The actual time that the fuel is delivered is very
important to the diesel combustion process. The PCM
monitors outputs from the engine speed sensor (fly-
wheel position in degrees), and the fuel injector sen-
sor (mechanical movement within the #1 cylinder
fuel injector). Outputs from the Accelerator Pedal
Position sensor, engine speed sensor (engine rpm)
and engine coolant temperature sensor are also used.
The PCM will then compare its set values to these
outputs to electrically adjust the amount of fuel tim-
ing (amount of advance) within the injection pump.
This is referred to as ªClosed Loopº operation. The
PCM monitors fuel timing by comparing its set value
to when the injector #1 opens. If the value is greater
than a preset value a fault will be set.
Fig. 4 Fuel Shutdown Solenoid and Overflow Valve
Location
Fig. 5 Fuel Injection Pump
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 5
DESCRIPTION AND OPERATION (Continued)