ignition CHRYSLER VOYAGER 1996 Service Manual

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)

FUEL HEATER
The fuel heater is used to prevent diesel fuel from
waxing during cold weather operation. The fuel
heater is located in the bottom plastic bowl of the
fuel filter/water separator (Fig. 10).
The element inside the heater assembly is made of
a Positive Temperature Coefficient (PTC) material,
and has power applied to it by the fuel heater relayanytime the ignition key is in the ªonº position. PTC
material has a high resistance to current flow when
its temperature is high, which means that it will not
generate heat when the temperature is above a cer-
tain value. When the temperature is below 7ÉC (45É
F), the resistance of the PTC element is lowered, and
allows current to flow through the fuel heater ele-
ment warming the fuel. When the temperature is
above 29ÉC (85É F), the PTC element's resistance
rises, and current flow through the heater element
stops.
Voltage to operate the fuel heater is supplied from
the ignition (key) switch and through the fuel heater
relay. Refer to the following Fuel Heater Relay for
additional information.The fuel heater and fuel
heater relay are not controlled by the Power-
train Control Module (PCM).
Current draw for the heater element is 150 watts
at 14 volts (DC).
FUEL HEATER RELAY
Voltage to operate the fuel heater is supplied from
the ignition (key) switch through the fuel heater
relay.The PCM is not used to control this relay.
The fuel heater relay is located in the PDC. The
PDC is located next to the battery in the engine com-
partment (Fig. 11). For the location of the relay
within the PDC, refer to label on PDC cover.
WASTEGATE (TURBOCHARGER)
Refer to Group 11, Exhaust System and Intake
Manifold for information.
Fig. 9 Fuel Drain Tubes
Fig. 10 Fuel Heater Temperature Sensor and
Element LocationFig. 11 Relay Location
14 - 8 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
DESCRIPTION AND OPERATION (Continued)

A defective fuel injection pump, defective fuel tim-
ing solenoid or misadjusted mechanical pump timing
can cause starting problems or prevent the engine
from revving up. It can also cause:
²Engine surge at idle
²Rough idle (warm engine)
²Low power
²Excessive fuel consumption
²Poor performance
²Low power
²Black smoke from the exhaust
²Blue or white fog like exhaust
²Incorrect idle or maximum speed
The electronically controlled fuel pump has no
mechanical governor like older mechanically con-
trolled fuel pumps. Do not remove the top cover of
the fuel pump, or the screws fastening the wiring
pigtail to the side of the pump.The warranty of
the injection pump and the engine may be void
if those seals have been removed or tampered
with.
FUEL SUPPLY RESTRICTIONS
LOW±PRESSURE LINES
Restricted or Plugged supply lines or fuel filter can
cause a timing fault that will cause the PCM to oper-
ate the engine in a ªLimp Homeº mode. See the
introduction of the Fuel Injection System in this
group for more information on the Limp Home mode.
Fuel supply line restrictions can cause starting prob-
lems and prevent the engine from revving up. The
starting problems include; low power and blue or
white fog like exhaust. Test all fuel supply lines for
restrictions or blockage. Flush or replace as neces-
sary. Bleed the fuel system of air once a fuel supply
line has been replaced. Refer to the Air Bleed Proce-
dure section of this group for procedures.
HIGH±PRESSURE LINES
Restricted (kinked or bent) high±pressure lines can
cause starting problems, poor engine performance
and black smoke from exhaust.
Examine all high±pressure lines for any damage.
Each radius on each high±pressure line must be
smooth and free of any bends or kinks.
Replace damaged, restricted or leaking high±pres-
sure fuel lines with the correct replacement line.
CAUTION: The high±pressure fuel lines must be
clamped securely in place in the holders. The lines
cannot contact each other or other components. Do
not attempt to weld high±pressure fuel lines or to
repair lines that are damaged. Only use the recom-
mended lines when replacement of high±pressure
fuel line is necessary.
FUEL SHUTDOWN SOLENOID TEST
Since diesel fuel injection does not use spark plugs
to start combustion, the only way to stop the engine
is to cut off the fuel supply. This is done with the
Fuel Shutdown Solenoid. If the engine cranks, but
refuses to start, it may be caused by a defective fuel
shutdown solenoid.
The fuel shutdown solenoid is not controlled
or operated by the PCM.Voltage to operate the
solenoid is supplied from the ignition (key) switch.
NOTE: Although the fuel shutdown solenoid is not
operated by the PCM, if the Fuel Shutdown Solenoid
has been disconnected, and the key turned on, the
PCM will sense that the solenoid is not in the circuit,
and will switch to a ªLimp Homeº mode. After recon-
necting the solenoid, the PCM will have to be reset
by clearing the codes with the DRBIII scan tool, or
disconnecting the vehicle's battery for several min-
utes. The DRBIII scan tool is the preferred method
for resetting the PCM. Refer to the 1998 GS 2.5L Die-
sel Powertrain Diagnostic Manual for procedure.
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. 23).
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 sole-
noid is shut off and fuel flow is not allowed to the fuel
injection pump. When the key is placed in the ON or
Fig. 23 Fuel Shutdown Solenoid Location
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 13
DIAGNOSIS AND TESTING (Continued)

START positions, fuel supply is allowed at the injec-
tion pump.
(1) Disconnect the electrical pigtail connector (test
connector) (Fig. 23) from the main engine wiring har-
ness. Do not disconnect wiring directly at solenoid.
(2) Connect the leads of a voltmeter between a
good ground and the disconnected engine wiring har-
ness.
(3) Turn the key to the ON position. Do not
attempt to start engine.
(4) 12V+ should be observed at wiring harness. If
not, refer to Group 8, Wiring for wiring schematics
and repair as necessary.
(5) T
urn the key to the START position. 12V+ should
be observed at wiring harness. If not, refer to Group 8,
Wiring for wiring schematics and repair as necessary.
The fault may be in the ignition (key) switch.
12V+ must be observed in both the ON and START
positions. If 12V+ was observed, proceed to the next
step.
(6) With key still in the ON position, connect and
disconnect the wiring harness to the solenoid. As this
is done, a clicking noise should be heard coming from
the solenoid. If not, replace solenoid. Refer to Fuel
Shutdown Solenoid in the Removal/Installation sec-
tion of this group for procedures.
HIGH-PRESSURE FUEL LINE LEAK TEST
High±pressure fuel line leaks can cause starting
problems and poor engine performance.
WARNING: DUE TO EXTREME FUEL PRESSURES
OF UP TO 45,000 KPA (6526 PSI), USE EXTREME
CAUTION WHEN INSPECTING FOR HIGH±PRESSURE
FUEL LEAKS. DO NOT GET YOUR HAND, OR ANY
PART OF YOUR BODY NEAR A SUSPECTED LEAK.
INSPECT FOR HIGH±PRESSURE FUEL LEAKS WITH
A SHEET OF CARDBOARD. HIGH FUEL INJECTION
PRESSURE CAN CAUSE PERSONAL INJURY IF
CONTACT IS MADE WITH THE SKIN.
Start the engine. Move the cardboard over the
high±pressure fuel lines and check for fuel spray onto
the cardboard (Fig. 24). If a high±pressure line con-
nection is leaking, bleed the system and tighten the
connection. Refer to the Air Bleed Procedure in this
group for procedures. Replace damaged, restricted or
leaking high±pressure fuel lines with the correct
replacement line.
CAUTION: The high±pressure fuel lines must be
clamped securely in place in the holders. The lines
cannot contact each other or other components. Do
not attempt to weld high±pressure fuel lines or to
repair lines that are damaged. Only use the recom-
mended lines when replacement of high±pressure
fuel line is necessary.
WASTEGATE (TURBOCHARGER)
Refer to Group 11, Exhaust System and Intake
Manifold for information.
SERVICE PROCEDURES
AIR BLEED PROCEDURES
AIR BLEEDING AT FUEL FILTER
A certain amount of air may become trapped in the
fuel system when fuel system components are ser-
viced or replaced. Bleed the system as needed after
fuel system service according to the following proce-
dures.
WARNING: DO NOT BLEED AIR FROM THE FUEL
SYSTEM OF A HOT ENGINE. DO NOT ALLOW FUEL
TO SPRAY ONTO THE EXHAUST MANIFOLD WHEN
BLEEDING AIR FROM THE FUEL SYSTEM.
Some air enters the fuel system when the fuel fil-
ter or injection pump supply line is changed. This
small amount of air is vented automatically from the
injection pump through the fuel drain manifold tubes
if the filter was changed according to instructions.
Ensure the bowl of the fuel filter/water separator is
full of fuel
It may be necessary to manually bleed the system
if:
²The bowl of the fuel filter/water separator is not
partially filled before installation of a new filter
²The injection pump is replaced
Fig. 24 Typical Test for Leaks with Cardboard
14 - 14 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
DIAGNOSIS AND TESTING (Continued)

(7) Connect fuel supply tube to fuel rail. Refer to
Quick Connect Fittings in the Fuel Delivery Section
of this Group.
ACCELERATOR PEDAL
Refer to the Accelerator Pedal for the 2.4/3.0/.3.3/
3.8L engines under Removal and Installation in the
Fuel Delivery section of group 14 for more informa-
tion.
TORQUE SPECIFICATION
DESCRIPTION TORQUE
Accelerator Pedal to
Dash Nuts..............12N´m(105 in. lbs.)
Fuel Pump Module Locknut....58N´m(43ft.lbs.)
Fuel Tank Strap Bolts.........54N´m(40ftlbs.)
Fuel Rail Bolts.............23N´m(195 in. lbs.)
Ignition Coil Mounting Bolts . . . 11 N´m (95 in. lbs.)
Intake Manifold Bolts........11N´m(95in.lbs.)
Throttle Control Shield.......5.6N´m(50in.lbs.)
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 31
REMOVAL AND INSTALLATION (Continued)

FUEL INJECTION SYSTEMÐ2.0L ENGINE
INDEX
page page
GENERAL INFORMATION
INTRODUCTIONÐ2.0L ENGINE............ 32
MODES OF OPERATIONÐ2.0L ENGINE..... 32
DESCRIPTION AND OPERATION
AIR CONDITIONING (A/C) RELAYÐPCM
OUTPUTÐ2.0L ENGINE................ 35
AIR CONDITIONING PRESSURE
TRANSDUCERÐPCM INPUTÐ
2.0L ENGINE......................... 33
AIR CONDITIONING SWITCH SENSEÐ
PCM INPUTÐ2.0L ENGINE.............. 33
AUTOMATIC SHUTDOWN (ASD) SENSEÐ
PCM INPUTÐ2.0L ENGINE.............. 33
AUTOMATIC SHUTDOWN RELAYÐ
PCM OUTPUTÐ2.0L ENGINE............ 35
BATTERY VOLTAGEÐPCM INPUTÐ
2.0L ENGINE......................... 33
CAMSHAFT POSITION SENSORÐ
PCM INPUTÐ2.0L ENGINE.............. 33
CRANKSHAFT POSITION SENSORÐ
PCM INPUTÐ2.0L ENGINE.............. 33
DATA LINK CONNECTORÐPCM OUTPUTÐ
2.0L ENGINE......................... 35
ELECTRONIC EGR TRANSDUCERÐ
PCM OUTPUTÐ2.0L ENGINE............ 35
ENGINE COOLANT TEMPERATURE SENSORÐ
PCM INPUTÐ2.0L ENGINE.............. 33
FUEL INJECTORSÐPCM OUTPUTÐ
2.0L ENGINE......................... 35
FUEL PUMP RELAYÐPCM OUTPUTÐ
2.0L ENGINE......................... 35
GENERATOR FIELDÐPCM OUTPUTÐ
2.0L ENGINE......................... 35
HEATED OXYGEN SENSORÐPCM INPUTÐ
2.0L ENGINE......................... 33
IDLE AIR CONTROL MOTORÐPCM OUTPUTÐ
2.0L ENGINE......................... 35
IGNITION COILÐPCM OUTPUTÐ
2.0L ENGINE......................... 36KNOCK SENSORÐPCM INPUTÐ
2.0L ENGINE......................... 34
MALFUNCTION INDICATOR (CHECK ENGINE)
LAMPÐPCM OUTPUTÐ2.0L ENGINE...... 36
MANIFOLD ABSOLUTE PRESSURE
(MAP SENSOR)ÐPCM INPUTÐ
2.0L ENGINE......................... 34
POWERTRAIN CONTROL MODULEÐ
2.0L ENGINE......................... 33
RADIATOR FAN CONTROL MODULEÐ
PCM OUTPUTÐ2.0L ENGINE............ 36
SPEED CONTROL SOLENOIDSÐ
PCM OUTPUTÐ2.0L ENGINE............ 36
SPEED CONTROLÐPCM INPUTÐ
2.0L ENGINE......................... 34
STARTER RELAYÐPCM OUTPUTÐ
2.0L ENGINE......................... 35
SYSTEM DIAGNOSISÐ2.0L ENGINE........ 33
TACHOMETERÐPCM OUTPUTÐ
2.0L ENGINE......................... 36
THROTTLE BODYÐ2.0L ENGINE.......... 36
THROTTLE POSITION SENSOR/ IDLE AIR
CONTROL MOTORÐPCM INPUTÐ
2.0L ENGINE......................... 35
DIAGNOSIS AND TESTING
ASD AND FUEL PUMP RELAYSÐ
2.0L ENGINE......................... 39
CAMSHAFT AND CRANKSHAFT
POSITION SENSOR................... 40
ENGINE COOLANT TEMPERATURE
SENSOR............................ 40
KNOCK SENSORÐ2.0L ENGINE........... 40
MANIFOLD ABSOLUTE PRESSURE
(MAP) SENSORÐ2.0L ENGINE........... 39
THROTTLE BODY MINIMUM AIR FLOW..... 41
THROTTLE POSITION SENSOR........... 40
VISUAL INSPECTIONÐSOHC............. 36
SPECIFICATIONS
TORQUE............................. 42
GENERAL INFORMATION
INTRODUCTIONÐ2.0L ENGINE
Refer to the Introduction for 2.4/3.0/3.3/3.8L
engines under General Information in the Fuel Injec-
tion System section of group 14 for more information.
MODES OF OPERATIONÐ2.0L ENGINE
Refer to the Modes of Operation for 2.4/3.0/3.3/3.8L
engines under General Information in the Fuel Injec-
tion System section of group 14 for more information.
14 - 32 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS

IGNITION COILÐPCM OUTPUTÐ2.0L ENGINE
Refer to the Ignition Coil for 2.4/3.0/3.3/3.8L
engines under Description and Operation in the Fuel
Injection System section of group 14 for more infor-
mation.
MALFUNCTION INDICATOR (CHECK ENGINE)
LAMPÐPCM OUTPUTÐ2.0L ENGINE
Refer to the Malfunction Indicator Lamp for 2.4/
3.0/3.3/3.8L engines under Description and Operation
in the Fuel Injection System section of group 14 for
more information.
RADIATOR FAN CONTROL MODULEÐPCM
OUTPUTÐ2.0L ENGINE
Refer to the Radiator Fan Control Module for 2.4/
3.0/3.3/3.8L engines under Description and Operation
in the Fuel Injection System section of group 14 for
more information.
SPEED CONTROL SOLENOIDSÐPCM OUTPUTÐ
2.0L ENGINE
Refer to the Speed Control Solenoids for 2.4/3.0/3.3/
3.8L engines under Description and Operation in the
Fuel Injection System section of group 14 for more
information.
TACHOMETERÐPCM OUTPUTÐ2.0L ENGINE
Refer to the Tachometer for 2.4/3.0/3.3/3.8L engines
under Description and Operation in the Fuel Injec-
tion System section of group 14 for more information.
THROTTLE BODYÐ2.0L ENGINE
Refer to the Throttle Body for 2.4/3.0/3.3/3.8L
engines under Description and Operation in the Fuel
Injection System section of group 14 for more infor-
mation.
DIAGNOSIS AND TESTING
VISUAL INSPECTIONÐSOHC
Before diagnosing or servicing the fuel injection
system, perform a visual inspection for loose, discon-
nected, or misrouted wires and hoses. A thorough
visual inspection that includes the following checks
saves unnecessary test and diagnostic time.
(1) Inspect the battery connections. Clean corroded
terminals.
(2) Check the 2 PCM 40-way connector for
stretched wires on pushed out terminals
(3) Open the Power Distribution Center (PDC).
Check for blown fuses. Ensure the relays and fuses
are fully seated in the PDC. A label on the underside
of the PDC cover shows the locations of each relay
and fuse.
(4) Verify the throttle cable operates freely.
(5) Check the electrical connections at the idle air
control motor and throttle position sensor.
(6) Check hose connections between the PCV
valve, vacuum port - intake manifold and the oil sep-
arator (Fig. 13).
(7) Inspect the electrical connections at the MAP
sensor/intake air temperature sensor and the (Fig.
14).
(8) Inspect the fuel injector electrical connections
(Fig. 15).
(9) Inspect the ignition coil electrical connector.
Ensure the spark plug insulators are firmly seated
over the spark plugs (Fig. 16).
(10) Check the electrical connection to the radiator
fan.
(11) Inspect for corrosion on the electrical connec-
tions at the starter motor solenoid. Check the ground
cable connection below the starter motor (Fig. 17).
(12) Inspect the air cleaner filter element. Replace
as necessary. Check the air induction system for
restrictions.
Fig. 10 Ignition CoilÐ2.0L engine
Fig. 11 Throttle BodyÐ2.0L engine
14 - 36 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
DESCRIPTION AND OPERATION (Continued)

(13) Check the electrical connection at the knock
sensor (Fig. 18).
(14) Check the electrical connections at the cam-
shaft position sensor and engine coolant temperature
sensor (Fig. 19).
(15) Check the electrical connector at the Elec-
tronic EGR Transducer. Inspect the vacuum and back
pressure hoses at the solenoid and transducer for
leaks (Fig. 20).
(16) Inspect the electrical connections at the gen-
erator (Fig. 21). Check the generator belt for glazing
or damage.(17) Inspect the electrical connector at the crank-
shaft position sensor (Fig. 22).
(18) Check the electrical connection at the vehicle
speed sensor (Fig. 23).
Fig. 12 Idle Air Control Motor and Throttle Position
SensorÐTypical
Fig. 13 PCV Valve
Fig. 14 MAP/Intake Air Temperature Sensor
Fig. 15 Fuel Injectors
Fig. 16 Ignition Coil and Spark PlugsÐTypical
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 37
DIAGNOSIS AND TESTING (Continued)

CAUTION: When testing the MAP sensor, be sure
that the harness wires are not damaged by the test
meter probes.
(1) Test the MAP sensor output voltage at the
MAP sensor connector between terminals 1 and 4
(Fig. 29). With the ignition switch ON and the engine
not running, output voltage should be 4 to 5 volts.
The voltage should drop to 1.5 to 2.1 volts with a hot,
neutral idle speed condition. If OK, go to next step. If
not OK, go to step 3.
(2) Test PCM terminal 36 for the same voltage
described in the previous step to verify wire harness
condition. Repair as required.(3) Test the MAP sensor ground circuit at sensor
connector terminal 1 and PCM terminal 43. If OK, go
to next step. If not OK, repair as required.
(4) Test MAP sensor supply voltage between sen-
sor connector terminals 3 and 1 with the key ON.
The voltage should be approximately 5 volts (6.5V).
Five volts (6.5V) should also be at terminal 61 of the
PCM. If OK, replace MAP sensor. If not OK, repair or
replace the wire harness as required.
KNOCK SENSORÐ2.0L ENGINE
The knock sensor output voltage to the PCM can
be read with the DRB III scan tool. Sensor output
should be between 80 mV and 4 volts with the engine
running between 576 and 2208 rpm. If the output
falls outside of this range a DTC will be set.
CAMSHAFT AND CRANKSHAFT POSITION SENSOR
Refer to Group 8D, Ignition for Diagnosis and Test-
ing of Camshaft and Crankshaft Sensors.
ENGINE COOLANT TEMPERATURE SENSOR
Refer to the Engine Coolant Temperature sensor
for the 2.4/3.0/3.3/3.8L engines under Diagnosis and
Testing in the Fuel Injection System section of group
14 for more information.
THROTTLE POSITION SENSOR
To perform a complete test of the this sensor and
its circuitry, the DRB III scan tool is the best
method. To test the throttle position sensor only,
refer to the following:
The Throttle Position Sensor (TPS) can be tested
with a digital voltmeter (DVM). The center terminal
of the sensor is the output terminal. One of the other
terminals is a 5 volt supply and the remaining ter-
minal is ground.
Fig. 28 ASD and Fuel Pump Relay Terminals
Fig. 29 MAP Sensor Connector
Fig. 30 Engine Coolant Temperature Sensor
LocationÐSOHC
14 - 40 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
DIAGNOSIS AND TESTING (Continued)