fuel injection CHRYSLER VOYAGER 1996 Workshop Manual

KNOCK SENSORÐPCM INPUTÐ2.0L ENGINE
Refer to the Knock Sensor 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.
MANIFOLD ABSOLUTE PRESSURE (MAP
SENSOR)ÐPCM INPUTÐ2.0L ENGINE
Refer to the Manifold Absolute Pressure and
Intake Air Temperature sensors 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.
SPEED CONTROLÐPCM INPUTÐ2.0L ENGINE
Refer to the Speed Control 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.
Fig. 3 Engine Coolant Temperature SensorÐ2.0L
engine
Fig. 4 Upstream Heated Oxygen SensorÐ2.0L
Engine
Fig. 5 Downstream Heated Oxygen SensorÐ2.0L
Engine
Fig. 6 Knock SensorÐ2.0L engine
Fig. 7 MAP/IAT sensorÐ2.0L engine
14 - 34 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
DESCRIPTION AND OPERATION (Continued)

THROTTLE POSITION SENSOR/ IDLE AIR
CONTROL MOTORÐPCM INPUTÐ2.0L ENGINE
Refer to the Throttle Control and Idle Air Control
motor for the 2.4/3.0/3.3/3.8L engines under Descrip-
tion and Operation in the Fuel Injection System sec-
tion of group 14 for more information.
AIR CONDITIONING (A/C) RELAYÐPCM
OUTPUTÐ2.0L ENGINE
Refer to the Air Conditioning relay 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.
GENERATOR FIELDÐPCM OUTPUTÐ2.0L ENGINE
Refer to Generator Field 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.
AUTOMATIC SHUTDOWN RELAYÐPCM
OUTPUTÐ2.0L ENGINE
Refer to Automatic Shutdown Relay 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.
FUEL PUMP RELAYÐPCM OUTPUTÐ2.0L ENGINE
Refer to the Fuel Pump Relay 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.
STARTER RELAYÐPCM OUTPUTÐ2.0L ENGINE
Refer to the Starter Relay 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.
IDLE AIR CONTROL MOTORÐPCM OUTPUTÐ2.0L
ENGINE
Refer to the Idle Air Control Motor 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. Refer to (Fig. 8) for component location
ELECTRONIC EGR TRANSDUCERÐPCM
OUTPUTÐ2.0L ENGINE
Refer to the Electronic EGR Transducer 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.
DATA LINK CONNECTORÐPCM OUTPUTÐ2.0L
ENGINE
Refer to the Data Link Connector 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.
FUEL INJECTORSÐPCM OUTPUTÐ2.0L ENGINE
Refer to the Fuel Injectors 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.
Fig. 8 Throttle Position Sensor/Idle Air Control
motorÐ2.0L engine
Fig. 9 Electronic EGR TransducerÐ2.0L engine
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 35
DESCRIPTION AND OPERATION (Continued)

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)

(20) Inspect the electrical connections at the
upstream and downstream heated oxygen sensors
(Fig. 25) and (Fig. 26).
(21) Inspect the fuel pump module electrical con-
nection at the fuel tank for corrosion or damage (Fig.27). Check for pinched, kinked or damaged fuel sup-
ply tube.
(22) Inspect the connections to the speed control
servo, if equipped. Refer to Group 8H, Vehicle Speed
Control.
(23) Inspect the connection at the battery temper-
ature sensor.
ASD AND FUEL PUMP RELAYSÐ2.0L ENGINE
Refer to the ASD and Fuel Pump Relays for 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.
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSORÐ2.0L ENGINE
To perform a complete test of the MAP sensor and
its circuitry, refer to the DRB scan tool and appropri-
ate Powertrain Diagnostics Procedures manual. To
test the MAP sensor only, refer to the following:
Fig. 23 Vehicle Speed Sensor
Fig. 24 Power Steering Pressure Switch
Fig. 25 Upstream Heated Oxygen Sensor
Fig. 26 Downstream Heated Oxygen Sensor
Fig. 27 Fuel Pump Module Electrical Connector
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 39
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)

FUEL INJECTION SYSTEMÐ2.5L DIESEL ENGINE
INDEX
page page
GENERAL INFORMATION
INTRODUCTION....................... 43
DESCRIPTION AND OPERATION
AIR CONDITIONING (A/C) CONTROLSÐ
PCM INPUTS........................ 47
AIR CONDITIONING RELAYÐPCM OUTPUT . . 48
BATTERY VOLTAGEÐPCM INPUT.......... 45
BOOST PRESSURE SENSOR............. 45
BRAKE SWITCHÐPCM INPUT............. 47
DATA LINK CONNECTORÐ
PCM INPUT AND OUTPUT.............. 47
DIESEL PCM RELAYÐPCM INPUT......... 48
ENGINE COOLANT GAUGEÐPCM OUTPUT . . 48
ENGINE COOLANT TEMPERATURE SENSORÐ
PCM INPUT......................... 46
ENGINE OIL PRESSURE GAUGEÐ
PCM OUTPUT........................ 48
ENGINE SPEED SENSORÐPCM INPUT..... 46
EXHAUST GAS RECIRCULATION (EGR)
SOLENOIDÐPCM OUTPUT............. 50
FIVE VOLT POWERÐPCM OUTPUT........ 48
FUEL INJECTOR SENSORÐGROUND...... 46
FUEL TIMING SOLENOIDÐPCM OUTPUT.... 48
GLOW PLUG LAMPÐPCM OUTPUT........ 48
GLOW PLUG RELAYÐPCM OUTPUT....... 49
GLOW PLUGS......................... 49
IGNITION CIRCUIT SENSEÐPCM INPUT.... 45
NEEDLE MOVEMENT OR INSTRUMENTED
FIRST INJECTORÐPCM INPUT.......... 45
POWER GROUND...................... 45
POWERTRAIN CONTROL MODULE (PCM) . . . 44
SENSOR RETURNÐPCM INPUT (ANALOG
GROUND)........................... 45SIGNAL GROUNDÐPCM INPUT........... 45
SPEED CONTROLÐPCM INPUTS.......... 48
SPEED CONTROLÐPCM OUTPUTS........ 48
START SIGNALÐPCM INPUT............. 45
TACHOMETERÐPCM OUTPUT............ 49
VEHICLE SPEED SENSORÐPCM INPUT.... 47
VEHICLE THEFT ALARM................. 45
DIAGNOSIS AND TESTING
BOOST PRESSURE SENSOR............. 53
DIAGNOSTIC TROUBLE CODES........... 53
DIESEL DIAGNOSTICS.................. 50
DIESEL PCM RELAY TEST............... 50
ENGINE COOLANT TEMPERATURE
SENSOR TEST....................... 50
ENGINE SPEED SENSOR TEST........... 50
GLOW PLUG RELAY TEST............... 51
GLOW PLUG TEST..................... 51
RELAYSÐOPERATION/TESTING........... 52
VEHICLE SPEED SENSOR TEST........... 53
REMOVAL AND INSTALLATION
A/C CLUTCH RELAY.................... 53
DIESEL PCM RELAY.................... 53
ENGINE COOLANT TEMPERATURE
SENSOR............................ 54
ENGINE SPEED SENSOR................ 53
GLOW PLUG RELAY.................... 55
GLOW PLUGS......................... 54
POWERTRAIN CONTROL MODULE (PCM) . . . 55
VEHICLE SPEED SENSOR............... 55
SPECIFICATIONS
GLOW PLUG CURRENT DRAW............ 56
TORQUE CHARTÐ2.5L DIESEL............ 57
GENERAL INFORMATION
INTRODUCTION
This section will cover components either regulated
or controlled by the Powertrain Control Module
(PCM). The fuel heater relay, fuel heater and fuel
gauge are not operated by the PCM. These compo-
nents 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. Refer to the following PCM description for
more information.
Certain fuel system component failures may cause
a no start, or prevent the engine from running. It is
important to know that the PCM has a featurewhere, if possible, it will ignore the failed sensor, set
a code related to the sensor, and operate the engine
in a ªLimp Homeº mode. When the PCM is operating
in a ªLimp Homeº mode, the Diesel Glow Plug lamp
on the instrument panel will be constantly illumi-
nated, and the engine will most likely have a notice-
able loss of performance. An example of this would be
an Accelerator Pedal Position Sensor failure, and in
that situation, the engine would run at a constant
1100 RPM, regardless of the actual position of the
pedal. This is the most extreme of the three ªLimp
Homeº modes.
In addition to indicating that the glow plugs are
hot enough to start combustion, the Glow Plug Lamp
is also used in the diagnosis of the PCM, and when
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 43

BOOST PRESSURE SENSOR
The Boost Pressure Sensor is mounted to the top of
the intake manifold. (Fig. 2) It is a sensor that mea-
sures both manifold vacuum and turbo boost, and it
also contains an integrated intake air temperature
sensor. The Boost Pressure Sensor takes the place of
the Mass Air Flow (MAF). In the Intake Air Temper-
ature Sensor component, there is a ceramic element
that changes its resistance based on temperature.
The ceramic element is part of an electronic circuit
connected to the PCM, and has a voltage applied to
it. The ceramic element is exposed to the air inside
the intake. This air has a cooling effect on the
ceramic element, and its resistance changes. This
causes the voltage flowing through the intake air
temperature circuit to vary. The voltage signal pro-
duced by the Intake Air Temperature Sensor changes
inversely to the temperature, and is measured by the
PCM. As a general rule, when the temperature of the
air in the intake is high, the voltage signal produced
by the Intake Air Temperature Sensor is low. The
component of the Boost Pressure Sensor that mea-
sures manifold vacuum and turbo boost produces a
voltage signal that is proportional to the pressure in
the inake manifold. When the intake manifold pres-
sure is low, the voltage is low, and when the pressure
is high, the voltage is high. The PCM uses the volt-
age signals from the Boost Pressure Sensor, and the
Intake Air Temperature Sensor to determine the
amount of air flowing through the intake manifold.
VEHICLE THEFT ALARM
The PCM can learn if the vehicle has a Vehicle
Theft Alarm (VTA) system. Once it detects the vehi-
cle having VTA,the controller can ONLY BE
USED ON VEHICLES WITH VTA.If the PCM is put it on a vehicle without VTA the
Glow Plug Lamp will start to blink and the vehicle
will not start.
The PCM cannot be flashed to remove the VTA.
BATTERY VOLTAGEÐPCM INPUT
The battery voltage input provides power to the
PCM. It also informs the PCM what voltage level is
being supplied by the generator once the vehicle is
running.
The battery input also provides the voltage that is
needed to keep the PCM memory alive. The memory
stores Diagnostic Trouble Code (DTC) messages.
Trouble codes will still be stored even if the battary
voltage is lost.
SENSOR RETURNÐPCM INPUT (ANALOG
GROUND)
Sensor Return provides a low noise Analog ground
reference for all system sensors.
SIGNAL GROUNDÐPCM INPUT
Signal ground provides a low noise ground to the
data link connector.
IGNITION CIRCUIT SENSEÐPCM INPUT
The ignition circuit sense input signals the PCM
that the ignition (key) switch has been turned to the
ON position. This signal initiates the glow plug con-
trol routine to begin the ªpre±heatº cycle.
START SIGNALÐPCM INPUT
This input tells the PCM that the engine starter is
being operated. This in turn will start the glow plug
ªpost±heatº cycle.
POWER GROUND
Provides a common ground for power devices (sole-
noid and relay devices).
NEEDLE MOVEMENT OR INSTRUMENTED FIRST
INJECTORÐPCM INPUT
This input from the PCM supplies a constant 30
mA electrical current source for the first injector sen-
sor. It will vary the voltage to this sensor when it
senses a mechanical movement within the injector
needle (pintle) of the number±1 cylinder fuel injector.
When this voltage has been determined by the PCM,
it will then control an output to the fuel timing sole-
noid (the fuel timing solenoid is located on the fuel
injection pump). Also refer to Fuel Injection Pump for
additional information.
The first injector sensor is a magnetic (inductive)
type.
Fig. 2 Boost Pressure Sensor Location
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 45
DESCRIPTION AND OPERATION (Continued)

The first injector sensor is used only on the fuel
injector for the number±1 cylinder (Fig. 3). It is not
used on the injectors for cylinders number 2, 3, or 4.
FUEL INJECTOR SENSORÐGROUND
Provides a low noise ground for the fuel injector
sensor only.
ENGINE COOLANT TEMPERATURE SENSORÐPCM
INPUT
The 0±5 volt input from this sensor tells the PCM
the temperature of the engine coolant. Based on the
voltage received at the PCM, it will then determine
operation of the fuel timing solenoid, glow plug relay,
electrical vacuum modulator (emission component)
and generator (charging system).
The sensor is located on the side of the #3 cylinder
head near the rear of fuel injection pump (Fig. 4).
ENGINE SPEED SENSORÐPCM INPUT
The engine speed sensor is mounted to the trans-
mission bellhousing at the left/rear side of the engine
block (Fig. 5).
The engine speed sensor produces its own output
signal. If this signal is not received the engine will
not start by the PCM.
The engine speed sensor input is used in conjunc-
tion with the first injector sensor to establish fuel
injection pump timing.
The flywheel has four notches at its outer edge
(Fig. 6). Each notch is spaced equally every 90É. The
notches cause a pulse to be generated when they
pass under the speed sensor (Fig. 6). These pulses
are the input to the PCM. The input from this sensor
determines crankshaft position (in degrees) by moni-
toring the notches.The sensor also generates an rpm signal to the
PCM. This signal is used as an input for the Diesel
relay for control of the generator field, vehicle speed
control, and instrument panel mounted tachometer.
If the engine speed sensor should fail, the system
is unable to compensate for the problem and the car
will stop.
Fig. 3 Fuel Injector Sensor
Fig. 4 Engine Coolant Temperature Sensor Location
Fig. 5 Engine Speed Sensor Location
14 - 46 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
DESCRIPTION AND OPERATION (Continued)

The speed sensor generates 8 pulses per sensor
revolution. These signals, in conjunction with a
closed throttle signal from the throttle position sen-
sor, indicate a closed throttle deceleration to the
PCM. When the vehicle is stopped at idle, a closed
throttle signal is received by the PCM (but a speed
sensor signal is not received).
In addition to determining distance and vehicle
speed, the output from the sensor is used to control
speed control operation.
SPEED CONTROLÐPCM INPUTS
The speed control system provides five separate
inputs to the PCM; On/Off, Set, Resume/Accel, Cancel,
and Decel.. The On/Off input informs the PCM that
the speed control system has been activated. The Set
input informs the PCM that a fixed vehicle speed has
been selected. The Resume input indicates to the PCM
that the previous fixed speed is requested.
Speed control operation will start at 50 km/h±142
km/h (35±85 mph). The upper range of operation is
not restricted by vehicle speed. Inputs that affect
speed control operation are vehicle speed sensor and
throttle position sensor.
Refer to Group 8H for further speed control infor-
mation.
DIESEL PCM RELAYÐPCM INPUT
A 12 volt signal at this input indicates to the PCM
that the Diesel relay has been activated. The Diesel
relay is located in the PDC. The PDC is located next
to the battery in the engine compartment. For the
location of the relay within the PDC, refer to label on
PDC cover.
This input is used only to sense that the Diesel
relay is energized. If the PCM does not see 12 volts +
at this input when the Diesel relay should be acti-
vated, it will set a Diagnostic Trouble Code (DTC).
FIVE VOLT POWERÐPCM OUTPUT
This circuit supplies approximately 5 volts to
power the Accelerator Pedal Postion Sensor, Mass Air
Flow Sensor, and A/C Pressure Sensor.
ENGINE COOLANT GAUGEÐPCM OUTPUT
Refer to the Instrument Panel and Gauges group
for additional information.
ENGINE OIL PRESSURE GAUGEÐPCM OUTPUT
Refer to the Instrument Panel and Gauges group
for additional information.
GLOW PLUG LAMPÐPCM OUTPUT
The Glow Plug lamp (malfunction indicator lamp)
illuminates on the message center each time the igni-
tion (key) switch is turned on. It will stay on for
about two seconds as a bulb test.If the PCM receives an incorrect signal, or no sig-
nal from certain sensors or components, the lamp
BLINKS. This is a warning that the PCM has
recorded a system or sensor malfunction. It signals
an immediate need for service. There are only 5
HARD faults that can turn on this lamp to make it
blink.
SPEED CONTROLÐPCM OUTPUTS
These two circuits control the fuel quantity actua-
tor to regulate vehicle speed. Refer to Group 8H for
Speed Control information.
AIR CONDITIONING RELAYÐPCM OUTPUT
This circuit controls a ground signal for operation
of the A/C clutch relay. Also refer to Air Conditioning
(A/C) ControlsÐPCM Input for additional informa-
tion.
The A/C relay is located in the Power Distribution
Center (PDC). The PDC is located next to the battery
in the engine compartment. For the location of the
relay within the PDC, refer to label on PDC cover.
FUEL TIMING SOLENOIDÐPCM OUTPUT
The fuel timing solenoid is located on the bottom of
the fuel injection pump (Fig. 10).
This 12+ volt, pulse width modulated (duty±cycle)
output controls the amount of fuel timing (advance)
in the fuel injection pump. The higher the duty-
Fig. 9 Glow Plug Lamp Symbol
Fig. 10 Fuel Timing Solenoid
14 - 48 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
DESCRIPTION AND OPERATION (Continued)

the current draw will drop to approximately 9±12
amps per plug.
Total momentary current draw for all four plugs is
approximately 100 amps on a cold engine dropping to
a total of approximately 40 amps after the plugs are
heated.
Electrical operation of the glow plugs are con-
trolled by the glow plug relay. Refer to the previous
Glow Plug RelayÐPCM Output for additional infor-
mation.
EXHAUST GAS RECIRCULATION (EGR)
SOLENOIDÐPCM OUTPUT
This circuit controls operation of the Exhaust Gas
Recirculation (EGR) solenoid. The EGR solenoid (Fig.
11) controls operation of the EGR valve.
Refer to Group 25, Emission Control System for
information. See EGR solenoid.
DIAGNOSIS AND TESTING
DIESEL DIAGONSTICS
The PCM controller does engine off diagonstics
tests, which may be heard for about 60 seconds after
turning the key off.
DIESEL PCM RELAY TEST
To perform a test of the relay and its related cir-
cuitry, refer to the DRB scan tool. To test the relay
only, refer to RelaysÐOperation/Testing in this sec-
tion of the group.
Diagnostic Trouble Codes:Refer to On-Board
Diagnostics in Group 25, Emission Control System
for a list of Diagnostic Trouble Codes (DTC's) for cer-
tain fuel system components.
ENGINE SPEED SENSOR TEST
To perform a test of the engine speed sensor and
its related circuitry, refer to the DRB scan tool.
Diagnostic Trouble Codes:Refer to On-Board
Diagnostics in Group 25, Emission Control System
for a list of Diagnostic Trouble Codes (DTC's) for cer-
tain fuel system components.
ENGINE COOLANT TEMPERATURE SENSOR TEST
The sensor is located on the side of cylinder head
near the rear of fuel injection pump (Fig. 13).
For a list of Diagnostic Trouble Codes (DTC's) for
certain fuel system components, refer to On-Board
Diagnostics in Group 25, Emission Control System.
To test the sensor only, refer to the following:
(1) Disconnect wire harness connector from coolant
temperature sensor.
(2) Test the resistance of the sensor with a high
input impedance (digital) volt±ohmmeter. The resis-
tance (as measured across the sensor terminals)should be less than 1340 ohms with the engine
warm. Refer to the following Sensor Resistance
(OHMS) chart. Replace the sensor if it is not within
the range of resistance specified in the chart.
(3) Test continuity of the wire harness. Do this
between the PCM wire harness connector and the
sensor connector terminal. Also test continuity of
wire harness to the sensor connector terminal. Refer
Fig. 13 Engine Coolant Temperature Sensor
Location
SENSOR RESISTANCE (OHMS)
14 - 50 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
DESCRIPTION AND OPERATION (Continued)