1996 CHRYSLER VOYAGER air conditioning

The PCM supplies approximately 5 volts to the
TPS. The TPS output voltage (input signal to the
PCM) represents the throttle blade position. The TPS
output voltage to the PCM varies from approximately
0.5 volt at minimum throttle opening (idle) to 4 volts
at wide open throttle. Along with inputs from other
sensors, the PCM uses the TPS input to determine
current engine operating conditions and adjust fuel
injector pulse width and ignition timing.
VEHICLE SPEED AND DISTANCEÐPCM INPUT
The transaxle output speed sensor supplies the
vehicle speed and distance inputs to the PCM. The
output speed sensor is located on the side of the tran-
saxle (Fig. 25).The speed and distance signals, along with a closed
throttle signal from the TPS, determine if a closed
throttle deceleration or normal idle condition (vehicle
stopped) exists. Under deceleration conditions, the
PCM adjusts the idle air control motor to maintain a
desired MAP value. Under idle conditions, the PCM
adjusts the idle air control motor to maintain a
desired engine speed.
INTAKE AIR TEMPERATURE SENSORÐPCM INPUT
(2.4L ONLY)
The Intake Air Temperature (IAT) sensor measures
the temperature of the intake air as it enters the
engine. The sensor supplies one of the inputs the
PCM uses to determine injector pulse width and
spark advance.
The IAT sensor threads into the intake manifold
(Fig. 29).
AIR CONDITIONING (A/C) CLUTCH RELAYÐPCM
OUTPUT
The PCM operates the air conditioning clutch relay
ground circuit. The radiator fan control module sup-
plies battery power to the solenoid side of the relay.
The air conditioning clutch relay will not energize
unless the radiator fan control module energizes. The
radiator control module energizes when the air con-
ditioning or defrost switch is put in the ON position
and the low pressure switch, combination valve, and
high pressure switch close.
With the engine operating, the PCM cycles the air
conditioning clutch on and off when the A/C switch
closes with the blower motor switch in the On posi-
tion. When the PCM senses low idle speeds or wide-
open-throttle through the throttle position sensor, it
de-energizes the A/C clutch relay. The relay contacts
open, preventing air conditioning clutch engagement.
The air conditioning clutch relay is located in the
Power Distribution Center (PDC). The PDC is located
Fig. 27 Throttle Position SensorÐ3.0L
Fig. 28 Throttle Position SensorÐ2.4L
Fig. 29 Intake Air Temperature Sensor
NSFUEL SYSTEM 14 - 41
DESCRIPTION AND OPERATION (Continued)

(brake, park/neutral, air conditioning). Deceleration
die out is also prevented by increasing airflow when
the throttle is closed quickly after a driving (speed)
condition.
DUTY CYCLE EVAP CANISTER PURGE
SOLENOIDÐPCM OUTPUT
The duty cycle EVAP purge solenoid regulates the
rate of vapor flow from the EVAP canister to the
throttle body. The PCM operates the solenoid.
During the cold start warm-up period and the hot
start time delay, the PCM does not energize the sole-
noid. When de-energized, no vapors are purged. The
PCM de-energizes the solenoid during open loop oper-
ation.
The engine enters closed loop operation after it
reaches a specified temperature and the time delay
ends. During closed loop operation, the PCM ener-
gizes and de-energizes the solenoid 5 or 10 times per
second, depending upon operating conditions. The
PCM varies the vapor flow rate by changing solenoid
pulse width. Pulse width is the amount of time the
solenoid energizes.
A rubber boot covers the duty cycle EVAP purge
solenoid. The solenoid attaches to a bracket mounted
to the right engine mount (Fig. 31). The top of the
solenoid has the word TOP on it. The solenoid will
not operate properly unless it is installed correctly.
PROPORTIONAL PURGE SOLENOID
All vehicles use a proportional purge solenoid. The
solenoid regulates the rate of vapor flow from theEVAP canister to the throttle body. The PCM oper-
ates the solenoid.
During the cold start warm-up period and the hot
start time delay, the PCM does not energize the sole-
noid. When de-energized, no vapors are purged.
The proportional purge solenoid operates at a fre-
quency of 200 hz and is controlled by an engine con-
troller circuit that senses the current being applied
to the proportional purge solenoid and then adjusts
that current to achieve the desired purge flow. The
proportional purge solenoid controls the purge rate of
fuel vapors from the vapor canister and fuel tank to
the engine intake manifold.
ELECTRONIC EGR TRANSDUCER SOLENOIDÐPCM
OUTPUT
The electronic EGR transducer contains an electri-
cally operated solenoid and a back-pressure trans-
ducer (Fig. 33) or (Fig. 34) or (Fig. 35). The PCM
operates the solenoid. The PCM determines when to
energize the solenoid. Exhaust system back-pressure
controls the transducer.
When the PCM energizes the solenoid, vacuum
does not reach the transducer. Vacuum flows to the
transducer when the PCM de-energizes the solenoid.
When exhaust system back-pressure becomes high
enough, it fully closes a bleed valve in the trans-
ducer. When the PCM de-energizes the solenoid and
back-pressure closes the transducer bleed valve, vac-
uum flows through the transducer to operate the
EGR valve.
De-energizing the solenoid, but not fully closing the
transducer bleed hole (because of low back-pressure),
varies the strength of vacuum applied to the EGR
valve. Varying the strength of the vacuum changes
the amount of EGR supplied to the engine. This pro-
Fig. 31 Duty Cycle EVAP Purge Solenoid
Fig. 32 Proportional Purge Solenoid
NSFUEL SYSTEM 14 - 43
DESCRIPTION AND OPERATION (Continued)

Shutdown (ASD) RelayÐPCM Output in this section
for relay operation.
TORQUE CONVERTER CLUTCH SOLENOIDÐPCM
OUTPUT
Three-speed automatic transaxles use a torque con-
verter clutch solenoid. The PCM controls the engage-
ment of the torque converter clutch through the
solenoid. The torque converter clutch is engaged only
in direct drive mode. Refer to Group 21 for transaxle
information.
MALFUNCTION INDICATOR (CHECK ENGINE)
LAMPÐPCM OUTPUT
The PCM supplies the malfunction indicator (check
engine) lamp on/off signal to the instrument panel
through the CCD Bus. The CCD Bus is a communi-
cations port. Various modules use the CCD Bus to
exchange information.
The Check Engine lamp comes on each time the
ignition key is turned ON and stays on for 3 seconds
as a bulb test.
The Malfunction Indicator Lamp (MIL) stays on
continuously, when the PCM has entered a Limp-In
mode or identified a failed emission component. Dur-
ing Limp-in Mode, the PCM attempts to keep the
system operational. The MIL signals the need for
immediate service. In limp-in mode, the PCM com-
pensates for the failure of certain components that
send incorrect signals. The PCM substitutes for the
incorrect signals with inputs from other sensors.
If the PCM detects active engine misfire severe
enough to cause catalyst damage, it flashes the MIL.
At the same time the PCM also sets a Diagnostic
Trouble Code (DTC).
For signals that can trigger the MIL (Check
Engine Lamp) refer to Group 25, On-Board
Dianostics.
SOLID STATE FAN RELAYÐPCM OUTPUT
The radiator fan runs at a variable speed depend-
ing on coolant temperature and A/C system pressure.
The radiator fan circuit contains a Solid State Fan
Relay (SSFR). Refer to the Group 8W for a circuit
schematic.
A 5 volt signal is supplied to the SSFR. The PCM
provides a pulsed ground for the SSFR. Depending
upon the amount of pulse on time, the SSFR puts out
a proportional voltage to the fan motor at the lower
speed. For instance, if the on time is 30 percent, then
the voltage to the fan motor will be 3.6 volts.
When engine coolant reaches approximately 102ÉC
(215ÉF) the PCM grounds the SSFR relay. If engine
coolant reaches 207ÉC (225ÉF) the PCM grounds the
high speed ground relay and high speed fan relay. If
the fan operates at high speed, the PCM de-energizes
the high speed relay and high speed ground relay
when coolant temperature drops to approximately
101ÉC (214ÉF). When coolant temperature drops to
101ÉC (214ÉF) the fan operates at low speed. The
PCM de-energizes the low speed relay when coolant
temperature drops to approximately 93ÉC (199ÉF).
Also, when the air conditioning pressure switch
closes, the fan operates at high speed. The air condi-
tioning switch closes at 285 psi610 psi. When air
conditioning pressure drops approximately 40 psi, the
pressure switch opens and the fan operates at low
speed.
The SSFR relay is located on the left front inner
frame just behind the radiator (Fig. 42).
SPEED CONTROL SOLENOIDSÐPCM OUTPUT
The speed control vacuum and vent solenoids are
operated by the PCM. When the PCM supplies a
ground to the vacuum and vent solenoids, the speed
control system opens the throttle plate. When the
PCM removes the ground from the vacuum and vent
solenoids, the throttle blade closes. The PCM bal-
Fig. 41 Ignition Coil Ð3.3/3.8L
Fig. 42 Fan Control Module
14 - 46 FUEL SYSTEMNS
DESCRIPTION AND OPERATION (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

DESCRIPTION AND OPERATION
SYSTEM DIAGNOSISÐ2.0L ENGINE
Refer to System diagnosis 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.
POWERTRAIN CONTROL MODULEÐ2.0L ENGINE
Refer to the Powertrain 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.
AIR CONDITIONING PRESSURE TRANSDUCERÐ
PCM INPUTÐ2.0L ENGINE
Refer to the Air Conditioning Pressure 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.
AIR CONDITIONING SWITCH SENSEÐPCM
INPUTÐ2.0L ENGINE
Refer to the Air Conditioning Switch Sense 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.
AUTOMATIC SHUTDOWN (ASD) SENSEÐPCM
INPUTÐ2.0L ENGINE
Refer to the Automatic Shutdown (ASD) Sense for
2.4/3.0/3.3/3.8L engines under Description and Oper-
ation in the Fuel Injection System section of group 14
for more information.
BATTERY VOLTAGEÐPCM INPUTÐ2.0L ENGINE
Refer to the Battery Voltage 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.
CAMSHAFT POSITION SENSORÐPCM INPUTÐ
2.0L ENGINE
Refer to the Camshaft Position Sensor for 2.4L
engine under Description and Operation in the Fuel
Injection System section of group 14 for more infor-
mation.
CRANKSHAFT POSITION SENSORÐPCM
INPUTÐ2.0L ENGINE
Refer to the Crankshaft Position Sensor for 2.4L
engine under Description and Operation in the Fuel
Injection System section of group 14 for more infor-
mation.
ENGINE COOLANT TEMPERATURE SENSORÐPCM
INPUTÐ2.0L ENGINE
The coolant temperature sensor threads into the
rear of the cylinder head, next to the camshaft posi-
tion sensor (Fig. 3). New sensors have sealant
applied to the threads.
Refer to the Engine Coolant Temperature Sensor
for the 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.
HEATED OXYGEN SENSORÐPCM INPUTÐ2.0L
ENGINE
Refer to the Heated Oxygen 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
information.
Fig. 1 Camshaft Position SensorÐ2.0L Engine
Fig. 2 Crankshaft Posistion SensorÐ2.0L engine
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 33

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)

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

illuminated constantly, it usually indicates a problem
has been detected somewhere within the fuel system.
The DRBIII scan tool is the best method for commu-
nicating with the PCM to diagnose faults within the
system.
DESCRIPTION AND OPERATION
POWERTRAIN CONTROL MODULE (PCM)
The Powertrain Control Module (PCM) is mounted
in the center consule to a bracket located in front of
the Air Bag Module (Fig. 1).
The PCM is a pre±programmed, dual micro±proces-
sor digital computer. It will either directly operate or
partially regulate the:
²Speed Control
²Speed Control LED lamp
²Fuel Timing Solenoid
²Glow Plug Relay
²Glow Plugs
²EGR Solenoid
²Glow Plug Lamp
²Diesel PCM Relay
²Air Conditioning Operation
²Tachometer
²Exhaust Gas Recirculation (EGR) Solenoid
The PCM can adapt its programming to meet
changing operating conditions.
The PCM receives input signals from various
switches and sensors. Based on these inputs, the
PCM regulates various engine and vehicle operationsthrough different system components. These compo-
nents are referred to asPCM Outputs.The sensors
and switches that provide inputs to the PCM are con-
sideredPCM Inputs.
PCM Inputs are:
²Air Conditioning Selection
²Theft Alarm
²Clutch Switch
²Diesel PCM Relay
²ISO-Protocol
²Control Sleeve
²Fuel Temperature
²Boost Pressure Sensor
²Accelerator Pedal Sensor
²EGR
²A/C Pressure
²Engine Coolant Temperature Sensor
²Low Idle Position Switch
²5 Volt Supply
²Vehicle Speed Sensor
²Sensor Return
²Glow Plug
²Engine Speed Sensor (rpm)
²Fuel Injector #1 Sensor
²Starter Signal
²Brake Switch
²Speed Control Switch Position
²Power Ground
²Signal Ground
²Ignition (key) Switch Sense
²Battery Voltage
²SCI Receive (DRB scan tool connection)
PCM Outputs:
After inputs are received by the PCM, certain sen-
sors, switches and components are controlled or reg-
ulated by the PCM. These are consideredPCM
Outputs.These outputs are for:
²A/C Clutch Relay (for A/C clutch operation)
²Speed Control LED
²Data Link Connectors (for DRB scan tool)
²Diesel PCM Relay
²Diesel PCM Sense
²Accelarator Pedal
²5 Volts Supply
²Glow Plug Relay
²Fan Relay
²Fuel Quantity
²Fuel Timing Solenoid
²Fuel Shut-Off Solenoid
²Engine Speed Sensor
²Glow Plug Lamp (malfunction indicator lamp)
²Exhaust Gas Recirculation (EGR) Solenoid
²Glow Plug Relay
²Tachometer
²SCI transmit (DRB scan tool connection)
Fig. 1 PCM Location
14 - 44 FUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINENS/GS
GENERAL INFORMATION (Continued)