2001 DODGE RAM fuel

(5) Disconnect the instrument panel wire harness
connectors and the antenna coaxial cable connector
from the receptacles on the rear of the radio receiver.
(6) If so equipped, remove the screw that secures
the ground wire to the back of the radio receiver
chassis.
(7) Remove the radio receiver from the instrument
panel.
INSTALLATION
(1) Position the radio receiver to the instrument
panel.
(2) If so equipped, install and tighten the screw
that secures the ground wire to the back of the radio
receiver chassis. Tighten the screw to 7 N´m (65 in.
lbs.).
(3) Reconnect the instrument panel wire harness
connectors and the antenna coaxial cable connector
to the receptacles on the rear of the radio receiver.
(4) Position the radio receiver into the mounting
hole in the instrument panel.
(5) Install and tighten the two screws that secure
the radio receiver to the instrument panel. Tighten
the screws to 5 N´m (45 in. lbs.).
(6) Install the cluster bezel onto the instrument
panel.
(7) Reconnect the battery negative cable.
RADIO NOISE SUPPRESSION
COMPONENTS
DESCRIPTION
Radio Frequency Interference (RFI) and Electro-
Magnetic Interference (EMI) noise suppression is
accomplished primarily through circuitry internal to
the radio receivers. These internal suppression
devices are only serviced as part of the radio receiver.
External suppression devices that are used on this
vehicle to control RFI or EMI noise include the fol-
lowing:
²Radio antenna base ground
²Radio receiver chassis ground wire or strap
²Engine-to-body ground straps
²Cab-to-bed ground strap
²Heater core ground strap
²Resistor-type spark plugs
²Radio suppression-type secondary ignition wir-
ing.
For more information on the spark plugs and sec-
ondary ignition components, refer to Electrical, Igni-
tion Control.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - RADIO NOISE
SUPPRESSION COMPONENTS
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
For complete circuit diagrams, refer to the appro-
priate wiring information. The wiring information
includes wiring diagrams, proper wire and connector
repair procedures, details of wire harness routing
and retention, connector pin-out information and
location views for the various wire harness connec-
tors, splices and grounds. Inspect the ground paths
and connections at the following locations:
²Blower motor
²Cab-to-bed ground strap
²Electric fuel pump
²Engine-to-body ground straps
²Generator
²Ignition module
²Heater core ground strap
²Radio antenna base ground
²Radio receiver chassis ground wire or strap
Fig. 9 Radio Receiver Connections - Typical
1 - ANTENNA CABLE
2 - RADIO
3 - INSTRUMENT PANEL WIRING
4 - GROUND WIRE
8A - 12 AUDIOBR/BE
RADIO (Continued)

²Head/Park Lights-On Warning- The CTM
chime tone generator will generate repetitive chime
tones at a fast rate to announce that hard wired
inputs from the driver door ajar switch, headlamp
switch, and ignition switch indicate that the exterior
lamps are turned On with the driver side front door
opened and the ignition switch in the Off position.
The chimes will continue to sound until the exterior
lamps are turned Off, the driver side front door is
closed, or the ignition switch is turned to the On
position, whichever occurs first.
²Key-In-Ignition Warning- The BCM chime
tone generator will generate repetitive chime tones at
a fast rate to announce that hard wired inputs from
the driver door ajar switch, headlamp switch, and
ignition switch indicate that the key is in the ignition
lock cylinder with the driver side front door opened
and the ignition switch in the Off position. The
chimes will continue to sound until the key is
removed from the ignition lock cylinder, the driver
side front door is closed, or the ignition switch is
turned to the On position, whichever occurs first.
²Warning Chime Support- The CTM chime
tone generator will generate repetitive chime tones at
a slow rate to announce that a hard wired chime
request input has been received from the EMIC.
These chime tones provide an audible alert to the
vehicle operator that supplements certain visual indi-
cations displayed by the EMIC. Supplemented indica-
tions include the following:
²The ªAirbagº indicator is illuminated. The
chimes will continue to sound for a duration of about
four seconds each time the indicator is illuminated or
until the ignition switch is turned to the Off position,
whichever occurs first.
²The ªCheck Gagesº indicator is illuminated. The
chimes will continue to sound for a duration of about
two seconds each time the indicator is illuminated or
until the ignition switch is turned to the Off position,
whichever occurs first.
²The ªLow Fuelº indicator is illuminated. The
chimes will continue to sound for a duration of about
two seconds each time the indicator is illuminated or
until the ignition switch is turned to the Off position,
whichever occurs first.
²The ªLow Washº indicator is illuminated. The
chimes will continue to sound for a duration of about
two seconds each time the indicator is illuminated or
until the ignition switch is turned to the Off position,
whichever occurs first.
²The ªTrans Tempº indicator is illuminated (auto-
matic transmission only). The chimes will continue to
sound for a duration of about two seconds each time
the indicator is illuminated or until the ignition
switch is turned to the Off position, whichever occurs
first.²The vehicle is over a programmed speed value
(Middle East Gulf Coast Country (GCC) only). The
CTM chime tone generator will generate repetitive
chime tones at a slow rate to announce that the vehi-
cle speed exceeds a programmed value. The chimes
will continue to sound until the vehicle speed is
below the programmed value.
²The ªWater-In-Fuelº indicator is illuminated
(diesel engine only). The chimes will continue to
sound for a duration of about two seconds each time
the indicator is illuminated or until the ignition
switch is turned to the Off position, whichever occurs
first.
The CTM provides chime service for all available
features in the chime warning system. The CTM
relies upon hard wired inputs from the driver door
ajar switch, the EMIC, the headlamp switch, and the
key-in ignition switch (ignition switch) to provide
chime service for all of the chime warning system
features. Upon receiving the proper inputs, the CTM
activates the integral chime tone generator to pro-
vide the audible chime tone to the vehicle operator.
The chime tone generator in the CTM is capable of
producing repeated chime tones at two different
rates, slow or fast. The slow chime rate is about fifty
chime tones per minute, while the fast chime rate is
about 180 chime tones per minute. The internal pro-
gramming of the CTM and the EMIC determines the
priority of each chime tone request input that is
received, as well as the rate and duration of each
chime tone that is to be generated.
The hard wired chime warning system inputs to
the CTM and the EMIC, as well as other hard wired
circuits for this system may be diagnosed and tested
using conventional diagnostic tools and procedures.
See the owner's manual in the vehicle glove box for
more information on the features provided by the
chime warning system.
DIAGNOSIS AND TESTING - CHIME WARNING
SYSTEM
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices and grounds. The hard wired
chime warning system inputs to the Central Timer
Module (CTM) and the Electro-Mechanical Instru-
ment Cluster (EMIC), as well as other hard wired
circuits for this system may be diagnosed and tested
using conventional diagnostic tools and procedures.
8B - 2 CHIME/BUZZERBR/BE
CHIME WARNING SYSTEM (Continued)

ENGINE CONTROL MODULE
DESCRIPTION - ECM
The ECM is bolted to the left side of the engine
behind the fuel filter (Fig. 14). It is a separate com-
ponent and can be serviced. The FPCM is internal to
the fuel injection pump (Fig. 15) and cannot be ser-
viced.
OPERATION - ECM
The main functions of the Engine Control Module
(ECM) and Fuel Injection Pump Control Module
(FPCM) are to electrically control the fuel system.
The Powertrain Control Module (PCM)does not
controlthe fuel system.
The ECM can adapt its programming to meet
changing operating conditions.If the ECM has
been replaced, flashed or re-calibrated, the
ECM must learn the Accelerator Pedal Position
Sensor (APPS) idle voltage. Failure to learn
this voltage may result in unnecessary diagnos-
tic trouble codes. Refer to ECM Removal/Instal-
lation for learning procedures.
The ECM receives input signals from various
switches and sensors. Based on these inputs, the
ECM regulates various engine and vehicle operations
through different system components. These compo-
nents are referred to asECM Outputs.The sensors
and switches that provide inputs to the ECM are
consideredECM Inputs.NOTE: ECM Inputs:
²Accelerator Pedal Position Sensor (APPS) Volts
²APPS Idle Validation Switches #1 and #2
²Battery voltage
²Camshaft Position Sensor (CMP)
²CCD bus (+) circuits
²CCD bus (-) circuits
²Crankshaft Position Sensor (CKP)
²Data link connection for DRB scan tool
²(FPCM) Fuel Injection Pump Control Module
²Engine Coolant Temperature (ECT) sensor
²Ground circuits
²Intake manifold Air Temperature (IAT) sensor
²Manifold Air Pressure Sensor (Boost Pressure
Sensor)
²Oil pressure sensor
²PCM
²Power Take Off (PTO)
²Power ground
²Sensor return
²Signal ground
²Water-In-Fuel (WIF) sensor
Fig. 14 Engine Control Module (ECM) Location
1 - ENGINE CONTROL MODULE (ECM)
2 - HEX HEADED BOLT
3 - 50-WAY CONNECTOR
4 - FUEL TRANSFER PUMP
5 - MOUNTING BOLTS (3)
Fig. 15 Fuel Injection Pump Control Module (FPCM)
Location
1 - FPCM ELECTRICAL CONNECTOR
2 - HIGH-PRESSURE FUEL LINES
3 - FITTINGS
4 - FUEL INJECTION PUMP
5 - FPCM
BR/BEELECTRONIC CONTROL MODULES 8E - 13

NOTE: ECM Outputs:
After inputs are received by the ECM, certain sen-
sors, switches and components are controlled or reg-
ulated by the ECM. These are consideredECM
Outputs.These outputs are for:
²CCD bus (+) circuits
²CCD bus (-) circuits
²CKP and APPS outputs to the PCM
²Data link connection for DRB scan tool
²Five volt sensor supply
²Fuel injection pump
²Fuel injection pump relay
²(FPCM) Fuel Pump Control Module
²Fuel transfer (lift) pump
²Intake manifold air heater relays #1 and #2 con-
trol circuits
²Malfunction indicator lamp (Check engine lamp)
²Oil pressure gauge/warning lamp
²PCM
²Wait-to-start warning lamp
²Water-In-Fuel (WIF) warning lamp
REMOVAL
The ECM is bolted to the engine block behind the
fuel filter (Fig. 16).
(1) Record any Diagnostic Trouble Codes (DTC's)
found in the PCM or ECM.To avoid possible voltage spike damage to either
the Powertrain Control Module (PCM) or ECM, igni-
tion key must be off, and negative battery cables
must be disconnected before unplugging ECM con-
nectors.
(2) Disconnect both negative battery cables at both
batteries.
(3) Remove 50±way electrical connector bolt at
ECM (Fig. 16). Note: Connector bolt is female 4mm
hex head. To remove bolt, use a ball-hex bit or ball-
hex screwdriver such as Snap-Ont4mm SDABM4
(5/32º may also be used). As bolt is being removed,
very carefully remove connector from ECM.
(4) Remove three ECM mounting bolts and remove
ECM from vehicle.
INSTALLATION
Do not apply paint to back of ECM. Poor ground
will result.
(1) Clean ECM mounting points at engine block.
(2) Position ECM to engine block and install 3
mounting bolts. Tighten bolts to 24 N´m (18 ft. lbs.).
(3) Check pin connectors in ECM and 50±way con-
nector for corrosion or damage. Repair as necessary.
(4) Clean pins in 50±way electrical connector with
a quick-dry electrical contact cleaner.
(5) Very carefully install 50±way connector to
ECM. Tighten connector hex bolt.
(6) Install battery cables.
(7)Turn key to ON position. Without starting
engine, slowly press throttle pedal to floor and
then slowly release. This step must be done
(one time) to ensure accelerator pedal position
sensor calibration has been learned by ECM. If
not done, possible DTC's may be set.
(8) Use DRB scan tool to erase any stored compan-
ion DTC's from PCM.
POWERTRAIN CONTROL
MODULE
DESCRIPTION - PCM
The Powertrain Control Module (PCM) is located
in the engine compartment (Fig. 17). The PCM is
referred to as JTEC.
DESCRIPTION - MODES OF OPERATION
As input signals to the Powertrain Control Module
(PCM) change, the PCM adjusts its response to the
output devices. For example, the PCM must calculate
different injector pulse width and ignition timing for
idle than it does for wide open throttle (WOT).
The PCM will operate in two different modes:
Open Loop and Closed Loop.
Fig. 16 Engine Control Module (ECM) Location and
Mounting
1 - ENGINE CONTROL MODULE (ECM)
2 - HEX HEADED BOLT
3 - 50-WAY CONNECTOR
4 - FUEL TRANSFER PUMP
5 - MOUNTING BOLTS (3)
8E - 14 ELECTRONIC CONTROL MODULESBR/BE
ENGINE CONTROL MODULE (Continued)

During Open Loop modes, the PCM receives input
signals and responds only according to preset PCM
programming. Input from the oxygen (O2S) sensors
is not monitored during Open Loop modes.
During Closed Loop modes, the PCM will monitor
the oxygen (O2S) sensors input. This input indicates
to the PCM whether or not the calculated injector
pulse width results in the ideal air-fuel ratio. This
ratio is 14.7 parts air-to-1 part fuel. By monitoring
the exhaust oxygen content through the O2S sensor,
the PCM can fine tune the injector pulse width. This
is done to achieve optimum fuel economy combined
with low emission engine performance.
The fuel injection system has the following modes
of operation:
²Ignition switch ON
²Engine start-up (crank)
²Engine warm-up
²Idle
²Cruise
²Acceleration
²Deceleration
²Wide open throttle (WOT)
²Ignition switch OFF
The ignition switch On, engine start-up (crank),
engine warm-up, acceleration, deceleration and wide
open throttle modes are Open Loop modes. The idle
and cruise modes, (with the engine at operating tem-
perature) are Closed Loop modes.
IGNITION SWITCH (KEY-ON) MODE
This is an Open Loop mode. When the fuel system
is activated by the ignition switch, the following
actions occur:²The PCM pre-positions the idle air control (IAC)
motor.
²The PCM determines atmospheric air pressure
from the MAP sensor input to determine basic fuel
strategy.
²The PCM monitors the engine coolant tempera-
ture sensor input. The PCM modifies fuel strategy
based on this input.
²Intake manifold air temperature sensor input is
monitored.
²Throttle position sensor (TPS) is monitored.
²The auto shutdown (ASD) relay is energized by
the PCM for approximately three seconds.
²The fuel pump is energized through the fuel
pump relay by the PCM. The fuel pump will operate
for approximately three seconds unless the engine is
operating or the starter motor is engaged.
²The O2S sensor heater element is energized via
the ASD relay. The O2S sensor input is not used by
the PCM to calibrate air-fuel ratio during this mode
of operation.
ENGINE START-UP MODE
This is an Open Loop mode. The following actions
occur when the starter motor is engaged.
The PCM receives inputs from:
²Battery voltage
²Engine coolant temperature sensor
²Crankshaft position sensor
²Intake manifold air temperature sensor
²Manifold absolute pressure (MAP) sensor
²Throttle position sensor (TPS)
²Starter motor relay
²Camshaft position sensor signal
The PCM monitors the crankshaft position sensor.
If the PCM does not receive a crankshaft position
sensor signal within 3 seconds of cranking the
engine, it will shut down the fuel injection system.
The fuel pump is activated by the PCM through
the fuel pump relay.
Voltage is applied to the fuel injectors with the
ASD relay via the PCM. The PCM will then control
the injection sequence and injector pulse width by
turning the ground circuit to each individual injector
on and off.
The PCM determines the proper ignition timing
according to input received from the crankshaft posi-
tion sensor.
ENGINE WARM-UP MODE
This is an Open Loop mode. During engine warm-
up, the PCM receives inputs from:
²Battery voltage
²Crankshaft position sensor
²Engine coolant temperature sensor
²Intake manifold air temperature sensor
Fig. 17 PCM Location
1 - PCM MOUNTING BOLTS (3)
2 - POWERTRAIN CONTROL MODULE (PCM)
3 - (3) 32±WAY CONNECTORS
BR/BEELECTRONIC CONTROL MODULES 8E - 15
POWERTRAIN CONTROL MODULE (Continued)

²Manifold absolute pressure (MAP) sensor
²Throttle position sensor (TPS)
²Camshaft position sensor signal (in the distribu-
tor)
²Park/neutral switch (gear indicator signalÐauto.
trans. only)
²Air conditioning select signal (if equipped)
²Air conditioning request signal (if equipped)
Based on these inputs the following occurs:
²Voltage is applied to the fuel injectors with the
ASD relay via the PCM. The PCM will then control
the injection sequence and injector pulse width by
turning the ground circuit to each individual injector
on and off.
²The PCM adjusts engine idle speed through the
idle air control (IAC) motor and adjusts ignition tim-
ing.
²The PCM operates the A/C compressor clutch
through the clutch relay. This is done if A/C has been
selected by the vehicle operator and requested by the
A/C thermostat.
²When engine has reached operating tempera-
ture, the PCM will begin monitoring O2S sensor
input. The system will then leave the warm-up mode
and go into closed loop operation.
IDLE MODE
When the engine is at operating temperature, this
is a Closed Loop mode. At idle speed, the PCM
receives inputs from:
²Air conditioning select signal (if equipped)
²Air conditioning request signal (if equipped)
²Battery voltage
²Crankshaft position sensor
²Engine coolant temperature sensor
²Intake manifold air temperature sensor
²Manifold absolute pressure (MAP) sensor
²Throttle position sensor (TPS)
²Camshaft position sensor signal (in the distribu-
tor)
²Battery voltage
²Park/neutral switch (gear indicator signalÐauto.
trans. only)
²Oxygen sensors
Based on these inputs, the following occurs:
²Voltage is applied to the fuel injectors with the
ASD relay via the PCM. The PCM will then control
injection sequence and injector pulse width by turn-
ing the ground circuit to each individual injector on
and off.
²The PCM monitors the O2S sensor input and
adjusts air-fuel ratio by varying injector pulse width.
It also adjusts engine idle speed through the idle air
control (IAC) motor.
²The PCM adjusts ignition timing by increasing
and decreasing spark advance.²The PCM operates the A/C compressor clutch
through the clutch relay. This happens if A/C has
been selected by the vehicle operator and requested
by the A/C thermostat.
CRUISE MODE
When the engine is at operating temperature, this
is a Closed Loop mode. At cruising speed, the PCM
receives inputs from:
²Air conditioning select signal (if equipped)
²Air conditioning request signal (if equipped)
²Battery voltage
²Engine coolant temperature sensor
²Crankshaft position sensor
²Intake manifold air temperature sensor
²Manifold absolute pressure (MAP) sensor
²Throttle position sensor (TPS)
²Camshaft position sensor signal (in the distribu-
tor)
²Park/neutral switch (gear indicator signalÐauto.
trans. only)
²Oxygen (O2S) sensors
Based on these inputs, the following occurs:
²Voltage is applied to the fuel injectors with the
ASD relay via the PCM. The PCM will then adjust
the injector pulse width by turning the ground circuit
to each individual injector on and off.
²The PCM monitors the O2S sensor input and
adjusts air-fuel ratio. It also adjusts engine idle
speed through the idle air control (IAC) motor.
²The PCM adjusts ignition timing by turning the
ground path to the coil on and off.
²The PCM operates the A/C compressor clutch
through the clutch relay. This happens if A/C has
been selected by the vehicle operator and requested
by the A/C thermostat.
ACCELERATION MODE
This is an Open Loop mode. The PCM recognizes
an abrupt increase in throttle position or MAP pres-
sure as a demand for increased engine output and
vehicle acceleration. The PCM increases injector
pulse width in response to increased throttle opening.
DECELERATION MODE
When the engine is at operating temperature, this
is an Open Loop mode. During hard deceleration, the
PCM receives the following inputs.
²Air conditioning select signal (if equipped)
²Air conditioning request signal (if equipped)
²Battery voltage
²Engine coolant temperature sensor
²Crankshaft position sensor
²Intake manifold air temperature sensor
²Manifold absolute pressure (MAP) sensor
²Throttle position sensor (TPS)
8E - 16 ELECTRONIC CONTROL MODULESBR/BE
POWERTRAIN CONTROL MODULE (Continued)

²Camshaft position sensor signal (in the distribu-
tor)
²Park/neutral switch (gear indicator signalÐauto.
trans. only)
²Vehicle speed sensor
If the vehicle is under hard deceleration with the
proper rpm and closed throttle conditions, the PCM
will ignore the oxygen sensor input signal. The PCM
will enter a fuel cut-off strategy in which it will not
supply a ground to the injectors. If a hard decelera-
tion does not exist, the PCM will determine the
proper injector pulse width and continue injection.
Based on the above inputs, the PCM will adjust
engine idle speed through the idle air control (IAC)
motor.
The PCM adjusts ignition timing by turning the
ground path to the coil on and off.
WIDE OPEN THROTTLE MODE
This is an Open Loop mode. During wide open
throttle operation, the PCM receives the following
inputs.
²Battery voltage
²Crankshaft position sensor
²Engine coolant temperature sensor
²Intake manifold air temperature sensor
²Manifold absolute pressure (MAP) sensor
²Throttle position sensor (TPS)
²Camshaft position sensor signal (in the distribu-
tor)
During wide open throttle conditions, the following
occurs:
²Voltage is applied to the fuel injectors with the
ASD relay via the PCM. The PCM will then control
the injection sequence and injector pulse width by
turning the ground circuit to each individual injector
on and off. The PCM ignores the oxygen sensor input
signal and provides a predetermined amount of addi-
tional fuel. This is done by adjusting injector pulse
width.
²The PCM adjusts ignition timing by turning the
ground path to the coil on and off.
IGNITION SWITCH OFF MODE
When ignition switch is turned to OFF position,
the PCM stops operating the injectors, ignition coil,
ASD relay and fuel pump relay.
DESCRIPTION - 5 VOLT SUPPLIES
Two different Powertrain Control Module (PCM)
five volt supply circuits are used; primary and sec-
ondary.
DESCRIPTION - IGNITION CIRCUIT SENSE
This circuit ties the ignition switch to the Power-
train Control Module (PCM).
DESCRIPTION - POWER GROUNDS
The Powertrain Control Module (PCM) has 2 main
grounds. Both of these grounds are referred to as
power grounds. All of the high-current, noisy, electri-
cal devices are connected to these grounds as well as
all of the sensor returns. The sensor return comes
into the sensor return circuit, passes through noise
suppression, and is then connected to the power
ground.
The power ground is used to control ground cir-
cuits for the following PCM loads:
²Generator field winding
²Fuel injectors
²Ignition coil(s)
²Certain relays/solenoids
²Certain sensors
DESCRIPTION - SENSOR RETURN
The Sensor Return circuits are internal to the Pow-
ertrain Control Module (PCM).
Sensor Return provides a low±noise ground refer-
ence for all engine control system sensors. Refer to
Power Grounds for more information.
DESCRIPTION - SIGNAL GROUND
Signal ground provides a low noise ground to the
data link connector.
OPERATION - PCM - GAS ENGINES
The PCM operates the fuel system. The PCM is a
pre-programmed, triple microprocessor digital com-
puter. It regulates ignition timing, air-fuel ratio,
emission control devices, charging system, certain
transmission features, speed control, air conditioning
compressor clutch engagement and idle speed. 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 operations
through different system components. These compo-
nents are referred to as Powertrain Control Module
(PCM) Outputs. The sensors and switches that pro-
vide inputs to the PCM are considered Powertrain
Control Module (PCM) Inputs.
The PCM adjusts ignition timing based upon
inputs it receives from sensors that react to: engine
rpm, manifold absolute pressure, engine coolant tem-
perature, throttle position, transmission gear selec-
tion (automatic transmission), vehicle speed and the
brake switch.
The PCM adjusts idle speed based on inputs it
receives from sensors that react to: throttle position,
vehicle speed, transmission gear selection, engine
coolant temperature and from inputs it receives from
the air conditioning clutch switch and brake switch.
BR/BEELECTRONIC CONTROL MODULES 8E - 17
POWERTRAIN CONTROL MODULE (Continued)

Based on inputs that it receives, the PCM adjusts
ignition coil dwell. The PCM also adjusts the gener-
ator charge rate through control of the generator
field and provides speed control operation.
NOTE: PCM Inputs:
²A/C request (if equipped with factory A/C)
²A/C select (if equipped with factory A/C)
²Auto shutdown (ASD) sense
²Battery temperature
²Battery voltage
²Brake switch
²CCD bus (+) circuits
²CCD bus (-) circuits
²Camshaft position sensor signal
²Crankshaft position sensor
²Data link connection for DRB scan tool
²Engine coolant temperature sensor
²Fuel level
²Generator (battery voltage) output
²Ignition circuit sense (ignition switch in on/off/
crank/run position)
²Intake manifold air temperature sensor
²Leak detection pump (switch) sense (if equipped)
²Manifold absolute pressure (MAP) sensor
²Oil pressure
²Output shaft speed sensor
²Overdrive/override switch
²Oxygen sensors
²Park/neutral switch (auto. trans. only)
²Power ground
²Sensor return
²Signal ground
²Speed control multiplexed single wire input
²Throttle position sensor
²Transmission governor pressure sensor
²Transmission temperature sensor
²Vehicle speed inputs from ABS or RWAL system
NOTE: PCM Outputs:
²A/C clutch relay
²Auto shutdown (ASD) relay
²CCD bus (+/-) circuits for: speedometer, voltme-
ter, fuel gauge, oil pressure gauge/lamp, engine temp.
gauge and speed control warn. lamp
²Data link connection for DRB scan tool
²EGR valve control solenoid (if equipped)
²EVAP canister purge solenoid
²Five volt sensor supply (primary)
²Five volt sensor supply (secondary)
²Fuel injectors
²Fuel pump relay
²Generator field driver (-)
²Generator field driver (+)
²Generator lamp (if equipped)²Idle air control (IAC) motor
²Ignition coil
²Leak detection pump (if equipped)
²Malfunction indicator lamp (Check engine lamp).
Driven through CCD circuits.
²Overdrive indicator lamp (if equipped)
²Service Reminder Indicator (SRI) Lamp (MAINT
REQ'D lamp). Driven through CCD circuits.
²Speed control vacuum solenoid
²Speed control vent solenoid
²Tachometer (if equipped). Driven through CCD
circuits.
²Transmission convertor clutch circuit
²Transmission 3±4 shift solenoid
²Transmission relay
²Transmission temperature lamp (if equipped)
²Transmission variable force solenoid
OPERATION - DIESEL
Two different control modules are used: The Pow-
ertrain Control Module (PCM), and the Engine Con-
trol Module (ECM). The ECMcontrolsthe fuel
system. The PCMdoes not controlthe fuel system.
The PCM's main function is to control: the vehicle
charging system, speed control system, transmission,
air conditioning system and certain bussed messages.
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 operations
through 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.
NOTE: PCM Inputs:
²A/C request (if equipped with factory A/C)
²A/C select (if equipped with factory A/C)
²Accelerator Pedal Position Sensor (APPS) output
from ECM
²Auto shutdown (ASD) relay sense
²Battery temperature sensor
²Battery voltage
²Brake switch
²CCD bus (+) circuits
²CCD bus (-) circuits
²Crankshaft Position Sensor (CKP) output from
ECM
²Data link connection for DRB scan tool
²Fuel level sensor
²Generator (battery voltage) output
²Ignition sense
²Output shaft speed sensor
²Overdrive/override switch
²Park/neutral switch (auto. trans. only)
8E - 18 ELECTRONIC CONTROL MODULESBR/BE
POWERTRAIN CONTROL MODULE (Continued)