ESP DODGE RAM 2003 Service User Guide

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(s) 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)
²Camshaft position sensor signal
²Park/neutral switch (gear indicator signalÐauto.
trans. only)
²Vehicle speed
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) sensor²Throttle position sensor (TPS)
²Camshaft position sensor signal
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(s) 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.
8E - 10 ELECTRONIC CONTROL MODULESDR
POWERTRAIN CONTROL MODULE (Continued)

(2) Tighten bolts. Refer to torque specifications.
(3) Check pin connectors in the PCM and the three
32±way connectors (four 38±way connectors if
equipped with NGC) for corrosion or damage. Also,
the pin heights in connectors should all be same.
Repair as necessary before installing connectors.
(4) Install three 32±way connectors (four 38±way
connectors if equipped with NGC).
(5) Install cover over electrical connectors. Cover
snaps onto PCM.
(6) Install negative battery cable.
(7) Use the DRB scan tool to reprogram new PCM
with vehicles original Vehicle Identification Number
(VIN) and original vehicle mileage.
SENTRY KEY IMMOBILIZER
MODULE
DESCRIPTION
The Sentry Key Immobilizer Module (SKIM) con-
tains a Radio Frequency (RF) transceiver and a cen-
tral processing unit, which includes the Sentry Key
Immobilizer System (SKIS) program logic. The SKIS
programming enables the SKIM to program and
retain in memory the codes of at least two, but no
more than eight electronically coded Sentry Key
transponders. The SKIS programming also enables
the SKIM to communicate over the Programmable
Communication Interface (PCI) bus network with the
Powertrain Control Module (PCM), and/or the
DRBIIItscan tool.
OPERATION
The SKIM transmits and receives RF signals
through a tuned antenna enclosed within a molded
plastic ring that is integral to the SKIM housing.
When the SKIM is properly installed on the steering
column, the antenna ring is oriented around the igni-
tion lock cylinder housing. This antenna ring must be
located within eight millimeters (0.31 inches) of the
Sentry Key in order to ensure proper RF communica-
tion between the SKIM and the Sentry Key tran-
sponder.
For added system security, each SKIM is pro-
grammed with a unique ªSecret Keyº code and a
security code. The SKIM keeps the ªSecret Keyº code
in memory. The SKIM also sends the ªSecret Keyº
code to each of the programmed Sentry Key tran-
sponders. The security code is used by the assembly
plant to access the SKIS for initialization, or by the
dealer technician to access the system for service.
The SKIM also stores in its memory the Vehicle
Identification Number (VIN), which it learns through
a PCI bus message from the PCM during initializa-
tion.The SKIM and the PCM both use software that
includes a rolling code algorithm strategy, which
helps to reduce the possibility of unauthorized SKIS
disarming. The rolling code algorithm ensures secu-
rity by preventing an override of the SKIS through
the unauthorized substitution of the SKIM or the
PCM. However, the use of this strategy also means
that replacement of either the SKIM or the PCM
units will require a system initialization procedure to
restore system operation.
When the ignition switch is turned to the ON or
START positions, the SKIM transmits an RF signal
to excite the Sentry Key transponder. The SKIM then
listens for a return RF signal from the transponder
of the Sentry Key that is inserted in the ignition lock
cylinder. If the SKIM receives an RF signal with
valid ªSecret Keyº and transponder identification
codes, the SKIM sends a ªvalid keyº message to the
PCM over the PCI bus. If the SKIM receives an
invalid RF signal or no response, it sends ªinvalid
keyº messages to the PCM. The PCM will enable or
disable engine operation based upon the status of the
SKIM messages.
The SKIM also sends messages to the Instrument
Cluster which controls the VTSS indicator LED. The
SKIM sends messages to the Instrument Cluster to
turn the LED on for about three seconds when the
ignition switch is turned to the ON position as a bulb
test. After completion of the bulb test, the SKIM
sends bus messages to keep the LED off for a dura-
tion of about one second. Then the SKIM sends mes-
sages to turn the LED on or off based upon the
results of the SKIS self-tests. If the VTSS indicator
LED comes on and stays on after the bulb test, it
indicates that the SKIM has detected a system mal-
function and/or that the SKIS has become inopera-
tive.
If the SKIM detects an invalid key when the igni-
tion switch is turned to the ON position, it sends
messages to flash the VTSS indicator LED. The
SKIM can also send messages to flash the LED as an
indication to the customer that the SKIS has been
placed in it's ªCustomer Learnº programming mode.
See Sentry Key Immobilizer System Transponder
Programming in this section for more information on
the ªCustomer Learnº programming mode.
For diagnosis or initialization of the SKIM and the
PCM, a DRBIIItscan tool and the proper Powertrain
Diagnostic Procedures manual are required. The
SKIM cannot be repaired and, if faulty or damaged,
the unit must be replaced.
DRELECTRONIC CONTROL MODULES 8E - 13
POWERTRAIN CONTROL MODULE (Continued)

ments for shifting are not met, illuminate the 4H
LED and flash the destination LED as an indication
to the driver that all of the driver controllable shift
conditions are not being met). If this requires
another range or mode shift, begin the range/mode
shift process.
²If the desired mode sensor code is not received
after the shift timer expires (i.e. a blocked or other
condition exists), refer to the section on Blocked Shift
Strategy.
BLOCKED SHIFT STRATEGY
When a shift is commanded, the shift motor will be
driven towards its destination position, except in the
case of shifting out of Neutral if 4L was selected (the
transfer case will shift to the 4H position first, before
proceeding to 4L). If the shift is blocked on the way
to the destination, the TCCM may attempt to drive
the motor back to the original position. This process
will be allowed to occur 5 times. If the transfer case
has reached a non-NEUTRAL 'D' channel during the
shift re-attempts, the LED for the achieved gear posi-
tion is illuminated and the shift attempts are
stopped. To re-attempt the desired shift, the selector
switch will need to be rotated to the current position
until the switch debounce timer expires then a shift
will need to be requested again.
At the end of the 5th blocked attempt, the shift
motor is driven towards the last known 'D' channel
position. If this motor drive allows the transfer case
to reach the 2WD/AWD 'D' channel, or the 2WD/AWD
between gear position on the 4H side of 2WD/AWD,
the shift is considered complete and the shift
attempts are ended.
If the mode sensor is in the NEUTRAL region at
the expiration of the shift timer, the TCCM will con-
tinue to make the shift attempts according to the
blocked shift strategy independent of whether or not
the driver controlled conditions are met.
For shifts from NEUTRAL, if all 5 attempts fail to
reach the desired position (which by default is 4H),
the motor will be driven to stall in the direction of
4H or 4L, depending on the achieved position. If the
transfer case has reached the 2WD/AWD or 4L
between gear position nearest the NEUTRAL posi-
tions and the shift conditions are no longer being
met, the transfer case will be driven toward the cor-
responding 'D' channel. Otherwise, the transfer case
will be driven in the direction opposite the last
attempt with the desired target being 4H or 4L.
If the transfer case reaches the 2WD/AWD 'D'
channel when being driven in the 4H direction, then
one final 1.0 second drive toward 4H is attempted. If
the transfer case then reaches any of the 4H posi-
tions, the shift is considered complete and the 4H
LED is illuminated. If the transfer case is still the2WD/AWD position, the shift is considered complete
and the 2WD/AWD LED is illuminated.
NOTE: If after the 5th blocked shift and reversal
attempt, if the transfer case position is in the NEU-
TRAL region, shift attempts will continue until a
non-NEUTRAL 'D' channel is reached.
SHIFT REVERSAL TARGETS
If the shift timer expires (1 second per 'D' channel)
and the transfer case has not reached the desired
position, all shifts will attempt to return to their
original position with the exceptions of:
²If the intended shift is going to the High rail
from Low and can't make it, but it can make the
2WD/AWD position, the motor stops at that position.
The TCCM will not attempt to cross back over NEU-
TRAL if it does not have to. This means that there
was a block on the first attempt to go to 4H and the
transfer case has made it through NEUTRAL to a
known good position, then the motor will go back
only to the 2WD/4WD position and execute the
remainder of the attempts from there.
²For shifts out of NEUTRAL, any time a shift is
commanded out of NEUTRAL, the system needs to
get out. The TCCM should never go to NEUTRAL
unless the driver is commanding it and all required
conditions are being met
ENCODER DRIFT CORRECTION
Whenever a shift is completed, the TCCM stores
the position in memory as the transfer case's
intended position. The TCCM continuously monitors
the mode sensor and if the mode sensor drifts toward
into a NEUTRAL region sensor position for 2.0 sec-
onds, the TCCM will perform a motor drive to correct
the drift. The transfer case will be driven toward the
intended position for 1.0 seconds 100 msec. The
TCCM will wait for 2.0 seconds  50 msec. and repeat
the attempt to shift to the desired position. This will
continue until the intended position is reached.
SHIFT MOTOR BRAKING
Two modes of shift motor braking are employed to
improve shift performance, static and dynamic. Static
shift motor braking is utilized under the following
conditions:
²Whenever the transfer case is in the 2WD/AWD
or 4L 'D' channel position.
²Whenever an invalid mode sensor code is
present.
Static motor braking is achieved by applying +12V
on both shift motor wires.
NOTE: Static Shift Motor Braking is independent of
ignition key position.
8E - 18 ELECTRONIC CONTROL MODULESDR
TRANSFER CASE CONTROL MODULE (Continued)

SHIFT ATTEMPT LIMIT
To protect the transfer case system, the TCCM will
impose a limit on the number of shifts that can occur
over a calibrated time period. The system will monitor
the number of 'D' channel segment transitions that
occur in any 30 second time period. If the number of
segment transitions is 30 or greater, the system will go
into a default mode. The default mode of operation for
shifting is that the number of allowed 'D' channel tran-
sitions permitted to occur will be 3 over each 15 second
 100 msec calibrated window of time. After 5 minutes
 100 msec, the motor can be assumed to have cooled
down and the system will revert to normal operation.
The following rules also apply to the shift limit:
²The attempt limit will not prevent shifts coming
out of NEUTRAL, they will be allowed regardless of
the counter/timer.
²Any shift that is in progress when the counter
reaches a maximum count in time will be allowed to
complete before the default mode is entered. D-chan-
nel transitions during this period will not be counted
towards the default mode limit.
²A block, regardless of the direction, whether
towards destination or back towards reversal target
(shift timer expiring), will count as a value of 2 tran-
sitions towards the 30 segment transitions to go into
default mode as defined above. Current attempt limit
values are 30 transitions in 30 seconds and default
mode values are 3 transitions every 15 seconds for 5
minutes.
TRANSMISSION CONTROL
MODULE
DESCRIPTION
The Transmission Control Module (TCM) (Fig. 10)
may be sub-module within the Powertrain Control
Module (PCM) or a standalone module, depending on
the vehicle engine. The PCM, and TCM when
equipped, is located at the right rear of the engine
compartment, near the right inner fender.
OPERATION
The Transmission Control Module (TCM) controls
all electronic operations of the transmission. The
TCM receives information regarding vehicle opera-
tion from both direct and indirect inputs, and selects
the operational mode of the transmission. Direct
inputs are hardwired to, and used specifically by the
TCM. Indirect inputs are shared with the TCM via
the vehicle communication bus.
Some examples ofdirect inputsto the TCM are:
²Battery (B+) voltage
²Ignition ªONº voltage
²Transmission Control Relay (Switched B+)²Throttle Position Sensor
²Crankshaft Position Sensor
²Transmission Range Sensor
²Pressure Switches
²Transmission Temperature Sensor
²Input Shaft Speed Sensor
²Output Shaft Speed Sensor
²Line Pressure Sensor
Some examples ofindirect inputsto the TCM are:
²Engine/Body Identification
²Manifold Pressure
²Target Idle
²Torque Reduction Confirmation
²Engine Coolant Temperature
²Ambient/Battery Temperature
²DRBIIItScan Tool Communication
Based on the information received from these var-
ious inputs, the TCM determines the appropriate
shift schedule and shift points, depending on the
present operating conditions and driver demand.
This is possible through the control of various direct
and indirect outputs.
Some examples of TCMdirect outputsare:
²Transmission Control Relay
²Solenoids
²Torque Reduction Request
Some examples of TCMindirect outputsare:
²Transmission Temperature (to PCM)
²PRNDL Position (to BCM)
In addition to monitoring inputs and controlling
outputs, the TCM has other important responsibili-
ties and functions:
²Storing and maintaining Clutch Volume Indexes
(CVI)
²
Storing and selecting appropriate Shift Schedules
²System self-diagnostics
²Diagnostic capabilities (with DRBIIItscan tool)
Fig. 10 PCM/TCM Location
1 - RIGHT FENDER
2 - TRANSMISSION CONTROL MODULE
3 - POWERTRAIN CONTROL MODULE
DRELECTRONIC CONTROL MODULES 8E - 19
TRANSFER CASE CONTROL MODULE (Continued)

SPECIAL TOOLS
BATTERY SYSTEM SPECIAL TOOLS
BATTERY
DESCRIPTION
A large capacity, low-maintenance storage battery
(Fig. 4) is standard factory-installed equipment on
this model. Models equipped with a diesel engine
must utilize two 12-volt batteries connected in paral-
lel. Male post type terminals made of a soft lead
material protrude from the top of the molded plastic
battery case to provide the means for connecting the
battery to the vehicle electrical system. The battery
positive terminal post is physically larger in diameter
than the negative terminal post to ensure proper bat-
tery connection. The lettersPOSandNEGare also
molded into the top of the battery case adjacent to
their respective positive and negative terminal posts
for identification confirmation. Refer to Battery
Cables for more information on the battery cables
that connect the battery to the vehicle electrical sys-
tem.
The battery is made up of six individual cells that
are connected in series. Each cell contains positively
charged plate groups that are connected with lead
straps to the positive terminal post, and negatively
charged plate groups that are connected with lead
straps to the negative terminal post. Each plate con-
sists of a stiff mesh framework or grid coated with
lead dioxide (positive plate) or sponge lead (negative
plate). Insulators or plate separators made of a non-
conductive material are inserted between the positive
and negative plates to prevent them from contacting
or shorting against one another. These dissimilar
metal plates are submerged in a sulfuric acid and
water solution called an electrolyte.
The factory-installed battery has a built-in test
indicator (hydrometer). The color visible in the sight
glass of the indicator will reveal the battery condi-
tion. Refer to Standard Procedures for the proper
built-in indicator test procedures.The factory-in-
stalled low-maintenance battery has non-re-
movable battery cell caps.Water cannot be added
to this battery. The battery is not sealed and has
vent holes in the cell caps. The chemical composition
of the metal coated plates within the low-mainte-
nance battery reduces battery gassing and water
loss, at normal charge and discharge rates. There-
fore, the battery should not require additional water
in normal service. Rapid loss of electrolyte can be
caused by an overcharging condition.
DIAGNOSIS AND TESTING - BATTERY
The battery must be completely charged and the
terminals should be properly cleaned and inspected
before diagnostic procedures are performed. Refer to
Battery System Cleaning for the proper cleaning pro-
cedures, and Battery System Inspection for the
proper battery inspection procedures. Refer to Stan-
dard Procedures for the proper battery charging pro-
cedures.
Micro 420 Battery Tester
Fig. 4 Low-Maintenance Battery - Typical
1 - POSITIVE POST
2 - VENT
3 - CELL CAP
4 - TEST INDICATOR (IF EQUIPPED)
5 - CELL CAP
6 - VENT
7 - NEGATIVE POST
8 - GREEN BALL
9 - ELECTROLYTE LEVEL
10 - PLATE GROUPS
11 - LOW-MAINTENANCE BATTERY
DRBATTERY SYSTEM 8F - 7
BATTERY SYSTEM (Continued)

OPERATION
The heated seat module receives fused battery cur-
rent through the Integrated Power Module only when
the engine is running. The heated seat switches
receive battery current through fuse #48 in the Inte-
grated Power Module only when the ignition switch
is in the On position. The heated seat module shares
a common ground circuit with each of the heated seat
elements. The heated seat system will only operate
when the surface temperature of the seat cushion is
below the designed temperature set points of the sys-
tem.
The heated seat system will also automatically
turn off whenever the ignition switch is turned to
any position except On, or if the engine quits run-
ning. If the ignition switch is turned to the Off posi-
tion or if the engine quits running while a heated
seat is ON, the heated seat will remain Off after the
engine is restarted until a heated seat switch is
depressed again. This helps prevent the vehicles bat-
tery from being drained by the heated seat system.The heated seat module monitors inputs from the
heated seat sensors and the heated seat switches. In
response to these inputs the heated seat module uses
its internal programming to control 12v to the heated
seat elements in both front seats and to control the
heated seat LED indicator lamps located in both of
the heated seat switches. The heated seat module is
also programmed to provide self-diagnostics, if a
problem with the heated seat system is detected. If
the module detects certain failures within the heated
seat system, it will provide a visual indication of the
failure by flashing the indicator lamps in the appro-
priate heated seat switch. The heated seat module
will automatically turn off the heated seat elements
if it detects a short or open in the heated seat ele-
ment circuit or a heated seat sensor value that is out
of range.
DIAGNOSIS AND TESTING - HEATED SEAT
SYSTEM
HEATED SEAT SYSTEM SELF-DIAGNOSIS
The heated seat system is capable of performing
some self-diagnostics. The following table depicts the
various monitored failures which will be reported to
the vehicle operator or technician by flashing the
individual heated seat switch Light Emitting Diode
(LED) indicator lamps. Refer to the HEATED SEAT
SYSTEM SELF-DIAGNOSIS table for failure identi-
fication. The drivers heated seat switch indicator
lamps will flash if a failure occurs in the driver
heated seat, and the passengers heated seat switch
indicator lamps will flash for a passenger heated seat
failure. If a monitored heated seat system failure
occurs, the switch indicator lamps will flash at a
pulse rate of about one-half second on, followed by
about one-half second off for a duration of about one
minute after the switch for the faulty heated seat is
depressed in either the Low or High direction. This
process will repeat every time the faulty heated seat
switch is actuated until the problem has been cor-
rected.
HEATED SEAT SYSTEM SELF-DIAGNOSIS
Monitored FailureSwitch High
Indicator LampSwitch Low
Indicator Lamp
Heated Seat
Element ShortedFlashing Flashing
Heated Seat
Element OpenFlashing Off
Heated Seat
Sensor Value Out
of RangeOff Flashing
Fig. 1 DR Heated Seat System Diagram
1 - WIRE HARNESS
2 - DRIVER HEATED SEAT SWITCH
3 - PASSENGER HEATED SEAT SWITCH
4 - PASSENGER HEATED SEAT CUSHION ELEMENT
5 - SEAT CUSHION/BACK ELEMENT ELECTRICAL CONNECTOR
LOCATION
6 - DRIVER HEATED SEAT BACK ELEMENT
7 - DRIVER HEATED SEAT CUSHION ELEMENT
8 - HEATED SEAT MODULE
8G - 4 HEATED SEAT SYSTEMDR
HEATED SEAT SYSTEM (Continued)

The Auto Shutdown (ASD) relay provides battery
voltage to each ignition coil.
The ignition system consists of:
²6 Spark Plugs
²6 Separate Ignition Coils
²2 Knock Sensors
²Powertrain Control Module (PCM)
²Also to be considered part of the ignition system
are certain inputs from the Crankshaft Position,
Camshaft Position, Throttle Position, 2 knock and
MAP Sensors
4.7L V-8 ENGINE
The 4.7L V-8 engine uses a separate ignition coil for
each cylinder. The one-piece coil bolts directly to the
cylinder head. Rubber boots seal the secondary termi-
nal ends of the coils to the top of all 8 spark plugs. A
separate electrical connector is used for each coil.
Because of coil design, spark plug cables (second-
ary cables) are not used. A distributor is not used
with the 4.7L engine.
Two knock sensors (one for each cylinder bank) are
used to help control spark knock.
The Auto Shutdown (ASD) relay provides battery
voltage to each ignition coil.
The ignition system consists of:
²8 Spark Plugs
²8 Separate Ignition Coils
²2 Knock Sensors
²Powertrain Control Module (PCM)
²Also to be considered part of the ignition system
are certain inputs from the Crankshaft Position,
Camshaft Position, Throttle Position, 2 knock and
MAP Sensors
5.7L V-8 ENGINE
For additional information, also refer to Igni-
tion Coil Description and Operation.
The 5.7L V-8 engine is equipped with 16 spark
plugs. Two plugs are used for each cylinder. The 5.7L
is also equipped with 8 separate and independent
ignition coils. The one-piece coil bolts directly to the
cylinder head cover and attaches the coils secondary
output terminal directly to a spark plug using a rub-
ber boot seal. Each coil is also equipped with a sec-
ond output terminal. This second terminal connects a
conventional spark plug cable directly to a spark
plug on the opposite cylinder bank. A separate pri-
mary electrical connector is used for each coil.
Eight conventional spark plug cables are used with
the 5.7L. These cables connect a coil on one cylinder
bank, directly to a spark plug on the opposite cylin-
der bank. The cables are placed and routed in a spe-
cial plastic loom to keep them separated. This loom is
clipped to the intake manifold. To prevent a miss-
match of cables, a corresponding spark plug / coil
number is displayed on each plug cable: 1/6, 2/3, 4/7and 5/8. These numbers can also be found on the top
of the intake manifold to the right of the throttle
body (Fig. 1).
Two knock sensors (one for each cylinder bank) are
used to help control spark knock.
The 5.7L engine will not use a conventional distrib-
utor.
The ignition system consists of:
²16 Spark Plugs (2 per cylinder)
²
8 Separate, Dual-Secondary Output, Ignition Coils
²2 Knock Sensors
²8 Secondary Ignition Cables
²Powertrain Control Module (PCM)
²Also to be considered part of the ignition system
are certain inputs from the Crankshaft Position,
Camshaft Position, Throttle Position, 2 knock and
MAP Sensors
5.9L V-8 ENGINE
The 5.9L V-8 ignition system will use a conven-
tional distributor and 1 remotely mounted coil. Con-
ventional spark plug cables are used with the 5.9L.
Knock sensors are not used with the 5.9L engine.
The ignition system consists of:
²8 Spark Plugs
²1 Ignition Coil
²Secondary Ignition Cables
²Distributor (contains rotor and camshaft position
sensor)
²Powertrain Control Module (PCM)
Fig. 1 FIRING ORDER / CABLE ROUTING - 5.7L V-8
ENGINE
1 - TOP OF INTAKE MANIFOLD
2 - CYLINDER FIRING ORDER (IGNITION COIL NUMBER)
3 - CORRESPONDING SPARK PLUG NUMBER
8I - 2 IGNITION CONTROLDR
IGNITION CONTROL (Continued)

ENGINE FIRING ORDER - 3.7L V-6
1-6-5-4-3-2
ENGINE FIRING ORDER ± 4.7L V-8
FIRING ORDER / CABLE ROUTING ± 5.7L V-8
ENGINE
Eight conventional spark plug cables are used with
the 5.7L. These cables connect a coil on one cylinder
bank, directly to a spark plug on the opposite cylin-
der bank. The cables are placed and routed in a spe-
cial plastic loom to keep them separated. This loom is
clipped to the intake manifold. To prevent a miss-
match of cables, a corresponding spark plug / coil
number is displayed on each plug cable: 1/6, 2/3, 4/7
and 5/8. These numbers can also be found on the top
of the intake manifold to the right of the throttle
body (Fig. 2).
ENGINE FIRING ORDER - 5.9L V-8
Fig. 2 FIRING ORDER / CABLE ROUTING - 5.7L V-8
ENGINE
1 - TOP OF INTAKE MANIFOLD
2 - CYLINDER FIRING ORDER (IGNITION COIL NUMBER)
3 - CORRESPONDING SPARK PLUG NUMBER
8I - 4 IGNITION CONTROLDR
IGNITION CONTROL (Continued)

(3) Check condition of relay terminals and PDC
connector terminals for damage or corrosion. Repair
if necessary before installing relay.
(4) Check for pin height (pin height should be the
same for all terminals within the PDC connector).
Repair if necessary before installing relay.
INSTALLATION
The ASD relay is located in the Power Distribution
Center (PDC) (Fig. 5). Refer to label on PDC cover
for relay location.
(1) Install relay to PDC.
(2) Install cover to PDC.
CAMSHAFT POSITION
SENSOR
DESCRIPTION
3.7L V-6
The Camshaft Position Sensor (CMP) on the 3.7L
6-cylinder engine is bolted to the right-front side of
the right cylinder head.
4.7L V-8
The Camshaft Position Sensor (CMP) on the 4.7L
V-8 engine is bolted to the right-front side of the
right cylinder head.
5.7L V-8
The Camshaft Position Sensor (CMP) on the 5.7L
V-8 engine is located below the generator on the tim-
ing chain / case cover on the right/front side of
engine.
5.9L Diesel
The Camshaft Position Sensor (CMP) on the 5.9L
diesel engine is located below the fuel injection
pump. It is bolted to the back of the timing gear
cover.
5.9L V-8 Gas
The Camshaft Position Sensor (CMP) on the 5.9L
V-8 engine is located inside the distributor.
8.0L V±10
The Camshaft Position Sensor (CMP) on the 8.0L
V-10 engine is located on the timing chain / case
cover on the left/front side of engine.
OPERATION
3.7L V-6
The Camshaft Position Sensor (CMP) sensor on the
3.7L V-6 engine contains a hall effect device referred
to as a sync signal generator. A rotating target wheel
(tonewheel) for the CMP is located at the front of the
camshaft for the right cylinder head (Fig. 6). This
sync signal generator detects notches located on a
tonewheel. As the tonewheel rotates, the notches
pass through the sync signal generator. The signal
from the CMP sensor is used in conjunction with the
Crankshaft Position Sensor (CKP) to differentiate
between fuel injection and spark events. It is also
used to synchronize the fuel injectors with their
respective cylinders.
When the leading edge of the tonewheel notch
enters the tip of the CMP, the interruption of mag-
netic field causes the voltage to switch high, result-
ing in a sync signal of approximately 5 volts.
When the trailing edge of the tonewheel notch
leaves then tip of the CMP, the change of the mag-
netic field causes the sync signal voltage to switch
low to 0 volts.
4.7L V-8
The CMP sensor on the 4.7L engine contains a hall
effect device called a sync signal generator to gener-
ate a fuel sync signal. This sync signal generator
detects notches located on a tonewheel. The tone-
wheel is located at the front of the camshaft for the
right cylinder head (Fig. 7). As the tonewheel rotates,
the notches pass through the sync signal generator.
The pattern of the notches (viewed counter-clockwise
from front of engine) is: 1 notch, 2 notches, 3 notches,
Fig. 5 PDC LOCATION
1 - BATTERY
2 - PDC (POWER DISTRIBUTION CENTER)
8I - 8 IGNITION CONTROLDR
AUTOMATIC SHUT DOWN RELAY (Continued)

3 notches, 2 notches 1 notch, 3 notches and 1 notch.
The signal from the CMP sensor is used in conjunc-
tion with the crankshaft position sensor to differenti-
ate between fuel injection and spark events. It is also
used to synchronize the fuel injectors with their
respective cylinders.
5.7L V-8
The CMP sensor is used in conjunction with the
crankshaft position sensor to differentiate between
fuel injection and spark events. It is also used to syn-
chronize the fuel injectors with their respective cylin-
ders. The sensor generates electrical pulses. These
pulses (signals) are sent to the Powertrain Control
Module (PCM). The PCM will then determine crank-
shaft position from both the camshaft position sensor
and crankshaft position sensor.
The tonewheel is located at the front of the cam-
shaft (Fig. 8). As the tonewheel rotates, notches (Fig.
8) pass through the sync signal generator.
When the cam gear is rotating, the sensor will
detect the notches. Input voltage from the sensor to
the PCM will then switch from a low (approximately
0.3 volts) to a high (approximately 5 volts). When the
sensor detects a notch has passed, the input voltage
switches back low to approximately 0.3 volts.
Fig. 6 CMP OPERATION- 3.7L V-6
1 - NOTCHES
2 - RIGHT CYLINDER HEAD
3 - CMP
4 - TONEWHEEL (TARGET WHEEL)
Fig. 7 CMP AND TONEWHEEL OPERATION - 4.7L
V-8
1 - NOTCHES
2 - RIGHT CYLINDER HEAD
3 - CAMSHAFT POSITION SENSOR
4 - TONEWHEEL
Fig. 8 CMP OPERATION - 5.7L ENGINE
1 - TIMING CHAIN COVER
2 - TONEWHEEL
3 - NOTCHES
DRIGNITION CONTROL 8I - 9
CAMSHAFT POSITION SENSOR (Continued)