engine DODGE RAM 2003 Service Repair Manual

Fig. 27 LEFT SIDE ENGINE COMPARTMENT
8W - 91 - 38 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONDR
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

Fig. 28 LEFT SIDE ENGINE COMPARTMENT
DR8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 39
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

Fig. 29 LEFT SIDE ENGINE COMPARTMENT
8W - 91 - 40 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONDR
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

Fig. 31 LEFT SIDE ENGINE COMPARTMENT AND HOOD
8W - 91 - 42 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONDR
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

INTEGRATED POWER MODULE
DESCRIPTION
The Integrated Power Module (IPM) (Fig. 1) is a
combination of the Power Distribution Center (PDC)
and the Front Control Module (FCM). The IPM is
located in the engine compartment, next to the bat-
tery on this model. The power distribution center
mates directly with the Front Control Module (FCM)
to form the Integrated Power Module Fuse and Relay
Center. The power distribution center (PDC) is a
printed circuit board based module that contains
fuses and relays, while the front control module con-
tains the electronics controlling the integrated power
module and other functions. This integrated power
module connects directly to the battery positive via a
stud located on top of the unit. The ground connec-
tion is via electrical connectors. The integrated power
module provides the primary means of voltage distri-
bution and protection for the entire vehicle.
The molded plastic integrated power module hous-
ing includes a base and cover. The integrated power
module cover is easily opened or removed for service
access by unscrewing the cover retaining nut and has
a fuse and relay layout map integral to the inside
surface of the cover. This integrated power module
housing base and cover are secured in place via bolts
to the left front fender support assembly.
Replaceable components of the integrated power
module assembly are broken down into the followingcomponents: the Power Distribution Center (PDC),
the integrated power module cover, the Front Control
Module (FCM) and the Integrated Power Module
Assembly which includes the power distribution cen-
ter, the cover and FCM.Refer to the Front Con-
trol Module in the Electronic Control Module
sectionof this service manual for information on the
front control module.
OPERATION
All of the current from the battery and the gener-
ator output enters the integrated power module via a
stud on the top of the module. The integrated power
module cover is removed to access the fuses or relays.
Internal connections of all of the power distribution
center circuits is accomplished by a combination of
bus bars and a printed circuit board. Refer to the
Wiring section of the service manual for complete
integrated power module circuit schematics.
REMOVAL
(1) Disconnect the negative and positive battery
cables.
(2) Unsnap cover and remove the B+ terminal nut
from the integrated power module B+ terminal.
Remove the B+ cable from the integrated power mod-
ule.
(3) Disconnect the gray connector from the inte-
grated power module.
Fig. 1 DR INTEGRATED POWER MODULE
1 - POWER DISTRIBUTION CENTER HOUSING
2 - FRONT CONTROL MODULE ELECTRICAL CONNECTOR
Fig. 2 DR INTEGRATED POWER MODULE
1 - COVER RETAINING BOLT
2 - INTEGRATED POWER MODULE RETAINING BOLT
3 - RETAINING SCREW
4 - INTEGRATED POWER MODULE COVER
DR8W-97 POWER DISTRIBUTION 8W - 97 - 3

(4) Remove the integrated power module retaining
bolt and screw (Fig. 2).
(5) Grasp the integrated power module with two
hands and slide the assembly in the direction shown
(Fig. 3) to free the module from its mounting bracket.
Position the assembly upside down to access the elec-
trical connectors located on the bottom of the unit.
(6) Disconnect the electrical connectors by depress-
ing the locking tab and rotating the connector arm
outboard, until the connector is free from the module
assembly. Be certain to pull the connectors straight
off.
(7) Position the integrated power module on a
bench and remove the four front control module
retaining screws.
(8) Disconnect the front control module by pulling
it straight off the integrated power module.
INSTALLATION
(1) Connect the front control module by pushing it
straight on the integrated power module electrical
receptacle.
(2) Install the four front control module retaining
screws. Torque to 30 in. lbs. +/-5.
NOTE: Integrated power module electrical connec-
tors are color coded to ease location reference (Fig.
4).
(3) Connect the electrical connectors by pushing
straight on and rotating the connector arm inboard,
until the connector is firmly locked in place on the
module assembly.(4) Grasp the integrated power module with two
hands and install the assembly on the battery tray
(Fig. 5).
(5) Install the integrated power module retaining
bolt and screw.
(6) Connect the gray connector on the integrated
power module housing.
(7) Install the B+ terminal cable and nut on the
integrated power module B+ terminal. Snap the
cover in place.
(8) Connect the negative and positive battery
cables.
FRONT CONTROL MODULE
DESCRIPTION
The Front Control Module (FCM) is a micro con-
troller based module located in the left front corner
of the engine compartment. On this model the inte-
grated power module must be positioned aside in
order to access the front control module. The front
control module mates to the power distribution cen-
ter to form the Integrated Power Module (IPM). The
integrated power module connects directly to the bat-
Fig. 3 REMOVING INTEGRATED POWER MODULE
Fig. 4 INTEGRATED POWER MODULE ELECTRICAL
CONNECTIONS
1 - RETAINING LATCH
2 - GRAY CONNECTOR
3 - GREEN CONNECTOR
4 - GREEN CONNECTOR
5 - BLUE CONNECTOR
6 - WHITE CONNECTOR
7 - BLACK CONNECTOR
8 - BLACK CONNECTOR
8W - 97 - 4 8W-97 POWER DISTRIBUTIONDR
INTEGRATED POWER MODULE (Continued)

tery and provides the primary means of circuit pro-
tection and power distribution for all vehicle
electrical systems. The front control module controls
power to some of these vehicle systems electrical and
electromechanical loads based on inputs received
from hard wired switch inputs and data received on
the PCI bus circuit (J1850).
For information on theIntegrated Power Mod-
ule Refer to the Power Distribution Sectionof
the service manual.
OPERATION
As messages are sent over the PCI bus circuit, the
front control module reads these messages and con-
trols power to some of the vehicles electrical systems
by completing the circuit to ground (low side driver)
or completing the circuit to 12 volt power (high side
driver). The following functions areControlledby
the Front Control Module:
²Headlamp Power with Voltage Regulation
²Windshield Wiper ªON/OFFº Relay Actuation
²Windshield Wiper ªHI/LOº Relay Actuation
²Windshield Washer Pump Motor
²Fog Lamp Relay Actuation
²Park Lamp Relay Actuation
²Horn Relay Actuation
The following inputs areReceived/Monitoredby
the Front Control Module:
²B+ Connection Detection²Power Ground
²Ambient Temperature Sensing
²Ignition Switch Run
²Washer Fluid Level Switch
²Windshield Wiper Park Switch
²PCI Bus Circuit
DIAGNOSIS AND TESTING - FRONT CONTROL
MODULE
The front control module is a printed circuit board
based module with a on-board micro-processor. The
front control module interfaces with other electronic
modules in the vehicle via the Programmable Com-
munications Interface (PCI) data bus (J1850). In
order to obtain conclusive testing the Programmable
Communications Interface (PCI) data bus network
and all of the electronic modules that provide inputs
to, or receive outputs from the front control module
must be checked. All PCI (J1850) communication
faults must be resolved prior to further diagnosing
any front control module related issues.
The front control module was designed to be diag-
nosed with an appropriate diagnostic scan tool, such
as the DRB IIIt. The most reliable, efficient, and
accurate means to diagnose the front control module
requires the use of a DRB IIItscan tool and the
proper Body Diagnostic Procedures manual.
Before any testing of the front control module is
attempted, the battery should be fully charged and
all wire harness and ground connections inspected
around the affected areas on the vehicle.
REMOVAL
(1) Disconnect the positive and negative battery
cables from the battery.
(2) Partially remove the integrated power module
from the engine compartment (Refer to 8 - ELECTRI-
CAL/POWER DISTRIBUTION/INTEGRATED
POWER MODULE - REMOVAL).
(3)
Remove the front control module retaining
screws.
(4) Using both hands, pull the front control module
straightfrom the integrated power module assembly
to disconnect the 49-way electrical connector and
remove the front control module from the vehicle.
INSTALLATION
(1) Install the front control module on the inte-
grated power module assembly by pushing the
49-way electrical connector straight in.
(2) Install the front control module retaining
screws. Torque the screws to 7 in. lbs.
(3) Install the integrated power module (Refer to 8
- ELECTRICAL/POWER DISTRIBUTION/INTE-
GRATED POWER MODULE - INSTALLATION).
(4)
Connect the positive and negative battery cables.
Fig. 5 INTEGRATED POWER MODULE MOUNTING
TABS
1 - INTEGRATED POWER MODULE MOUNTING HOLES
2 - BATTERY TRAY ASSEMBLY
3 - FRONT CONTROL MODULE
DR8W-97 POWER DISTRIBUTION 8W - 97 - 5
FRONT CONTROL MODULE (Continued)

ENGINE
TABLE OF CONTENTS
page page
ENGINE - 3.7L............................ 1
ENGINE - 4.7L........................... 87
ENGINE - 5.7L.......................... 176ENGINE - 5.9L.......................... 223
ENGINE 5.9L DIESEL..................... 280
ENGINE 8.0L............................ 351
ENGINE - 3.7L
TABLE OF CONTENTS
page page
ENGINE - 3.7L
DESCRIPTION..........................3
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION............4
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - PERFORMANCE............4
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - MECHANICAL..............6
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - LUBRICATION..............7
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE..............8
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE.......8
STANDARD PROCEDURE
STANDARD PROCEDURE - REPAIR
DAMAGED OR WORN THREADS..........9
STANDARD PROCEDURE - FORM-IN-
PLACE GASKETS AND SEALERS..........9
STANDARD PROCEDURE - ENGINE
GASKET SURFACE PREPARATION........10
REMOVAL.............................10
INSTALLATION.........................11
SPECIFICATIONS
SPECIFICATIONS ± 3.7L ENGINE.........12
TORQUE............................15
SPECIAL TOOLS.......................16
AIR CLEANER ELEMENT
REMOVAL.............................20
INSTALLATION.........................20
CYLINDER HEAD - LEFT
DIAGNOSIS AND TESTING - CYLINDER HEAD
GASKET............................20
REMOVAL.............................21
INSTALLATION.........................23CAMSHAFT(S)
DESCRIPTION.........................24
REMOVAL.............................24
INSTALLATION.........................25
CYLINDER HEAD COVER(S)
DESCRIPTION.........................26
REMOVAL.............................26
INSTALLATION.........................27
INTAKE/EXHAUST VALVES & SEATS
DESCRIPTION.........................27
STANDARD PROCEDURE - REFACING......27
REMOVAL.............................28
INSTALLATION.........................29
ROCKER ARM
DESCRIPTION.........................30
REMOVAL.............................30
INSTALLATION.........................30
VALVE GUIDE SEALS
DESCRIPTION.........................31
VALVE SPRINGS
DESCRIPTION.........................31
REMOVAL.............................31
INSTALLATION.........................31
CYLINDER HEAD - RIGHT
DIAGNOSIS AND TESTING - HYDRAULIC
LASH ADJUSTER.....................31
REMOVAL.............................32
INSTALLATION.........................32
CAMSHAFT(S)
DESCRIPTION.........................34
REMOVAL.............................34
INSTALLATION.........................35
CYLINDER HEAD COVER(S)
REMOVAL.............................35
INSTALLATION.........................36
DRENGINE 9 - 1

ROCKER ARM
DESCRIPTION.........................36
REMOVAL.............................36
VALVE GUIDE SEALS
DESCRIPTION.........................36
VALVE SPRINGS
DESCRIPTION.........................36
REMOVAL.............................37
INSTALLATION.........................37
ENGINE BLOCK
DESCRIPTION.........................37
STANDARD PROCEDUREÐCYLINDER BORE
HONING............................37
CLEANING............................38
INSPECTION..........................38
CRANKSHAFT
DESCRIPTION.........................39
REMOVAL.............................39
INSPECTION..........................40
INSTALLATION.........................41
CRANKSHAFT MAIN BEARINGS
STANDARD PROCEDURE
MAIN BEARING FITTING................43
CRANKSHAFT OIL SEAL - FRONT
REMOVAL.............................44
INSTALLATION.........................45
CRANKSHAFT OIL SEAL - REAR
REMOVAL.............................45
INSTALLATION.........................46
FLEX PLATE
REMOVAL.............................47
INSTALLATION.........................47
PISTON & CONNECTING ROD
DESCRIPTION.........................47
STANDARD PROCEDURE
CONNECTING ROD BEARING FITTING....48
STANDARD PROCEDUREÐPISTON
FITTING.............................50
REMOVAL.............................50
CLEANING............................51
INSPECTION..........................51
INSTALLATION.........................51
PISTON RINGS
STANDARD PROCEDURE - PISTON RING
FITTING.............................52
VIBRATION DAMPER
REMOVAL.............................54
INSTALLATION.........................55
STRUCTURAL COVER
DESCRIPTION.........................56
OPERATION...........................56
REMOVAL.............................56
INSTALLATION.........................56
FRONT MOUNT
REMOVAL.............................57
INSTALLATION.........................58REAR MOUNT
REMOVAL.............................60
INSTALLATION.........................60
LUBRICATION
DESCRIPTION.........................60
OPERATION...........................60
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐENGINE OIL
LEAK...............................63
DIAGNOSIS AND TESTING - CHECKING
ENGINE OIL PRESSURE................64
DIAGNOSIS AND TESTING - REAR SEAL
AREA LEAKS.........................64
OIL PAN
DESCRIPTION.........................65
REMOVAL.............................65
CLEANING............................65
INSPECTION..........................66
INSTALLATION.........................66
OIL PRESSURE SENSOR/SWITCH
DESCRIPTION.........................66
OPERATION...........................66
REMOVAL.............................67
INSTALLATION.........................67
OIL PUMP
REMOVAL.............................67
DISASSEMBLY.........................67
INSPECTION..........................67
ASSEMBLY............................68
INSTALLATION.........................68
OIL FILTER
REMOVAL.............................69
INSTALLATION.........................70
OIL
STANDARD PROCEDURE - ENGINE OIL
SERVICE............................70
INTAKE MANIFOLD
DESCRIPTION.........................71
DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKS.....................71
REMOVAL.............................72
INSTALLATION.........................72
EXHAUST MANIFOLD
DESCRIPTION.........................73
REMOVAL.............................73
INSTALLATION.........................74
VALVE TIMING
DESCRIPTION.........................75
OPERATION...........................75
STANDARD PROCEDURE
MEASURING TIMING CHAIN WEAR.......76
SERVICE PROCEDURE - TIMING
VERIFICATION........................76
BALANCE SHAFT
REMOVAL.............................79
INSTALLATION.........................79
9 - 2 ENGINE - 3.7LDR

IDLER SHAFT
REMOVAL.............................79
INSTALLATION.........................80
TIMING BELT / CHAIN COVER(S)
REMOVAL.............................80INSTALLATION.........................81
TIMING BELT/CHAIN AND SPROCKETS
REMOVAL.............................81
INSPECTION..........................83
INSTALLATION.........................84
ENGINE - 3.7L
DESCRIPTION
The 3.7 liter (226 CID) six-cylinder engine is an
90É single overhead camshaft engine (Fig. 1). The
cast iron cylinder block is made up of two different
components; the first component is the cylinder bore
and upper block, the second component is the bed-
plate that comprises the lower portion of the cylinderblock and houses the lower half of the crankshaft
main bearings. The cylinders are numbered from
front to rear with the left bank being numbered 1,3,
and 5 and the right bank being numbered 2,4, and 6.
The firing order is 1±6±5±4±3±2. The engine serial
number is located at the right front side of the
engine block
Fig. 1 3.7 L ENGINE
DRENGINE - 3.7L 9 - 3