2003 DODGE RAM air filter

Miles 3,000 6,000 9,000 12,000 15,000
(Kilometers) (5 000) (10 000) (14 000) (19 000) (24 000)
Change engine oil and engine oil filter.XXXX X
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XX
Change rear axle fluid.X
Change front axle fluid (4X4).X
Inspect brake linings.X
Inspect engine air cleaner filter, replace
if necessary.X
Miles 18,000 21,000 24,000 27,000 30,000
(Kilometers) (29 000) (34 000) (38 000) (43 000) (48 000)
Change engine oil and engine oil filter.XXXX X
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XX X
Change rear axle fluid.X
Change front axle fluid (4X4).X
Inspect brake linings. X
Inspect engine air cleaner filter, replace
if necessary.X
Replace spark plugs.X
Inspect PCV valve, replace as necessary.X*
Drain and refill automatic tranmission fluid,
change filter and adjust bands (46RE/47RE/
48RE).³X
Drain and refill automatic tranmission fluid
and change main sump filter (45RFE/
545RFE only).³X
Miles 33,000 36,000 39, 000 42,000 45,000
(Kilometers) (53 000) (58 000) (62 000) (67 000) (72 000)
Change engine oil and engine oil filter.XXXX X
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XX
Change rear axle fluid.X
Change front axle fluid (4X4).X
Inspect brake linings. X
Inspect engine air cleaner filter, replace
if necessary.X
DRLUBRICATION & MAINTENANCE 0 - 7
MAINTENANCE SCHEDULES (Continued)

Miles 48,000 51,000 54,000 57,000 60,000
(Kilometers) (77 000) (82 000) (86 000) (91 000) (96 000)
Change engine oil and engine oil filter.XXXX X
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XXX
Drain and refill transfer case fluid.X
Change rear axle fluid.X
Change front axle fluid (4X4).X
Inspect brake linings. X X
Inspect engine air cleaner filter, replace
if necessary.X
Replace spark plugs.X
Replace ignition cables (5.7L/5.9L/8.0L).X
Inspect PCV valve, replace as necessary.X*
Drain and refill automatic tranmission fluid,
change filter and adjust bands (46RE/47RE/
48RE).X
Drain and refill automatic tranmission fluid
and change main sump filter (45RFE/
545RFE only).X
Miles 63,000 66,000 69,000 72,000 75,000
(Kilometers) (101 000) (106 000) (110 000) (115 000) (120 000)
Change engine oil and engine oil filter.XXXX
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XX
Inspect engine air cleaner filter.X
Change rear axle fluid.X
Change front axle fluid (4X4).X
Inspect brake linings.X
Inspect auto tension drive belt and replace
if required (3.7L/4.7L/5.7L/5.9L/8.0L).X
0 - 8 LUBRICATION & MAINTENANCEDR
MAINTENANCE SCHEDULES (Continued)

Miles 78,000 81,000 84,000 87,000 90,000
(Kilometers) (125 000) (130 000) (134 000) (139 000) (144 000)
Change engine oil and engine oil filter.XXXX X
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XXX
Change rear axle fluid.X
Change front axle fluid (4X4).X
Inspect brake linings. X
Inspect engine air cleaner filter, replace
if necessary.X
Replace spark plugs.X
Inspect PCV valve, replace as necessary.X*
Inspect auto tension drive belt and replace
if required (3.7L/4.7L/5.7L/5.9L/8.0L).X³
Drain and refill automatic tranmission fluid,
change filter and adjust bands (46RE/47RE/
48RE).X
Drain and refill automatic tranmission fluid
and change main sump and spin-on cooler
return filter (if equipped) [45RFE/545RFE
only].X
Miles 93,000 96,000 99,000 100,000 102,000
(Kilometers) (149 000) (154 000) (158 000) (160 000) (163 000)
Change engine oil and engine oil filter. X X X X
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XX
Flush and replace engine coolant. X
Flush and replace Power Steering Fluid. X
Inspect brake linings. X
DRLUBRICATION & MAINTENANCE 0 - 9
MAINTENANCE SCHEDULES (Continued)

Miles 105,000 108,000 111,000 114,000 117,000 120,000
(Kilometers) (168 000) (173 000) (178 000) (182 000) (187 000) (192 000)
Change engine oil and engine
oil filter.XXXXX X
Lubricate outer tie rod ends
2500/3500 (4X4) models only.XXX
Drain and refill transfer case
fluid.X
Change rear axle fluid. X X
Change front axle fluid (4X4). X X
Inspect brake linings. X X
Inspect engine air cleaner
filter, replace if necessary.XX
Replace spark plugs.X
Replace ignition cables
(5.7L/5.9L/8.0L).X
Inspect PCV valve, replace
as necessary.X*
Inspect auto tension drive belt
and replace if required
(3.7L/4.7L/5.7L/5.9L/8.0L).X³ X³
Drain and refill automatic
tranmission fluid, change filter
and adjust bands (46RE/
47RE/48RE).X
Drain and refill automatic
tranmission fluid and change
main sump filter (45RFE/
545RFE only).X
* This maintenance is recommended by the manu-
facture to the owner but is not required to maintain
the emissions warranty.
³ This maintenance is not required if previously
replaced.
Inspection and service should also be performed
anytime a malfunction is observed or suspected.
Retain all receipts.
0 - 10 LUBRICATION & MAINTENANCEDR
MAINTENANCE SCHEDULES (Continued)

Schedule ªAº
Miles 6,000 12,000 18,000 24,000 30,000
(Kilometers) (10 000) (19 000) (29 000) (38 000) (48 000)
[Months] [6] [12] [18] [24] [30]
Change engine oil and engine oil filter.XXXX X
Check transfer case fluid level.X
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XXXX X
Inspect brake linings. X
Replace engine air cleaner filter.X
Replace spark plugs.X
Miles 36,000 42,000 48,000 54,000 60,000 66,000
(Kilometers) (58 000) (67 000) (77 000) (84 000) (96 000) (106 000)
[Months] [36] [42] [48] [54] [60] [66]
Change engine oil and engine
oil filter.XXXXX
X
Check transfer case fluid
level.X
Lubricate outer tie rod ends
2500/3500 (4X4) models only.XXXXX X
Flush and replace engine
coolant at 60 months,
regardless of mileage.X
Inspect brake linings. X X
Replace engine air cleaner
filter.X
Replace spark plugs.X
Inspect PCV valve, replace
as necessary.X*
Replace ignition cables
(5.7L/5.9L/8.0L).X
DRLUBRICATION & MAINTENANCE 0 - 11
MAINTENANCE SCHEDULES (Continued)

Miles 72,000 78,000 84,000 90,000 96,000 100,000
(Kilometers) (115 000) (125 000) (134 000) (144 000) (154 000) (160 000)
[Months] [72] [78] [84] [90] [96]
Change engine oil and engine oil filter.XXXXX
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XXXXX
Drain and refill transfer case fluid. X
Flush and replace engine coolant, if not
done at 60 mos.X
Flush and replace Power Steering Fluid.X
Inspect brake linings. X X
Replace engine air cleaner filter.X
Replace spark plugs.X
Replace ignition cables (5.7L/5.9L/
8.0L).X
Inspect PCV valve, replace as
necessary.X*
Inspect auto tension drive belt and
replace if required (3.7L/4.7L/5.7L/5.9L/
8.0L).X
Drain and refill automatic tranmission
fluid, change filter and adjust bands
(46RE/47RE/48RE).X
Drain and refill automatic tranmission
fluid and change main sump filter and
spin-on cooler return filter (if equipped)
[45RFE/545RFE only].X
Miles 102,000 108,000 114,000 120,000
(Kilometers) (163 000) (173 000) (182 000) (192 000)
[Months] [102] [108] [114] [120]
Change engine oil and engine oil filter. X X X X
Check transfer case fluid level.X
Lubricate outer tie rod ends 2500/3500 (4X4) models only. X X X X
Inspect brake linings. X
Inspect auto tension drive belt and replace if required
(3.7L/4.7L/5.7L/5.9L/8.0L).X³X³
Replace engine air cleaner filter.X
Replace spark plugs.X
* This maintenance is recommended by the manu-
facture to the owner but is not required to maintain
the emissions warranty.
³ This maintenance is not required if previously
replaced.
Inspection and service should also be performed
anytime a malfunction is observed or suspected.
Retain all receipts.WARNING: You can be badly injured working on or
around a motor vehicle. Do only that service work
for which you have the knowledge and the right
equipment. If you have any doubt about your ability
to perform a service job, take your vehicle to a
competent mechanic.
0 - 12 LUBRICATION & MAINTENANCEDR
MAINTENANCE SCHEDULES (Continued)

INSTALLATION
(1) Install antenna cable to radio.
(2) Connect electrical harness connector to radio.
(3) Install radio to instrument panel.
(4) Install instrument panel center bezel (Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL CENTER BEZEL - INSTALLATION).
(5) Connect battery negative cable.
RADIO NOISE SUPPRESSION
GROUND STRAP
DESCRIPTION
Radio noise suppression devices are factory-in-
stalled standard equipment on this vehicle. Radio
Frequency Interference (RFI) and ElectroMagnetic
Interference (EMI) can be produced by any on-board
or external source of electromagnetic energy. These
electromagnetic energy sources can radiate electro-
magnetic signals through the air, or conduct them
through the vehicle electrical system.
When the audio system converts RFI or EMI to an
audible acoustic wave form, it is referred to as radio
noise. This undesirable radio noise is generally man-
ifested in the form of ªbuzzing,º ªhissing,º ªpopping,º
ªclicking,º ªcrackling,º and/or ªwhirringº sounds. In
most cases, RFI and EMI radio noise can be sup-
pressed using a combination of vehicle and compo-
nent grounding, filtering and shielding techniques.
This vehicle is equipped with factory-installed radio
noise suppression devices that were designed to min-
imize exposure to typical sources of RFI and EMI;
thereby, minimizing radio noise complaints.Factory-installed radio noise suppression is accom-
plished primarily through circuitry or devices that
are integral to the factory-installed radios, audio
power amplifiers and other on-board electrical com-
ponents such as generators, wiper motors, blower
motors, and fuel pumps that have been found to be
potential sources of RFI or EMI. External radio noise
suppression devices that are used on this vehicle to
control RFI or EMI, and can be serviced, include the
following:
²Engine-to-body ground strap- This length of
braided ground strap has an eyelet terminal connec-
tor crimped to each end. One end is secured to the
engine cylinder head(s). The other is secured to the
plenum at the exhaust heat shield forward/outer
attaching stud.
²Resistor-type spark plugs- This type of spark
plug has an internal resistor connected in series
between the spark plug terminal and the center elec-
trode to help reduce the production of electromag-
netic radiation that can result in radio noise.
OPERATION
There are two common strategies that can be used
to suppress Radio Frequency Interference (RFI) and
ElectroMagnetic Interference (EMI) radio noise. The
first suppression strategy involves preventing the
production of RFI and EMI electromagnetic signals
at their sources. The second suppression strategy
involves preventing the reception of RFI and EMI
electromagnetic signals by the audio system compo-
nents.
The use of braided ground straps in key locations
is part of the RFI and EMI prevention strategy.
These ground straps ensure adequate ground paths,
particularly for high current components such as
many of those found in the starting, charging, igni-
tion, engine control and transmission control sys-
tems. An insufficient ground path for any of these
high current components may result in radio noise
caused by induced voltages created as the high cur-
rent seeks alternative ground paths through compo-
nents or circuits intended for use by, or in close
proximity to the audio system components or circuits.
Preventing the reception of RFI and EMI is accom-
plished by ensuring that the audio system compo-
nents are correctly installed in the vehicle. Loose,
corroded or improperly soldered wire harness connec-
tions, improperly routed wiring and inadequate audio
system component grounding can all contribute to
the reception of RFI and EMI. A properly grounded
antenna body and radio chassis, as well as a shielded
antenna coaxial cable with clean and tight connec-
tions will each help reduce the potential for reception
of RFI and EMI.
Fig. 7 ANTENNA TO RADIO
1 - RADIO
2 - LOCKING ANTENNA CONNECTOR
3 - INSTRUMENT PANEL ANTENNA CABLE
8A - 8 AUDIODR
RADIO (Continued)

ENGINE CONTROL MODULE
DESCRIPTION - ECM
The Engine Control Module (ECM) is bolted to the
left side of the engine below the intake manifold (Fig.
2).
OPERATION - ECM
The main function of the Engine Control Module
(ECM) is to electrically control the fuel system. The
Powertrain Control Module (PCM)does not control
the 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
²APPS1 Signal Ð For off engine APPS
²APPS2 Signal Ð For off engine APPS
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
²Engine Coolant Temperature (ECT) sensor
²Ground circuits
²Fuel Pressure Sensor
²Battery Temperature
²Fan speed
²Inlet Air Temperature Sensor/Pressure Sensor
²Intake Air Temperature Sensor/MAP Sensor
²Oil Pressure SWITCH
²Power ground
²Sensor return
²Signal ground
²Water-In-Fuel (WIF) sensor
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 transfer (lift) pump
²Intake manifold air heater relays #1 and #2 con-
trol circuits
²Malfunction indicator lamp (Check engine lamp)
(databus)
²Oil Pressure Swith/warning lamp (databus)
²Fuel Control Actuator
²Wait-to-start warning lamp (databus)
²Fan Clutch PWM
²Water-In-Fuel (WIF) warning lamp (databus)
REMOVAL
The Engine Control Module (ECM) is bolted to a
support bracket near the fuel filter. The support
bracket mounts to the block with four capscrews and
vibration isolators. A ground wire is fastened to the
bracket. The other end of the wire is fastened to the
engine block.
(1) Record any Diagnostic Trouble Codes (DTC's)
found in the ECM.
Fig. 2 DIESEL ECM
1 - ENGINE CONTROL MODULE (ECM)
2 - ECM MOUNTING BOLT
3 - 50-WAY CONNECTOR
4 - SUPPORT PLATE
5 - 60-WAY CONNECTOR
8E - 4 ELECTRONIC CONTROL MODULESDR