2003 DODGE RAM ECU

ELECTRONIC MODULE IGNITION-OFF DRAW (IOD) TABLE
ModuleTime Out?
(If Yes, Interval And Wake-Up Input)IODIOD After Time
Out
ElectroMechanical
Instrument Cluster
(EMIC)No 0.44 milliampere N/A
Combination Flasher No 0.08 milliampere N/A
(2) Determine that the underhood lamp is operat-
ing properly, then disconnect the lamp wire harness
connector or remove the lamp bulb.
(3) Disconnect the battery negative cable.
(4) Set an electronic digital multi-meter to its
highest amperage scale. Connect the multi-meter
between the disconnected battery negative cable ter-
minal clamp and the battery negative terminal post.
Make sure that the doors remain closed so that the
illuminated entry system is not activated. The multi-
meter amperage reading may remain high for up to
three minutes, or may not give any reading at all
while set in the highest amperage scale, depending
upon the electrical equipment in the vehicle. The
multi-meter leads must be securely clamped to the
battery negative cable terminal clamp and the bat-
tery negative terminal post. If continuity between the
battery negative terminal post and the negative cable
terminal clamp is lost during any part of the IOD
test, the electronic timer function will be activated
and all of the tests will have to be repeated.
(5) After about three minutes, the high-amperage
IOD reading on the multi-meter should become very
low or nonexistent, depending upon the electrical
equipment in the vehicle. If the amperage reading
remains high, remove and replace each fuse or circuit
breaker in the Integrated Power Module (IPM), one
at a time until the amperage reading becomes very
low, or nonexistent. Refer to the appropriate wiring
information in this service manual for complete Inte-
grated Power Module fuse, circuit breaker, and cir-
cuit identification. This will isolate each circuit and
identify the circuit that is the source of the high-am-
perage IOD. If the amperage reading remains high
after removing and replacing each fuse and circuit
breaker, disconnect the wire harness from the gener-
ator. If the amperage reading now becomes very low
or nonexistent, refer to Charging System for the
proper charging system diagnosis and testing proce-
dures. After the high-amperage IOD has been cor-
rected, switch the multi-meter to progressively lower
amperage scales and, if necessary, repeat the fuse
and circuit breaker remove-and-replace process to
identify and correct all sources of excessive IOD. It is
now safe to select the lowest milliampere scale of the
multi-meter to check the low-amperage IOD.CAUTION: Do not open any doors, or turn on any
electrical accessories with the lowest milliampere
scale selected, or the multi-meter may be damaged.
(6) Observe the multi-meter reading. The low-am-
perage IOD should not exceed thirty-five milliam-
peres (0.035 ampere). If the current draw exceeds
thirty-five milliamperes, isolate each circuit using the
fuse and circuit breaker remove-and-replace process
in Step 5. The multi-meter reading will drop to
within the acceptable limit when the source of the
excessive current draw is disconnected. Repair this
circuit as required; whether a wiring short, incorrect
switch adjustment, or a component failure is at fault.
STANDARD PROCEDURE - USING MICRO 420
BATTERY TESTER
Always use the Micro 420 Instruction Manual that
was supplied with the tester as a reference. If the
Instruction Manual is not available the following pro-
cedure can be used:
Fig. 9 MICRO 420 BATTERY TESTER
8F - 12 BATTERY SYSTEMDR
BATTERY (Continued)

(7) Remove the battery from the battery tray.
INSTALLATION
(1) Clean and inspect the battery.
(2) Position the battery onto the battery tray.
Ensure that the battery positive and negative termi-
nal posts are correctly positioned. The battery cable
terminal clamps must reach the correct battery ter-
minal post without stretching the cables.
(3) Position the battery hold down and install the
retaining bolt.
CAUTION: Be certain that the battery cable terminal
clamps are connected to the correct battery termi-
nal posts. Reversed battery polarity may damage
electrical components of the vehicle.
(4) Clean the battery cable terminal clamps and
the battery terminal posts.
(5) Reconnect the battery positive cable terminal
clamp to the battery positive terminal post. Tighten
the terminal clamp pinch-bolt hex nut to 4 N´m (35
in. lbs.).
(6) Reconnect the battery negative cable terminal
clamp to the battery negative terminal post. Tighten
the terminal clamp pinch-bolt hex nut to 4 N´m (35
in. lbs.).
(7) Apply a thin coating of petroleum jelly or chas-
sis grease to the exposed surfaces of the battery cable
terminal clamps and the battery terminal posts.
(8) Obtain a DRB IIItscan tool and check the
PCM for any stored battery disconnect trouble code,
if required.
BATTERY HOLDDOWN
DESCRIPTION
The battery hold down hardware includes a bolt
and a molded plastic hold down bracket which
meshes with the battery tray when properly
installed. The battery tray and hold down hardware
combine to form a very stable and secure battery
hold down assembly.
OPERATION
The battery holddown secures the battery in the
battery tray. This holddown is designed to prevent
battery movement during the most extreme vehicle
operation conditions. Periodic removal and lubrica-
tion of the battery holddown hardware is recom-
mended to prevent hardware seizure at a later date.
CAUTION: Never operate a vehicle without a battery
holddown device properly installed. Damage to the
vehicle, components and battery could result.
REMOVAL
(1) Loosen and remove the battery hold down
retaining bolt.
(2) Remove the battery hold down bracket from
the battery case.
INSTALLATION
(1) Clean and inspect the battery hold down hard-
ware (Refer to 8 - ELECTRICAL/BATTERY SYSTEM
- CLEANING).
(2) Position the battery hold down bracket in the
battery tray. Be certain that the hold down bracket is
properly positioned in the battery tray before tight-
ening the hold down hardware.
(3) Install and tighten the battery hold down
retaining bolt.
BATTERY CABLES
DESCRIPTION
The battery cables are large gauge, stranded cop-
per wires sheathed within a heavy plastic or syn-
thetic rubber insulating jacket. The wire used in the
battery cables combines excellent flexibility and reli-
ability with high electrical current carrying capacity.
Refer to Wiring for the location of the proper battery
cable wire gauge information.
The battery cables cannot be repaired and, if dam-
aged or faulty they must be replaced. Both the bat-
tery positive and negative cables are available for
service replacement only as a unit with the battery
positive cable wire harness or the battery negative
cable wire harness, which may include portions of
the wiring circuits for the generator and other com-
ponents on some models.
Most models feature a stamped brass clamping
type female battery terminal crimped onto one end of
the battery cable wire and then solder-dipped. A
pinch-bolt and hex nut are installed at the open end
of the female battery terminal clamp. The battery
positive cable also includes a red molded rubber pro-
tective cover for the female battery terminal clamp.
Large eyelet type terminals are crimped onto the
opposite end of the battery cable wire and then sol-
der-dipped. The battery positive cable wires have a
red insulating jacket to provide visual identification
and feature a larger female battery terminal clamp
to allow connection to the larger battery positive ter-
minal post. The battery negative cable wires have a
black insulating jacket and a smaller female battery
terminal clamp.
OPERATION
The battery cables connect the battery terminal
posts to the vehicle electrical system. These cables
8F - 14 BATTERY SYSTEMDR
BATTERY (Continued)

also provide a return path for electrical current gen-
erated by the charging system for restoring the volt-
age potential of the battery. The female battery
terminal clamps on the ends of the battery cable
wires provide a strong and reliable connection of the
battery cable to the battery terminal posts. The ter-
minal pinch bolts allow the female terminal clamps
to be tightened around the male terminal posts on
the top of the battery. The eyelet terminals secured
to the ends of the battery cable wires opposite the
female battery terminal clamps provide secure and
reliable connection of the battery to the vehicle elec-
trical system.
DIAGNOSIS AND TESTING - BATTERY CABLES
A voltage drop test will determine if there is exces-
sive resistance in the battery cable terminal connec-
tions or the battery cables. If excessive resistance is
found in the battery cable connections, the connec-
tion point should be disassembled, cleaned of all cor-
rosion or foreign material, then reassembled.
Following reassembly, check the voltage drop for the
battery cable connection and the battery cable again
to confirm repair.
When performing the voltage drop test, it is impor-
tant to remember that the voltage drop is giving an
indication of the resistance between the two points at
which the voltmeter probes are attached.EXAM-
PLE:When testing the resistance of the battery pos-
itive cable, touch the voltmeter leads to the battery
positive cable terminal clamp and to the battery pos-
itive cable eyelet terminal at the starter solenoid
B(+) terminal stud. If you probe the battery positive
terminal post and the battery positive cable eyelet
terminal at the starter solenoid B(+) terminal stud,
you are reading the combined voltage drop in the
battery positive cable terminal clamp-to-terminal
post connection and the battery positive cable.
VOLTAGE DROP TEST
WARNING: MODELS EQUIPPED WITH A DIESEL
ENGINE HAVE AN AUTOMATIC SHUTDOWN (ASD)
RELAY LOCATED IN THE POWER DISTRIBUTION
CENTER (PDC). REMOVAL OF THE ASD RELAY
MAY NOT PREVENT THE DIESEL ENGINE FROM
STARTING. BE CERTAIN TO DISCONNECT THE
FUEL SHUTDOWN SOLENOID WIRE HARNESS
CONNECTOR TO PREVENT THE ENGINE FROM
STARTING. FAILURE TO DO SO MAY RESULT IN
PERSONAL INJURY.
The following operation will require a voltmeter
accurate to 1/10 (0.10) volt. Before performing this
test, be certain that the following procedures are
accomplished:²The battery is fully-charged and tested (Refer to
8 - ELECTRICAL/BATTERY SYSTEM/BATTERY -
STANDARD PROCEDURE).
²Fully engage the parking brake.
²If the vehicle is equipped with an automatic
transmission, place the gearshift selector lever in the
Park position. If the vehicle is equipped with a man-
ual transmission, place the gearshift selector lever in
the Neutral position and block the clutch pedal in the
fully depressed position.
²Verify that all lamps and accessories are turned
off.
²To prevent a gasoline engine from starting,
remove the Automatic ShutDown (ASD) relay. The
ASD relay is located in the Integrated Power Module
(IPM), in the engine compartment. See the fuse and
relay layout label on the underside of the IPM cover
for ASD relay identification and location.
(1) Connect the positive lead of the voltmeter to
the battery negative terminal post. Connect the neg-
ative lead of the voltmeter to the battery negative
cable terminal clamp (Fig. 11). Rotate and hold the
ignition switch in the Start position. Observe the
voltmeter. If voltage is detected, correct the poor con-
nection between the battery negative cable terminal
clamp and the battery negative terminal post.
NOTE: If the vehicle is equipped with two 12v bat-
teries, step #1 must be performed twice, once for
each battery.
(2) Connect the positive lead of the voltmeter to
the battery positive terminal post. Connect the nega-
tive lead of the voltmeter to the battery positive cable
terminal clamp (Fig. 12). Rotate and hold the ignition
switch in the Start position. Observe the voltmeter. If
voltage is detected, correct the poor connection
Fig. 11 Test Battery Negative Connection
Resistance - Typical
1 - VOLTMETER
2 - BATTERY
DRBATTERY SYSTEM 8F - 15
BATTERY CABLES (Continued)

INSTALLATION
(1) Position the battery cable in the engine com-
partment.
(2) One at a time, install the battery cable retain-
ing pushpins, fasteners and routing clips until the
cable is installed exactly where it was in the vehicle.
Refer to Wiring for illustrations.
(3) Install the battery in the vehicle. Refer to the
procedure in this group.
(4) Connect the battery negative cable terminal.
BATTERY TRAY
DESCRIPTION
The molded plastic tray battery tray is located in
the left front corner of the engine compartment. On
this model, the battery tray also provides an anchor
point for the anti-lock brake controller, cruise control
servo (if equipped) and the integrated power module
(Fig. 15). The battery hold down hardware is con-
tained within the battery tray. A hole in the bottom
of the battery tray is fitted with a battery tempera-
ture sensor. Refer to Charging System for more infor-
mation on the battery temperature sensor.
OPERATION
The battery tray and the battery hold down hard-
ware combine to secure and stabilize the battery in
the engine compartment, which prevents battery
movement during even the most extreme vehicle
operation. Unrestrained battery movement during
vehicle operation could result in damage to the vehi-
cle, the battery, or both.
REMOVAL
LEFT SIDE
(1) Remove the battery from the battery tray
(Refer to 8 - ELECTRICAL/BATTERY SYSTEM/BAT-
TERY - REMOVAL).
(2) Remove the integrated power module (Refer to
8 - ELECTRICAL/POWER DISTRIBUTION/INTEL-
LIGENT POWER MODULE - REMOVAL).
(3) Disconnect the wire harness retainers from the
battery tray assembly.
(4) Remove the anti-lock brake controller (if
equipped) retaining bolts and support the brake con-
troller with mechanics wire. It is not necessary to
completely remove the anti-lock brake control unit.
(5) Remove the left front wheelhouse splash shiel-
d(Refer to 23 - BODY/EXTERIOR/LF WHEEL-
HOUSE SPLASH SHIELD - REMOVAL).
Fig. 15 DR Battery Tray
1 - BATTERY TRAY ASSEMBLY
2 - BATTERY TEMPERATURE SENSOR
3 - ANTI-LOCK BRAKE CONTROLLER MOUNTING LOCATION
4 - INTEGRATED POWER MODULE MOUNTING SANCTION
Fig. 16 Lower Battery Tray Retaining Bolts
1 - BATTERY TRAY ASSEMBLY
2 - BATTERY TRAY RETAINING BOLTS
3 - CRUISE CONTROL SERVO
DRBATTERY SYSTEM 8F - 17
BATTERY CABLES (Continued)

SPECIFICATIONS - TORQUE - STARTING
SYSTEM
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Battery Cable Eyelet Nut at
Solenoid (large nut - gas engines)25 19 221
Battery Cable Eyelet Nut at
Solenoid (large nut - diesel engine)14 - 120
Starter Solenoid Nut (small nut -
diesel engine)6-55
Starter Mounting Bolts - Gas
Engines68 50 -
Starter Mounting Nut - Gas Engines 68 50 -
Starter Mounting Bolts - Diesel 43 32 -
STARTER MOTOR
DIAGNOSIS AND TESTING - STARTER MOTOR
Correct starter motor operation can be confirmed
by performing the following free running bench test.
This test can only be performed with starter motor
removed from vehicle. Refer to Specifications for
starter motor specifications.
(1) Remove starter motor from vehicle. Refer to
Starter Motor Removal and Installation.
(2) Mount starter motor securely in a soft-jawed
bench vise. The vise jaws should be clamped on the
mounting flange of starter motor. Never clamp on
starter motor by field frame.
(3) Connect a suitable volt-ampere tester and a
12-volt battery to starter motor in series, and set
ammeter to 100 ampere scale. See instructions pro-
vided by manufacturer of volt-ampere tester being
used.
(4) Install jumper wire from solenoid terminal to
solenoid battery terminal. The starter motor should
operate. If starter motor fails to operate, replace
faulty starter motor assembly.
(5) Adjust carbon pile load of tester to obtain free
running test voltage. Refer to Specifications for
starter motor free running test voltage specifications.
(6) Note reading on ammeter and compare reading
to free running test maximum amperage draw. Refer
to Specifications for starter motor free running test
maximum amperage draw specifications.
(7) If ammeter reading exceeds maximum amper-
age draw specification, replace faulty starter motor
assembly.
STARTER SOLENOID
This test can only be performed with starter motor
removed from vehicle.(1) Remove starter motor from vehicle. Refer to
Starter Motor Removal and Installation.
(2) Disconnect wire from solenoid field coil termi-
nal.
(3) Check for continuity between solenoid terminal
and solenoid field coil terminal with a continuity
tester (Fig. 7). There should be continuity. If OK, go
to Step 4. If not OK, replace faulty starter motor
assembly.
(4) Check for continuity between solenoid terminal
and solenoid case (Fig. 8). There should be continuity.
If not OK, replace faulty starter motor assembly.
REMOVAL
3.7L / 4.7L
(1) Disconnect and isolate negative battery cable.
(2) Raise and support vehicle.
(3) Note: If equipped with 4WD and certain trans-
missions, a support bracket is used between front
axle and side of transmission. Remove 2 support
bracket bolts at transmission. Pry support bracket
slightly to gain access to lower starter mounting bolt.
Fig. 7 CONTINUITY BETWEEN SOLENOID AND
FIELD COIL TERMINALS - TYPICAL
1 - OHMMETER
2 - SOLENOID TERMINAL
3 - FIELD COIL TERMINAL
8F - 34 STARTINGDR
STARTING (Continued)

(4) Remove 1 bolt and 1 nut if equipped with a
manual transmission (Fig. 9).
(5) Remove 2 bolts if equipped with an automatic
transmission (Fig. 10).
(6) Move starter motor towards front of vehicle far
enough for nose of starter pinion housing to clear
housing. Always support starter motor during this
process, do not let starter motor hang from wire har-
ness.
(7) Tilt nose downwards and lower starter motor
far enough to access and remove nut that secures
battery positive cable wire harness connector eyelet
to solenoid battery terminal stud. Do not let starter
motor hang from wire harness.
(8) Remove battery positive cable wire harness
connector eyelet from solenoid battery terminal stud.
(9) Disconnect battery positive cable wire harness
connector from solenoid terminal connector recepta-
cle.
(10) Remove starter motor.
5.7L Gas
(1) Disconnect and isolate negative battery cable.
(2) Raise and support vehicle.
(3) Note: If equipped with 4WD and certain trans-
missions, a support bracket is used between front
axle and side of transmission. Remove 2 support
bracket bolts at transmission. Pry support bracket
slightly to gain access to lower starter mounting bolt.
(4) Remove 2 mounting bolts (Fig. 11).
(5) Move starter motor towards front of vehicle far
enough for nose of starter pinion housing to clear
housing. Always support starter motor during this
process, do not let starter motor hang from wire har-
ness.
(6) Tilt nose downwards and lower starter motor
far enough to access and remove nut that secures
battery positive cable wire harness connector eyelet
to solenoid battery terminal stud. Do not let starter
motor hang from wire harness.
(7) Remove battery positive cable wire harness
connector eyelet from solenoid battery terminal stud.(8) Disconnect battery positive cable wire harness
connector from solenoid terminal connector recepta-
cle.
(9) Remove starter motor.
5.9L Diesel
(1) Disconnect and isolate both negative battery
cables at both batteries.
(2) Raise and support vehicle.
(3) Remove 3 starter mounting bolts (Fig. 12).
Fig. 8 CONTINUITY BETWEEN SOLENOID
TERMINAL AND CASE - TYPICAL
1 - SOLENOID TERMINAL
2 - OHMMETER
3 - SOLENOID
Fig. 9 STARTER R/I - 3.7L/4.7L - MAN. TRANS.
1 - EYELET TERMINAL
2 - NUT
3 - BRACKET
4 - STUD
5 - STARTER MOTOR
6 - LOCK WASHER
7 - WIRE HARNESS CONNECTOR
8 - NUT
9 - SCREW AND WASHER (2)
Fig. 10 STARTER R/I - 3.7L/4.7L - AUTO. TRANS.
1 - EYELET TERMINAL
2 - NUT
3 - SCREW AND WASHER (2)
4 - STARTER MOTOR
5 - WIRE HARNESS CONNECTOR
DRSTARTING 8F - 35
STARTER MOTOR (Continued)

(4) Move starter motor towards front of vehicle far
enough for nose of starter pinion housing to clear
housing. Always support starter motor during this
process. Do not let starter motor hang from wire har-
ness.
(5) Tilt nose downwards and lower starter motor
far enough to access and remove nuts securing
starter wiring harness to starter (Fig. 13). Do not let
starter motor hang from wire harness.
(6) Remove starter motor from engine. Note: Cer-
tain diesel engines use an aluminum spacer (Fig. 12).
Note position and orientation of spacer before
removal.
5.9L Gas
(1) Disconnect and isolate negative battery cable.
(2) Raise and support vehicle.
(3) Note: If equipped with 4WD and certain trans-
missions, a support bracket is used between front
axle and side of transmission. Remove 2 support
bracket bolts at transmission. Pry support bracket
slightly to gain access to lower starter mounting bolt.
(4) Remove nut and lock washer securing starter
motor to mounting stud (Fig. 14).
(5) While supporting starter motor, remove upper
mounting bolt from starter motor.
(6) If equipped with automatic transmission, slide
cooler tube bracket forward on tubes far enough for
starter motor mounting flange to be removed from
lower mounting stud.
(7) Move starter motor towards front of vehicle far
enough for nose of starter pinion housing to clear
Fig. 11 STARTER R/I - 5.7L
1 - STARTER MOTOR
2 - MOUNTING BOLTS
Fig. 12 STARTER R/I - 5.9L DIESEL
1 - MOUNTING BOLTS (3)
2 - STARTER MOTOR
3 - SPACER (CERTAIN TRANSMISSIONS)
Fig. 13 STARTER ELECTRICAL CONNECTORS -
5.9L DIESEL
1 - STARTER MOTOR
2 - BATTERY CABLE NUT
3 - SOLENOID NUT
4 - HARNESS ASSEMBLY
8F - 36 STARTINGDR
STARTER MOTOR (Continued)

housing. Always support starter motor during this
process, do not let starter motor hang from wire har-
ness.
(8) Tilt nose downwards and lower starter motor
far enough to access and remove nut that secures
battery positive cable wire harness connector eyelet
to solenoid battery terminal stud. Do not let starter
motor hang from wire harness.
(9) Remove battery positive cable wire harness
connector eyelet from solenoid battery terminal stud.
(10) Disconnect battery positive cable wire harness
connector from solenoid terminal connector recepta-
cle.
(11) Remove starter motor.
INSTALLATION
3.7L / 4.7L
(1) Connect solenoid wire to starter motor (snaps
on).
(2) Position battery cable to solenoid stud. Install
and tighten battery cable eyelet nut. Refer to Torque
Specifications. Do not allow starter motor to hang
from wire harness.
(3) Position starter motor to transmission.
(4) If equipped with automatic transmission, slide
cooler tube bracket into position.(5) Install and tighten both bolts (auto. trans.), or
1 nut and 1 bolt (man. trans.). Refer to Torque Spec-
ifications.
(6) Lower vehicle.
(7) Connect negative battery cable.
5.7L
(1) Connect solenoid wire to starter motor (snaps
on).
(2) Position battery cable to solenoid stud. Install
and tighten battery cable eyelet nut. Refer to Torque
Specifications. Do not allow starter motor to hang
from wire harness.
(3) Position starter motor to engine.
(4) If equipped with automatic transmission, slide
cooler tube bracket into position.
(5) Install and tighten both mounting bolts. Refer
to Torque Specifications.
(6) Lower vehicle.
(7) Connect negative battery cable.
5.9L Diesel
(1)If Equipped:Position and hold aluminum
spacer to rear of starter while positioning starter to
engine.
(2) Connect solenoid wire to starter motor. Tighten
nut.
(3) Position battery cable to starter stud. Install
and tighten battery cable nut. Refer to Torque Spec-
ifications. Do not allow starter motor to hang from
wire harness.
(4) Position starter motor to transmission.
(5) If equipped with automatic transmission, slide
cooler tube bracket into position.
(6) Install and tighten 3 starter mounting bolts.
Refer to Torque Specifications.
(7) Lower vehicle.
(8) Connect both negative battery cables to both
batteries.
5.9L Gas
(1) Connect solenoid wire to starter motor (snaps
on).
(2) Position battery cable to solenoid stud. Install
and tighten battery cable eyelet nut. Refer to Torque
Specifications. Do not allow starter motor to hang
from wire harness.
(3) Position starter motor to transmission.
(4) If equipped with automatic transmission, slide
cooler tube bracket into position.
(5) Install and tighten both bolts (auto. trans.), or
1 nut and 1 bolt (man. trans.). Refer to Torque Spec-
ifications.
(6) Lower vehicle.
(7) Connect negative battery cable.
Fig. 14 STARTER R/I - 5.9L GAS
1 - ENGINE
2 - STARTER MOUNTING FLANGE
3 - STUD
4 - STARTER MOTOR
5 - LOCK WASHER
6 - NUT
7 - BRACKET
8 - BOLT
9 - POSITIVE BATTERY CABLE WIRE HARNESS
10 - POSITIVE BATTERY CABLE WIRE HARNESS NUT
DRSTARTING 8F - 37
STARTER MOTOR (Continued)