2003 DODGE RAM POWER STEERING PUMP

(5) Remove pulley bolt. Remove pulley from ten-
sioner.
INSTALLATION
(1) Install pulley and pulley bolt to tensioner.
Tighten bolt to 61 N´m (45 ft. lbs.) torque.
(2) Install tensioner assembly to mounting
bracket. An indexing tab is located on back of ten-
sioner. Align this tab to slot in mounting bracket.
Tighten nut to 67 N´m (50 ft. lbs.) torque.
(3) Connect all wiring to ignition coil.
CAUTION: To prevent damage to coil case, coil
mounting bolts must be torqued.
(4) Install coil to coil bracket. If nuts and bolts are
used to secure coil to coil bracket, tighten to 11 N´m
(100 in. lbs.) torque. If coil mounting bracket has
been tapped for coil mounting bolts, tighten bolts to 5
N´m (50 in. lbs.) torque.
(5) Install drive belt. (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - INSTALLA-
TION).
(6) Check belt indexing marks (Fig. 4).
BELT TENSIONERS - 5.9L
DIESEL
DESCRIPTION
Drive belts on all engines are equipped with a
spring loaded automatic belt tensioner (Fig. 5). This
tensioner maintains constant belt tension at all times
and requires no maintenance or adjustment.
CAUTION: Do not attempt to check belt tension with
a belt tension gauge on vehicles equipped with an
automatic belt tensioner.
OPERATION
WARNING: THE AUTOMATIC BELT TENSIONER
ASSEMBLY IS SPRING LOADED. DO NOT ATTEMPT
TO DISASSEMBLE THE TENSIONER ASSEMBLY.
The automatic belt tensioner maintains correct belt
tension using a coiled spring within the tensioner
housing. The spring applies pressure to the tensioner
arm pressing the arm into the belt, tensioning the
belt.
Fig. 4 Tensioner Indexing Marks And Mounting Nut
1 - TENSIONER ASSEMBLY
2 - TENSIONER MOUNTING NUT
3 - INDEXING ARROW
4 - INDEXING MARK
Fig. 5 Belt
1 - GENERATOR
2 - WATER PUMP
3 - IDLER
4 - POWER STEERING PUMP
5 - AUTOMATIC TENSIONER
6 - A/C COMPRESSOR
7 - 24 ACCESSORY DRIVEDR
BELT TENSIONERS - 5.9L (Continued)

REMOVAL
WARNING: BECAUSE OF HIGH SPRING PRES-
SURE, DO NOT ATTEMPT TO DISASSEMBLE AUTO-
MATIC TENSIONER. UNIT IS SERVICED AS AN
ASSEMBLY.
(1) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(2) Remove tensioner mounting bolt (Fig. 6) and
remove tensioner.
INSTALLATION
(1) Install tensioner assembly to mounting
bracket. A dowel is located on back of tensioner. Align
this dowel to hole in tensioner mounting bracket.
Tighten bolt to 43 N´m (32 ft. lbs.) torque.
(2) Install drive belt (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - INSTALLA-
TION).
DRIVE BELTS - 3.7L / 4.7L
DIAGNOSIS AND TESTING - ACCESSORY
DRIVE BELT
VISUAL DIAGNOSIS
When diagnosing serpentine accessory drive belts,
small cracks that run across the ribbed surface of the
belt from rib to rib (Fig. 7), are considered normal.
These are not a reason to replace the belt. However,
cracks running along a rib (not across) arenotnor-
mal. Any belt with cracks running along a rib must
be replaced (Fig. 7). Also replace the belt if it has
excessive wear, frayed cords or severe glazing.
Refer to ACCESSORY DRIVE BELT DIAGNOSIS
CHART for further belt diagnosis.
NOISE DIAGNOSIS
Noises generated by the accessory drive belt are
most noticeable at idle. Before replacing a belt to
resolve a noise condition, inspect all of the accessory
drive pulleys for alignment, glazing, or excessive end
play.
Fig. 6 AUTOMATIC BELT TENSIONER DIESEL
ENGINE-TYPICAL
1 - GENERATOR
2 - WATER PUMP
3 - IDLER
4 - POWER STEERING PUMP
5 - AUTOMATIC TENSIONER
6 - A/C COMPRESSOR
Fig. 7 Belt Wear Patterns
1 - NORMAL CRACKS BELT OK
2 - NOT NORMAL CRACKS REPLACE BELT
DRACCESSORY DRIVE 7 - 25
BELT TENSIONERS - 5.9L DIESEL (Continued)

DRIVE BELTS - 5.9L
DIAGNOSIS AND TESTING - ACCESSORY
DRIVE BELT
VISUAL DIAGNOSIS
When diagnosing serpentine accessory drive belts,
small cracks that run across the ribbed surface of the
belt from rib to rib (Fig. 10), are considered normal.
These are not a reason to replace the belt. However,
cracks running along a rib (not across) arenotnor-
mal. Any belt with cracks running along a rib must
be replaced (Fig. 10). Also replace the belt if it has
excessive wear, frayed cords or severe glazing.
Refer to ACCESSORY DRIVE BELT DIAGNOSIS
CHART for further belt diagnosis.
NOISE DIAGNOSIS
Noises generated by the accessory drive belt are
most noticeable at idle. Before replacing a belt to
resolve a noise condition, inspect all of the accessory
drive pulleys for alignment, glazing, or excessive end
play.
Fig. 8 BELT ROUTING 3.7L / 4.7L
1 - GENERATOR PULLEY
2 - ACCESSORY DRIVE BELT
3 - POWER STEERING PUMP PULLEY
4 - CRANKSHAFT PULLEY
5 - IDLER PULLEY
6 - TENSIONER
7 - A/C COMPRESSOR PULLEY
8 - WATER PUMP PULLEY
Fig. 9 Accessory Drive Belt Wear Indicator±4.7L
Engine
1 - AUTOMATIC TENSIONER ASSEMBLY
Fig. 10 Belt Wear Patterns
1 - NORMAL CRACKS BELT OK
2 - NOT NORMAL CRACKS REPLACE BELT
7 - 28 ACCESSORY DRIVEDR
DRIVE BELTS - 3.7L / 4.7L (Continued)

INSTALLATION
CAUTION: When installing the accessory drive belt,
the belt must be routed correctly. If not, engine may
overheat due to water pump rotating in wrong
direction. Refer to (Fig. 12) (Fig. 13) for correct
engine belt routing. The correct belt with correct
length must be used.
(1) Position drive belt over all pulleysexceptidler
pulley. This pulley is located between generator and
A/C compressor.
(2) Attach a socket/wrench to pulley mounting bolt
of automatic tensioner (Fig. 11).
(3) Rotate socket/wrench clockwise. Place belt over
idler pulley. Let tensioner rotate back into place.
Remove wrench. Be sure belt is properly seated on
all pulleys.
(4) Check belt indexing marks (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/BELT TENSIONERS -
DESCRIPTION).
DRIVE BELTS - 5.9L DIESEL
DIAGNOSIS AND TESTINGÐACCESSORY
DRIVE BELT
VISUAL DIAGNOSIS
When diagnosing serpentine accessory drive belts,
small cracks that run across the ribbed surface of the
belt from rib to rib (Fig. 14), are considered normal.
These are not a reason to replace the belt. However,
cracks running along a rib (not across) arenotnor-
mal. Any belt with cracks running along a rib must
be replaced (Fig. 14). Also replace the belt if it has
excessive wear, frayed cords or severe glazing.
Fig. 12 Belt Routing - 5.9L Engines with A/C
1 - GENERATOR PULLEY
2 - A/C PULLEY
3 - POWER STEERING PULLEY
4 - CRANKSHAFT PULLEY
5 - WATER PUMP PULLEY
6 - TENSIONER PULLEY
7 - IDLER PULLEY
Fig. 13 Belt Routing - 5.9L Engines Without A/C
1 - GENERATOR PULLEY
2 - IDLER PULLEY
3 - POWER STEERING PULLEY
4 - CRANKSHAFT PULLEY
5 - WATER PUMP PULLEY
6 - TENSIONER PULLEY
DRACCESSORY DRIVE 7 - 31
DRIVE BELTS - 5.9L (Continued)

NOTE: The engine speed sensor face is very close
to the accessory drive belt. Inspect engine speed
sensor and wire harness for damage when acces-
sory drive belt has been replaced due to failure or
abnormal conditions.
REMOVAL
CAUTION: Do not attempt to check belt tension with
a belt tension gauge on vehicles equipped with an
automatic belt tensioner. Refer to Automatic Belt
Tensioner in this group.
NOTE: The belt routing schematics are published
from the latest information available at the time of
publication. If anything differs between these sche-
matics and the Belt Routing Label, use the sche-
matics on Belt Routing Label.This label is located in
the engine compartment.
Drive belts on diesel engines are equipped with a
spring loaded automatic belt tensioner.displays the
tensioner for vehicles without air conditioning.
This belt tensioner will be used on all belt config-
urations, such as with or without air conditioning.
For more information, (Refer to 7 - COOLING/AC-
CESSORY DRIVE/BELT TENSIONERS - DESCRIP-
TION).
(1) A 1/2 inch square hole is provided in the auto-
matic belt tensioner. Attach a 1/2 inch drive-long
handle ratchet to this hole.
(2) Rotate ratchet and tensioner assembly clock-
wise (as viewed from front) until tension has been
relieved from belt.
(3) Remove belt from water pump pulley first.
(4) Remove belt from vehicle.
INSTALLATION
CAUTION: When installing the accessory drive belt,
the belt must be routed correctly. If not, engine mayoverheat due to water pump rotating in wrong
direction. Refer to (Fig. 15) for correct engine belt
routing. The correct belt with correct length must
be used.
(1) Position drive belt over all pulleysexcept
water pump pulley.
(2) Attach a 1/2 inch ratchet to tensioner.
(3) Rotate ratchet and belt tensioner clockwise.
Place belt over water pump pulley. Let tensioner
rotate back into place. Remove ratchet. Be sure belt
is properly seated on all pulleys.
Fig. 15 Belt Routing±5.9L Diesel Engine
1 - GENERATOR PULLEY
2 - WATER PUMP PULLEY
3 - IDLER PULLEY
4 - POWER STEERING PUMP PULLEY
5 - RADIATOR FAN PULLEY
6 - CRANKSHAFT PULLEY
7 - AUTOMATIC TENSIONER
8 - A/C COMPRESSOR PUMP PULLEY
7 - 34 ACCESSORY DRIVEDR
DRIVE BELTS - 5.9L DIESEL (Continued)

(6) Install the radiator upper hose to the thermo-
stat housing.
CAUTION: When installing the serpentine accessory
drive belt, the belt must be routed correctly. If not,
the engine may overheat due to the water pump
rotating in wrong direction. Refer to (Fig. 24) for the
correct 5.9L engine belt routing. The correct belt
with correct length must be used.
(7) Air Conditioned vehicles; Install the generator.
Tighten the bolts to 41 N´m (30 ft. lbs.).
(8) Install the support bracket (generator mount-
ing bracket-to-intake manifold). (Fig. 19). Tighten the
bolts to 54 N´m (40 ft. lbs.).
(9) Install the accessory drive belt (Fig. 20)(Refer
to 7 - COOLING/ACCESSORY DRIVE/DRIVE
BELTS - INSTALLATION).
(10) Fill the cooling system (Refer to 7 - COOLING
- STANDARD PROCEDURE).
(11) Connect battery negative cable.
(12) Start and warm the engine. Check for leaks.
ENGINE COOLANT
THERMOSTAT - 3.7L/4.7L
DESCRIPTION
CAUTION: Do not operate the engine without a ther-
mostat, except for servicing or testing.
A pellet-type thermostat controls the operating
temperature of the engine by controlling the amount
of coolant flow to the radiator. On all engines the
thermostat is closed below 195ÉF (90ÉC). Above this
temperature, coolant is allowed to flow to the radia-
tor. This provides quick engine warm up and overall
temperature control. On the 3.7L4.7L engine the
thermostat is designed to block the flow of the cool-
ant bypass journal by 50% instead of completely
blocking the flow. This design controls coolant tem-
perature more accurately (Fig. 25).
The same thermostat is used for winter and sum-
mer seasons. An engine should not be operated with-
out a thermostat, except for servicing or testing.
Operating without a thermostat causes other prob-
lems. These are: longer engine warmup time, unreli-
able warmup performance, increased exhaust
Fig. 23 Thermostat PositionÐ5.9L EnginesFig. 24 Belt Routing ± 5.9L Engines
1 - IDLER PULLEY
2 - GENERATOR PULLEY
3 - A/C COMPRESSOR PULLEY
4 - IF W/OUT A/C
5 - POWER STEERING PUMP PULLEY
6 - WATER PUMP PULLEY
7 - CRANKSHAFT PULLEY
8 - AUTOMATIC TENSIONER
7 - 50 ENGINEDR
ENGINE COOLANT THERMOSTAT- 5.7L/5.9L (Continued)

CAUTION: When installing the serpentine accessory
drive belt, the belt must be routed correctly. If not,
the engine may overheat due to the water pump
rotating in the wrong direction. Refer to (Fig. 49) for
the correct belt routing. Or, refer to the Belt Routing
Label located in the engine compartment. The cor-
rect belt with correct length must be used.
(6) Install the radiator fan (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - INSTALLATION).
(7) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(8) Connect the negative battery cable.
(9) Start and warm the engine. Check for leaks.
WATER PUMP - 5.9L DIESEL
DESCRIPTION
The water pump is mounted to the front of the
engine block between the automatic belt tensioner
and the fan drive pulley.
The water pump impeller is pressed onto the rear
of a shaft that rotates in a bearing pressed into the
water pump body. The body has a small hole for ven-
tilation. The water pump seals are lubricated byantifreeze in the coolant mixture. Additional lubrica-
tion is not necessary.
OPERATION
The diesel engine water pump draws coolant from
radiator outlet and circulates it through engine,
heater core and back to radiator inlet. The crank-
shaft pulley drives the water pump with a serpentine
drive belt.
DIAGNOSIS AND TESTINGÐWATER PUMP
A quick test to determine if pump is working is to
check if heater warms properly. A defective water
pump will not be able to circulate heated coolant
through the long heater hose to the heater core.
REMOVAL
(1) Disconnect battery negative cables.
(2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(4) Remove water pump mounting bolts (Fig. 50).
(5) Clean water pump sealing surface on cylinder
block.
CLEANING
Clean gasket mating surfaces as necessary.
Fig. 49 Belt Routing 3.7L
1 - GENERATOR PULLEY
2 - ACCESSORY DRIVE BELT
3 - POWER STEERING PUMP PULLEY
4 - CRANKSHAFT PULLEY
5 - IDLER PULLEY
6 - TENSIONER
7 - A/C COMPRESSOR PULLEY
8 - WATER PUMP PULLEY
Fig. 50 Water Pump Removal/Installation
1 - O-RING SEAL (SQUARE)
2 - WATER PUMP
3 - BOLT (2)
DRENGINE 7 - 67
WATER PUMP - 3.7L/4.7L (Continued)

²Cyclic Redundancy Check (CRC) Byte- This
byte is used to detect errors during a message trans-
mission.
²In-Frame Response (IFR) byte(s)-Ifa
response is required from the target module(s), it can
be sent during this frame. This function is described
in greater detail in the following paragraph.
The IFR consists of one or more bytes, which are
transmitted during a message. If the sending module
requires information to be received immediately, the
target module(s) can send data over the bus during
the original message. This allows the sending module
to receive time-critical information without having to
wait for the target module to access the bus. After
the IFR is received, the sending module broadcasts
an End of Frame (EOF) message and releases control
of the bus.
The PCI data bus can be monitored using the
DRBIIItscan tool. It is possible, however, for the bus
to pass all DRBIIIttests and still be faulty if the
voltage parameters are all within the specified range
and false messages are being sent.
CONTROLLER ANTILOCK
BRAKE
DESCRIPTION
The Controler Antilock Brake (CAB) is mounted to
the Hydraulic Control Unit (HCU) and operates the
ABS system (Fig. 1).
OPERATION
The CAB voltage source is through the ignition
switch in the RUN position. The CAB contains a self
check program that illuminates the ABS warning
light when a system fault is detected. Faults are
stored in a diagnostic program memory and are
accessible with the DRB III scan tool. ABS faults
remain in memory until cleared, or until after the
vehicle is started approximately 50 times. Stored
faults arenoterased if the battery is disconnected.
NOTE: If the CAB is being replaced with a new CAB
is must be reprogrammed with the use of a DRB III.
REMOVAL
(1) Remove the negative battery cable from the
battery.
(2) Pull up on the CAB harness connector release
and remove connector.
(3) Remove the CAB mounting bolts.
(4) Remove the pump connector from the CAB.
(5) Remove the CAB from the HCU.
INSTALLATION
NOTE: If the CAB is being replaced with a new CAB
is must be reprogrammed with the use of a DRB III.
(1) Install CAB to the HCU.
(2) Install the pump connector to the CAB.
(3) Install mounting bolts. Tighten to 2 N´m (16 in.
lbs.).
(4) Install the wiring harness connector to the
CAB and push down on the release to secure the con-
nector.
(5) Install negative battery cable to the battery.
DATA LINK CONNECTOR
DESCRIPTION - DATA LINK CONNECTOR
The Data Link Connector (DLC) is located at the
lower edge of the instrument panel near the steering
column.
OPERATION - DATA LINK CONNECTOR
The 16±way data link connector (diagnostic scan
tool connector) links the Diagnostic Readout Box
(DRB) scan tool or the Mopar Diagnostic System
(MDS) with the Powertrain Control Module (PCM).
Fig. 1 HYDRAULIC CONTROL UNIT
1 - HYDRAULIC CONTROL UNIT
2 - MOUNTING BOLTS
DRELECTRONIC CONTROL MODULES 8E - 3
COMMUNICATION (Continued)