2001 DODGE RAM intake

ket has swollen and prevents vent valve from open-
ing, replace cap.
Hold cap at eye level, upside down. If any light can
be seen between vent valve and rubber gasket,
replace cap.Do not use a replacement cap that
has a spring to hold vent shut.A replacement cap
must be the type designed for a coolant reserve/over-
flow system with a completely sealed diaphragm
spring and a rubber gasket. This gasket is used to
seal to radiator filler neck top surface. Use of proper
cap will allow coolant return to radiator.
WATER PUMP - 3.9L/5.2L/5.9L
DESCRIPTION
The water pump is located on the engine front
cover, and has an integral pulley attached (Fig. 46).
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 by
antifreeze in the coolant mixture. Additional lubrica-
tion is not necessary.
OPERATION
A centrifugal water pump circulates coolant
through the water jackets, passages, intake manifold,
radiator core, cooling system hoses and heater core,
this coolant absorbs the heat generated when the
engine is running. The pump is driven by the engine
crankshaft via a 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
The water pump on all models can be removed
without discharging the air conditioning system (if
equipped).
The water pump on all gas powered engines is
bolted directly to the engine timing chain case/cover.
On all 3.9L/5.2L/5.9L gas powered engines, a gas-
ket is used as a seal between the water pump and
timing chain case/cover.
If water pump is replaced because of bearing/shaft
damage or leaking shaft seal, the mechanical cooling
fan assembly should also be inspected. Inspect for
fatigue cracks, loose blades or loose rivets that could
have resulted from excessive vibration. Replace fan if
any of these conditions are found. Also check condi-
tion of the thermal viscous fan drive (Refer to 7 -
COOLING/ENGINE/FAN DRIVE VISCOUS
CLUTCH - DIAGNOSIS AND TESTING).
(1) Disconnect negative cable from battery.
(2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
Do not waste reusable coolant. If solution is clean,
drain coolant into a clean container for reuse.
(3) Remove windshield washer reservoir tank from
radiator fan shroud.
Fig. 45 Radiator Pressure Cap
1 - STAINLESS-STEEL SWIVEL TOP
2 - RUBBER SEALS
3 - VENT VALVE
4 - RADIATOR TANK
5 - FILLER NECK
6 - OVERFLOW NIPPLE
7 - MAIN SPRING
8 - GASKET RETAINER
Fig. 46 Water Pump LocationÐTypical
1 - WATER PUMP BYPASS HOSE
2 - FAN BLADE ASSEMBLY
3 - VISCOUS FAN DRIVE
4 - WATER PUMP AND PULLEY
BR/BEENGINE 7 - 67
RADIATOR PRESSURE CAP (Continued)

(2) Do not waste reusable coolant. If the solution is
clean, drain the coolant into a clean container for
reuse.
(3) Remove upper radiator hose clamp at radiator.
A special clamp tool must be used to remove the con-
stant tension clamps. Remove hose at radiator.
(4) Disconnect throttle cable from clip at radiator
fan shroud.
(5) Unplug wiring harness from A/C compressor.
(6) Remove the air cleaner assembly.
(7) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(8)3.9L V-6 or 5.2/5.9L V-8 LDC-Gas:The drive
belt idler pulley must be removed to gain access to
one of the A/C compressor/generator bracket mount-
ing bolts. Remove the idler pulley bolt and remove
idler pulley (Fig. 64).
(9)5.9L HDC-Gas:The automatic belt tensioner/
pulley assembly must be removed to gain access to
one of the A/C compressor/generator bracket mount-
ing bolts. Remove the tensioner mounting bolt (Fig.
65) and remove tensioner.(10) Remove the engine oil dipstick tube mounting
bolt at the side of the A/C-generator mounting
bracket.
(11) Disconnect throttle body control cables.
(12) Remove heater hose coolant return tube
mounting bolt (Fig. 66) (Fig. 67) and remove tube
from engine. Discard the old tube O-ring.
(13) Remove bracket-to-intake manifold bolts
(number 1 and 2 (Fig. 63).
(14) Remove remaining bracket-to-engine bolts
(Fig. 68) (Fig. 69).
(15) Lift and position generator and A/C compres-
sor (along with their common mounting bracket) to
gain access to bypass hose. A block of wood may be
used to hold assembly in position.
(16) Loosen and position both hose clamps to the
center of bypass hose. A special clamp tool must be
used to remove the constant tension clamps. Remove
hose from vehicle.
Fig. 64 Idler PulleyÐ3.9L V-6 or 5.2/5.9L V-8
LDC-Gas Engines
Fig. 65 Belt TensionerÐ5.9L HDC-Gas Engine
1 - PULLEY BOLT
2 - IDLER PULLEY
3 - TENSIONER PULLEY
4 - TENSIONER
5 - TENSIONER MOUNTING BOLT
BR/BEENGINE 7 - 75
WATER PUMP INLET TUBE - 3.9L/5.2L/5.9L (Continued)

REMOVALÐWATER PUMP BYPASS HOSE
WITHOUT AIR CONDITIONING
A water pump bypass hose (Fig. 70) is used
between the intake manifold and water pump on all
gas powered engines. To test for leaks, refer to Test-
ing Cooling System for Leaks in this group.
(1) Partially drain cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE). Do not
waste reusable coolant. If the solution is clean, drain
the coolant into a clean container for reuse.
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094). SNAP-ON CLAMP TOOL (NUMBER HPC-20)
MAY BE USED FOR LARGER CLAMPS. ALWAYS
WEAR SAFETY GLASSES WHEN SERVICING CON-
STANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps. If replacement
is necessary, use only an original equipment clamp
with a matching number or letter.
(2) Loosen both bypass hose clamps and position to
the center of hose.
(3) Remove hose from vehicle.
INSTALLATIONÐWATER PUMP BYPASS HOSE
WITH AIR CONDITIONING
(1) Position bypass hose clamps to the center of
hose.
(2) Install bypass hose to engine.
(3) Secure both hose clamps.
(4) Install generator-A/C mounting bracket assem-
bly to engine. Tighten bolt number 1 (Fig. 63) to 41
N´m (30 ft. lbs.) torque. Tighten bolt number 2 (Fig.
63) to 28 N´m (20 ft. lbs.) torque. Tighten bracket
mounting bolts (Fig. 68) (Fig. 69) to 40 N´m (30 ft.
lbs.) torque.
(5) Install a new O-ring to the heater hose coolant
return tube (Fig. 66) (Fig. 67). Coat the new O-ring
with antifreeze before installation.
(6) Install coolant return tube and its mounting
bolt to engine (Fig. 66) (Fig. 67).
(7) Connect throttle body control cables.
(8) Install oil dipstick mounting bolt.
(9)3.9L V-6 or 5.2/5.9L V-8 LDC-Gas Engines:
Install idler pulley. Tighten bolt to 41 N´m (30 ft.
lbs.) torque.
(10)5.9L HDC-Gas:Install automatic belt ten-
sioner assembly to mounting bracket. A dowel pin is
located on back of tensioner (Fig. 71). Align this to
dowel hole (Fig. 72) in tensioner mounting bracket.
Tighten bolt to 41 N´m (30 ft. lbs.) torque.
(11) Install drive belt (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - INSTALLA-
TION).
Fig. 71 Tensioner Dowel PinÐ5.9L HDC-Gas Engine
1 - BELT TENSIONER
2 - DOWEL PIN
Fig. 70 Water Pump Bypass HoseÐTypical
1 - WATER PUMP BYPASS HOSE
2 - FAN BLADE ASSEMBLY
3 - VISCOUS FAN DRIVE
4 - WATER PUMP AND PULLEY
BR/BEENGINE 7 - 77
WATER PUMP INLET TUBE - 3.9L/5.2L/5.9L (Continued)

(9) Re-install the thermostat cover onto the oil
cooler and install the snap-ring.
(10) Re-connect the oil cooler to the transmission
cooler lines.
(11) Turn pump ON for two to three minutes to
flush cooler(s) and lines.
NOTE: This flushes the bypass circuit of the cooler
only.
(12) Turn pump OFF.
(13) Remove the thermostat cover from the oil
cooler.
(14) Install Special Tool Cooler Plug 8414 into the
transmission oil cooler.
(15) Re-install the thermostat cover onto the oil
cooler and install the snap-ring.
(16) Turn pump ON for two to three minutes to
flush cooler(s) and lines.
NOTE: This flushes the main oil cooler core pas-
sages only.
(17) Turn pump OFF.
(18) Remove the thermostat cover from the oil
cooler.
(19) Remove Special Tool Cooler Plug 8414 from
the transmission oil cooler.
(20) Install a new thermostat spring, thermostat,
cover, and snap-ring into the transmission oil cooler.
(Refer to 7 - COOLING/TRANSMISSION/TRANS
COOLER - ASSEMBLY)
(21) Install the transmission oil cooler onto the
vehicle. (Refer to 7 - COOLING/TRANSMISSION/
TRANS COOLER - INSTALLATION)
(22) Disconnect CLEAR suction line from reservoir
at cover plate. Disconnect CLEAR return line at
cover plate, and place it in a drain pan.
(23) Turn pump ON for 30 seconds to purge flush-
ing solution from cooler and lines. Turn pump OFF.
(24) Place CLEAR suction line into a one quart
container of MopartATF +4, type 9602, Automatic
Transmission fluid.
(25) Turn pump ON until all transmission fluid is
removed from the one quart container and lines. This
purges any residual cleaning solvent from the trans-
mission cooler and lines. Turn pump OFF.
(26) Disconnect alligator clips from battery. Recon-
nect flusher lines to cover plate, and remove flushing
adapters from cooler lines.
REMOVALÐAIR TO OIL COOLER
(1) Remove front bumper.
(2) Place a drain pan under the oil cooler.
(3) Raise the vehicle.
(4) Disconnect the oil cooler quick-connect fittings
from the transmission lines.(5) Remove the charge air cooler-to-oil cooler bolt
(Fig. 8).
(6) Remove two mounting nuts.
(7) Remove the oil cooler and line assembly
towards the front of vehicle. Cooler must be rotated
and tilted into position while removing.
REMOVALÐWATER TO OIL COOLER
CAUTION: If a leak should occur in the water-to-oil
cooler mounted to the side of the engine block,
engine coolant may become mixed with transmis-
sion fluid. Transmission fluid may also enter engine
cooling system. Both cooling system and transmis-
sion should be drained and inspected in case of oil
cooler leakage.
(1) Disconnect both battery negative cables.
(2) Remove air cleaner assembly and air cleaner
intake hoses.
(3) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(4) Disconnect coolant lines from cooler.
(5) Disconnect transmission oil lines from cooler.
Plug cooler lines to prevent oil leakage.
(6) Remove oil cooler mounting straps (Fig. 9).
Fig. 8 Auxiliary Transmission Oil CoolerÐDiesel
Engine
1 - CHARGE AIR COOLER (INTERCOOLER)
2 - QUICK-CONNECT FITTINGS (2)
3 - MOUNTING NUTS (2)
4 - MOUNTING BOLT
5 - TRANSMISSION OIL COOLER
BR/BETRANSMISSION 7 - 87
TRANS COOLER - 5.9L DIESEL (Continued)

(7) Lift oil cooler off of mounting bracket.
(8) If replacing cooler, make sure to transfer con-
verter drain back valve to new cooler.INSTALLATIONÐAIR TO OIL COOLER
(1) Carefully position the oil cooler assembly to the
vehicle.
(2) Install two nuts and one bolt. Tighten to 11
N´m (95 in. lbs.) torque.
(3) Connect the quick-connect fittings to the trans-
mission cooler lines.
(4) Install front bumper.
(5) Start the engine and check all fittings for
leaks.
(6) Check the fluid level in the automatic trans-
mission (Refer to 21 - TRANSMISSION/TRAN-
SAXLE/AUTOMATIC - 47RE/FLUID - STANDARD
PROCEDURE).
INSTALLATION
(1) Position oil cooler on bracket.
(2) Install mounting straps.
(3) Connect transmission oil lines to cooler.
(4) Connect coolant hoses to cooler.
(5) Connect battery negative cables.
(6) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(7) Check transmission oil level and fill as neces-
sary (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 47RE/FLUID - STANDARD
PROCEDURE).
(8) Install air cleaner assembly and air cleaner
intake hoses.
Fig. 9 Transmission Water-To- Oil CoolerÐDiesel
1 - TRANSMISSION WATER-TO-OIL COOLER
7 - 88 TRANSMISSIONBR/BE
TRANS COOLER - 5.9L DIESEL (Continued)

ENGINE CONTROL MODULE
DESCRIPTION - ECM
The ECM is bolted to the left side of the engine
behind the fuel filter (Fig. 14). It is a separate com-
ponent and can be serviced. The FPCM is internal to
the fuel injection pump (Fig. 15) and cannot be ser-
viced.
OPERATION - ECM
The main functions of the Engine Control Module
(ECM) and Fuel Injection Pump Control Module
(FPCM) are to electrically control the fuel system.
The Powertrain Control Module (PCM)does not
controlthe 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
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
²(FPCM) Fuel Injection Pump Control Module
²Engine Coolant Temperature (ECT) sensor
²Ground circuits
²Intake manifold Air Temperature (IAT) sensor
²Manifold Air Pressure Sensor (Boost Pressure
Sensor)
²Oil pressure sensor
²PCM
²Power Take Off (PTO)
²Power ground
²Sensor return
²Signal ground
²Water-In-Fuel (WIF) sensor
Fig. 14 Engine Control Module (ECM) Location
1 - ENGINE CONTROL MODULE (ECM)
2 - HEX HEADED BOLT
3 - 50-WAY CONNECTOR
4 - FUEL TRANSFER PUMP
5 - MOUNTING BOLTS (3)
Fig. 15 Fuel Injection Pump Control Module (FPCM)
Location
1 - FPCM ELECTRICAL CONNECTOR
2 - HIGH-PRESSURE FUEL LINES
3 - FITTINGS
4 - FUEL INJECTION PUMP
5 - FPCM
BR/BEELECTRONIC CONTROL MODULES 8E - 13

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 injection pump
²Fuel injection pump relay
²(FPCM) Fuel Pump Control Module
²Fuel transfer (lift) pump
²Intake manifold air heater relays #1 and #2 con-
trol circuits
²Malfunction indicator lamp (Check engine lamp)
²Oil pressure gauge/warning lamp
²PCM
²Wait-to-start warning lamp
²Water-In-Fuel (WIF) warning lamp
REMOVAL
The ECM is bolted to the engine block behind the
fuel filter (Fig. 16).
(1) Record any Diagnostic Trouble Codes (DTC's)
found in the PCM or ECM.To avoid possible voltage spike damage to either
the Powertrain Control Module (PCM) or ECM, igni-
tion key must be off, and negative battery cables
must be disconnected before unplugging ECM con-
nectors.
(2) Disconnect both negative battery cables at both
batteries.
(3) Remove 50±way electrical connector bolt at
ECM (Fig. 16). Note: Connector bolt is female 4mm
hex head. To remove bolt, use a ball-hex bit or ball-
hex screwdriver such as Snap-Ont4mm SDABM4
(5/32º may also be used). As bolt is being removed,
very carefully remove connector from ECM.
(4) Remove three ECM mounting bolts and remove
ECM from vehicle.
INSTALLATION
Do not apply paint to back of ECM. Poor ground
will result.
(1) Clean ECM mounting points at engine block.
(2) Position ECM to engine block and install 3
mounting bolts. Tighten bolts to 24 N´m (18 ft. lbs.).
(3) Check pin connectors in ECM and 50±way con-
nector for corrosion or damage. Repair as necessary.
(4) Clean pins in 50±way electrical connector with
a quick-dry electrical contact cleaner.
(5) Very carefully install 50±way connector to
ECM. Tighten connector hex bolt.
(6) Install battery cables.
(7)Turn key to ON position. Without starting
engine, slowly press throttle pedal to floor and
then slowly release. This step must be done
(one time) to ensure accelerator pedal position
sensor calibration has been learned by ECM. If
not done, possible DTC's may be set.
(8) Use DRB scan tool to erase any stored compan-
ion DTC's from PCM.
POWERTRAIN CONTROL
MODULE
DESCRIPTION - PCM
The Powertrain Control Module (PCM) is located
in the engine compartment (Fig. 17). The PCM is
referred to as JTEC.
DESCRIPTION - MODES OF OPERATION
As input signals to the Powertrain Control Module
(PCM) change, the PCM adjusts its response to the
output devices. For example, the PCM must calculate
different injector pulse width and ignition timing for
idle than it does for wide open throttle (WOT).
The PCM will operate in two different modes:
Open Loop and Closed Loop.
Fig. 16 Engine Control Module (ECM) Location and
Mounting
1 - ENGINE CONTROL MODULE (ECM)
2 - HEX HEADED BOLT
3 - 50-WAY CONNECTOR
4 - FUEL TRANSFER PUMP
5 - MOUNTING BOLTS (3)
8E - 14 ELECTRONIC CONTROL MODULESBR/BE
ENGINE CONTROL MODULE (Continued)

During Open Loop modes, the PCM receives input
signals and responds only according to preset PCM
programming. Input from the oxygen (O2S) sensors
is not monitored during Open Loop modes.
During Closed Loop modes, the PCM will monitor
the oxygen (O2S) sensors input. This input indicates
to the PCM whether or not the calculated injector
pulse width results in the ideal air-fuel ratio. This
ratio is 14.7 parts air-to-1 part fuel. By monitoring
the exhaust oxygen content through the O2S sensor,
the PCM can fine tune the injector pulse width. This
is done to achieve optimum fuel economy combined
with low emission engine performance.
The fuel injection system has the following modes
of operation:
²Ignition switch ON
²Engine start-up (crank)
²Engine warm-up
²Idle
²Cruise
²Acceleration
²Deceleration
²Wide open throttle (WOT)
²Ignition switch OFF
The ignition switch On, engine start-up (crank),
engine warm-up, acceleration, deceleration and wide
open throttle modes are Open Loop modes. The idle
and cruise modes, (with the engine at operating tem-
perature) are Closed Loop modes.
IGNITION SWITCH (KEY-ON) MODE
This is an Open Loop mode. When the fuel system
is activated by the ignition switch, the following
actions occur:²The PCM pre-positions the idle air control (IAC)
motor.
²The PCM determines atmospheric air pressure
from the MAP sensor input to determine basic fuel
strategy.
²The PCM monitors the engine coolant tempera-
ture sensor input. The PCM modifies fuel strategy
based on this input.
²Intake manifold air temperature sensor input is
monitored.
²Throttle position sensor (TPS) is monitored.
²The auto shutdown (ASD) relay is energized by
the PCM for approximately three seconds.
²The fuel pump is energized through the fuel
pump relay by the PCM. The fuel pump will operate
for approximately three seconds unless the engine is
operating or the starter motor is engaged.
²The O2S sensor heater element is energized via
the ASD relay. The O2S sensor input is not used by
the PCM to calibrate air-fuel ratio during this mode
of operation.
ENGINE START-UP MODE
This is an Open Loop mode. The following actions
occur when the starter motor is engaged.
The PCM receives inputs from:
²Battery voltage
²Engine coolant temperature sensor
²Crankshaft position sensor
²Intake manifold air temperature sensor
²Manifold absolute pressure (MAP) sensor
²Throttle position sensor (TPS)
²Starter motor relay
²Camshaft position sensor signal
The PCM monitors the crankshaft position sensor.
If the PCM does not receive a crankshaft position
sensor signal within 3 seconds of cranking the
engine, it will shut down the fuel injection system.
The fuel pump is activated by the PCM through
the fuel pump relay.
Voltage 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 determines the proper ignition timing
according to input received from the crankshaft posi-
tion sensor.
ENGINE WARM-UP MODE
This is an Open Loop mode. During engine warm-
up, the PCM receives inputs from:
²Battery voltage
²Crankshaft position sensor
²Engine coolant temperature sensor
²Intake manifold air temperature sensor
Fig. 17 PCM Location
1 - PCM MOUNTING BOLTS (3)
2 - POWERTRAIN CONTROL MODULE (PCM)
3 - (3) 32±WAY CONNECTORS
BR/BEELECTRONIC CONTROL MODULES 8E - 15
POWERTRAIN CONTROL MODULE (Continued)