air conditioning DODGE RAM 2003 Service Owner's Manual

OPERATION
OPERATION - PCM
The PCM operates the fuel system. The PCM is a
pre-programmed, triple microprocessor digital com-
puter. It regulates ignition timing, air-fuel ratio,
emission control devices, charging system, certain
transmission features, speed control, air conditioning
compressor clutch engagement and idle speed. The
PCM can adapt its programming to meet changing
operating conditions.
The PCM receives input signals from various
switches and sensors. Based on these inputs, the
PCM regulates various engine and vehicle operations
through different system components. These compo-
nents are referred to as Powertrain Control Module
(PCM) Outputs. The sensors and switches that pro-
vide inputs to the PCM are considered Powertrain
Control Module (PCM) Inputs.
The PCM adjusts ignition timing based upon
inputs it receives from sensors that react to: engine
rpm, manifold absolute pressure, engine coolant tem-
perature, throttle position, transmission gear selec-
tion (automatic transmission), vehicle speed, power
steering pump pressure, and the brake switch.
The PCM adjusts idle speed based on inputs it
receives from sensors that react to: throttle position,
vehicle speed, transmission gear selection, engine
coolant temperature and from inputs it receives from
the air conditioning clutch switch and brake switch.
Based on inputs that it receives, the PCM adjusts
ignition coil dwell. The PCM also adjusts the gener-
ator charge rate through control of the generator
field and provides speed control operation.
NOTE: PCM Inputs:
²ABS module (if equipped)
²A/C request (if equipped with factory A/C)
²A/C select (if equipped with factory A/C)
²A/C pressure transducer
²Auto shutdown (ASD) sense
²Battery temperature sensor
²Battery voltage
²Brake switch
²J1850 bus (+) circuits
²J1850 bus (-) circuits
²Camshaft position sensor signal
²Crankshaft position sensor
²Data link connection for DRB scan tool
²EATX module (if equipped)
²Engine coolant temperature sensor
²Fuel level (through J1850 circuitry)
²Generator (battery voltage) output
²Ignition circuit sense (ignition switch in on/off/
crank/run position)²Intake manifold air temperature sensor
²Knock sensors (2 on 3.7L engine)
²Leak detection pump (switch) sense (if equipped)
²Manifold absolute pressure (MAP) sensor
²Oil pressure
²Oxygen sensors
²Park/neutral switch (auto. trans. only)
²Power ground
²Power steering pressure switch (if equipped)
²Sensor return
²Signal ground
²Speed control multiplexed single wire input
²Throttle position sensor
²Transfer case switch (4WD range position)
²Vehicle speed signal
NOTE: PCM Outputs:
²A/C clutch relay
²Auto shutdown (ASD) relay
²J1850 bus (+/-) circuits for: speedometer, voltme-
ter, fuel gauge, oil pressure gauge/lamp, engine temp.
gauge and speed control warn. lamp
²Data link connection for DRB scan tool
²EGR valve control solenoid (if equipped)
²EVAP canister purge solenoid
²Five volt sensor supply (primary)
²Five volt sensor supply (secondary)
²Fuel injectors
²Fuel pump relay
²Generator field driver (-)
²Generator field driver (+)
²Idle air control (IAC) motor
²Ignition coil(s)
²Leak detection pump (if equipped)
²Malfunction indicator lamp (Check engine lamp).
Driven through J1850 circuits.
²Oxygen sensor heater relays
²Oxygen sensors (pulse width modulated)
²Radiator cooling fan relay (pulse width modu-
lated)
²Speed control vacuum solenoid
²Speed control vent solenoid
²Tachometer (if equipped). Driven through J1850
circuits.
²Transmission convertor clutch circuit. Driven
through J1850 circuits.
OPERATION - 5 VOLT SUPPLIES
Primary 5±volt supply:
²supplies the required 5 volt power source to the
Crankshaft Position (CKP) sensor.
²supplies the required 5 volt power source to the
Camshaft Position (CMP) sensor.
²supplies a reference voltage for the Manifold
Absolute Pressure (MAP) sensor.
DRELECTRONIC CONTROL MODULES 8E - 11
POWERTRAIN CONTROL MODULE (Continued)

seven integral snap features to the instrument panel
base trim, while two screws secure the integral
inboard mounting flange to the base trim, and four
screws secure the lower mounting flange to the upper
glove box opening reinforcement integral to the
instrument panel structural support. The passenger
airbag door includes two air conditioning panel out-
lets and their housings. Each of the panel outlet
housings feature four snap features that secure them
to the back of the airbag door and two mounting tabs
that are also secured with one screw each to the
upper glove box opening reinforcement.
Located behind the passenger airbag door within
the instrument panel is the passenger airbag unit
(Fig. 31). The passenger airbag housing fits into a
molded receptacle on the back of the airbag door,
where six stamped hook formations on the upper and
lower edges of the airbag housing are engaged in six
small window openings on the upper and lower
flanges of the receptacle to secure the airbag door to
the airbag housing. The inboard airbag door fasten-
ers and mounting flange are concealed beneath the
instrument panel center bezel, while the lower fas-
teners and mounting flange are concealed beneath
the instrument panel lower surround. The passenger
airbag unit is secured by four screws through four
brackets (two front and two rear) that are integral to
the base of the airbag housing to the instrument
panel structural support.
The passenger airbag unit used in this model is a
Next Generation-type that complies with revised fed-
eral airbag standards to deploy with less force thanthose used in some prior models. The passenger air-
bag unit consists of a stamped and welded metal
housing, the airbag cushion, the airbag inflator, and
a stamped metal airbag and inflator retainer plate
that is secured to the airbag housing with six studs
and nuts. The airbag housing contains the airbag
inflator and the folded airbag cushion. An approxi-
mately 80 centimeter (31.5 inch) wide by 90 centime-
ter (35.5 inch) high rectangular fabric cushion is
used. The airbag inflator is a non-azide, pyrotechnic-
type unit that is secured to and sealed within the air-
bag housing. The inflator initiator is connected to the
vehicle electrical system through a dedicated take
out and connector of the instrument panel wire har-
ness.
The passenger airbag includes the airbag door and
the two panel outlet housings. This unit cannot be
repaired, and must be replaced if deployed, faulty, or
in any way damaged.
OPERATION
The passenger airbag is deployed by an electrical
signal generated by the Airbag Control Module
(ACM) through the passenger airbag squib circuits to
the initiator in the airbag inflator. The hybrid-type
inflator assembly includes a small canister of highly
compressed inert gas. When the ACM sends the
proper electrical signal to the airbag inflator, the ini-
tiator converts the electrical energy into chemical
energy. This chemical energy produces the pressure
necessary to rupture a burst disk in the inert gas
canister.
The inflator is sealed to the airbag cushion so that
all of the released inert gas is directed into the air-
bag cushion, causing the cushion to inflate. As the
cushion inflates, the passenger airbag door will split
at predetermined tear seam lines concealed on the
inside surface of the door, then the door will pivot up
over the top of the instrument panel and out of the
way. Following a passenger airbag deployment, the
airbag cushion quickly deflates by venting the inert
gas through vent holes within the fabric used to con-
struct the back (instrument panel side) of the airbag
cushion.
REMOVAL
The following procedure is for replacement of a
faulty or damaged passenger airbag. If the airbag is
faulty or damaged, but not deployed, review the rec-
ommended procedures for handling non-deployed
supplemental restraints. (Refer to 8 - ELECTRICAL/
RESTRAINTS - STANDARD PROCEDURE - HAN-
DLING NON-DEPLOYED SUPPLEMENTAL
RESTRAINTS). If the passenger airbag has been
deployed, review the recommended procedures for
service after a supplemental restraint deploymentFig. 31 Passenger Airbag Unit
1 - DOOR
2 - PANEL OUTLET HOUSING (2)
3 - SNAP FEATURE (7)
4 - REAR BRACKET (2)
5 - PIGTAIL WIRE CONNECTOR
6 - INFLATOR
7 - FRONT BRACKET (2)
8 - HOUSING
DRRESTRAINTS 8O - 35
PASSENGER AIRBAG (Continued)

REMOVAL
Depending on engine control computer (JTEC
having a 3±plug connector or 5.7L V-8 NGC hav-
ing a 4±plug connector), 2 types of switches are
used. Both types of switches are internally and
externally different. The switches used with the
NGC system have attached pigtail leads (Fig.
11). The switch used with the JTEC system does
not have an attached pigtail lead.
(1) Remove switch mounting screw (Fig. 10). or
(Fig. 11)
(2) Pull switch from steering wheel.
(3) Unplug electrical connector from switch (Fig.
10), or, switch pigtail wire harness from steering
wheel wire harness (Fig. 11) and remove switch.
INSTALLATION
(1) Plug electrical connector into switch (Fig. 10),
or connect pigtail wire harness to steering wheel wire
harness (Fig. 11). Be sure wires are not pinched.
(2) Position switch to steering wheel.
(3) Install switch mounting screw and tighten.
Refer to torque specifications.
VACUUM RESERVOIR
DESCRIPTION
The vacuum reservoir is a plastic storage tank con-
nected to an engine vacuum source by vacuum lines.
A vacuum reservoir is not used with diesel engines or
the 5.7L gas powered engine.
OPERATION
The vacuum reservoir is used to supply the vac-
uum needed to maintain proper speed control opera-
tion when engine vacuum drops, such as in climbing
a grade while driving. A one-way check valve is used
in the vacuum line between the reservoir and the
vacuum source. This check valve is used to trap
engine vacuum in the reservoir. On certain vehicle
applications, this reservoir is shared with the heat-
ing/air-conditioning system. The vacuum reservoir
cannot be repaired and must be replaced if faulty.
DIAGNOSIS AND TESTING - VACUUM
RESERVOIR
(1) Disconnect vacuum hose at speed control servo
and install a vacuum gauge into the disconnected
hose.
Fig. 10 SPEED CONTROL SWITCHES (EXCEPT 5.7L
V-8 ENGINE)
1 - ELECTRICAL CONNECTORS
2 - MOUNTING SCREWS
3 - RIGHT SWITCH
4 - LEFT SWITCH
Fig. 11 SPEED CONTROL SWITCHES (WITH 5.7L V-8
ENGINE)
1 - MOUNTING SCREWS
2 - RIGHT SWITCH
3 - LEFT SWITCH
4 - PIGTAIL LEADS
DRSPEED CONTROL 8P - 9
SWITCH (Continued)

WIRING
TABLE OF CONTENTS
page page
WIRING DIAGRAM INFORMATION....... 8W-01-1
COMPONENT INDEX.................. 8W-02-1
POWER DISTRIBUTION............... 8W-10-1
GROUND DISTRIBUTION.............. 8W-15-1
BUS COMMUNICATIONS.............. 8W-18-1
CHARGING SYSTEM.................. 8W-20-1
STARTING SYSTEM.................. 8W-21-1
FUEL/IGNITION SYSTEM.............. 8W-30-1
TRANSMISSION CONTROL SYSTEM..... 8W-31-1
VEHICLE SPEED CONTROL............ 8W-33-1
REAR WHEEL ANTILOCK BRAKES....... 8W-34-1
ALL WHEEL ANTILOCK BRAKES........ 8W-35-1
VEHICLE THEFT SECURITY SYSTEM..... 8W-39-1
INSTRUMENT CLUSTER............... 8W-40-1
HORN/CIGAR LIGHTER/POWER OUTLET . . 8W-41-1
AIR CONDITIONING.................. 8W-42-1
AIRBAG SYSTEM.................... 8W-43-1INTERIOR LIGHTING.................. 8W-44-1
AUDIO SYSTEM..................... 8W-47-1
OVERHEAD CONSOLE................. 8W-49-1
FRONT LIGHTING.................... 8W-50-1
REAR LIGHTING..................... 8W-51-1
TURN SIGNALS...................... 8W-52-1
WIPERS............................ 8W-53-1
TRAILER TOW....................... 8W-54-1
POWER WINDOWS................... 8W-60-1
POWER DOOR LOCKS................ 8W-61-1
POWER MIRRORS................... 8W-62-1
POWER SEATS...................... 8W-63-1
SPLICE INFORMATION................ 8W-70-1
CONNECTOR PIN-OUTS............... 8W-80-1
CONNECTOR/GROUND/SPLICE
LOCATION........................ 8W-91-1
POWER DISTRIBUTION............... 8W-97-1 DRWIRING 8W - 1

8W-42 AIR CONDITIONING
Component Page
A/C Compressor Clutch............... 8W-42-7
A/C Compressor Clutch Relay.......... 8W-42-7
A/C Pressure Transducer............ 8W-42-8, 9
A/C-Heater Control........... 8W-42-2, 3, 4, 5, 6
Blend Door Actuator.................. 8W-42-6
Blower Motor....................... 8W-42-2
Blower Motor Resistor Block........... 8W-42-2
Condenser Fan..................... 8W-42-10
Condenser Fan Relay................ 8W-42-10
Data Link Connector............. 8W-42-3, 4, 8
Driver Blend Door Actuator............ 8W-42-5
Engine Control Module.............. 8W-42-7, 9
Evaporator Temperature Sensor......... 8W-42-4
Fuse 12........................... 8W-42-10
Fuse 16............................ 8W-42-7
Fuse 36............................ 8W-42-3
Fuse 36............................ 8W-42-4Component Page
G107.............................. 8W-42-7
G120.............................. 8W-42-7
G202.............................. 8W-42-3
G202.............................. 8W-42-4
G203.............................. 8W-42-2
Heated Mirror Relay............... 8W-42-3, 4
Ignition Switch...................... 8W-42-2
Instrument Cluster................... 8W-42-2
Integrated Power Module....... 8W-42-3, 4, 7, 10
Mode Door Actuator 1............... 8W-42-5, 6
Mode Door Actuator 2............... 8W-42-5, 6
Passenger Blend Door Actuator......... 8W-42-5
Powertrain Control Module........ 8W-42-7, 8, 10
PTCNo.1.......................... 8W-42-7
Recirculation Door Actuator.......... 8W-42-5, 6
DR8W-42 AIR CONDITIONING 8W - 42 - 1

(17) Connect the engine to body ground straps at
the left side of the cowl.
(18) Install the intake manifold.
(19) Install the engine oil dipstick tube.
(20) Install the power brake booster vacuum hose.
(21) Install the breather hoses.
(22) Install the PCV hose.
(23) Install the fuel rail.
(24) Install the coil over plugs.
(25) Connect the engine wiring harness at the fol-
lowing points:
²Intake air temperature (IAT) sensor
²Fuel Injectors
²Throttle Position (TPS) Switch
²Idle Air Control (IAC) Motor
²Engine Oil Pressure Switch
²Engine Coolant Temperature (ECT) Sensor
²Manifold Absolute Pressure MAP) Sensor
²Camshaft Position (CMP) Sensor
²Coil Over Plugs
²Crankshaft Position Sensor
(26) Reinstall the radiator/cooling module assem-
bly.
(27) Connect lower radiator hose.
(28) Connect upper radiator hose.
(29) Connect throttle and speed control cables.
(30) Install the heater hose assembly.
(31) Install coolant recovery bottle.
(32) Install the power steering pump.
(33) Install the generator.
(34) Install the A/C compressor.
(35) Install the drive belt.
(36) Install the fan shroud with the viscous fan
assembly.
(37) Install the radiator core support bracket.
(38) Install the air cleaner assembly.
(39) Refill the engine cooling system.
(40) Recharge the air conditioning.
(41) Install the hood.
(42) Check and fill engine oil.
(43) Connect the battery negative cable.
(44) Start the engine and check for leaks.SPECIFICATIONS
SPECIFICATIONS ± 3.7L ENGINE
DESCRIPTION SPECIFICATION
Engine Type 90É SOHC V-6 12-Valve
Displacement 3.7 Liters / 3700 cc
226 ( Cubic Inches)
Bore 93.0 mm (3.66 in.)
Stroke 90.8 mm (3.40 in.)
Compression Ratio 9.1:1
Horsepower 210 BHP @ 5200 RPM
Torque 225 LB-FT @ 4200 RPM
Lead Cylinder #1 Left Bank
Firing Order 1-6-5-4-3-2
CYLINDER BLOCK
Cylinder Block Cast Iron
Bore Diameter 93.0   .0075 mm
(3.6619   0.0003 in.)
Out of Round (MAX) 0.076 mm (0.003 in.)
Taper (MAX) 0.051 mm (0.002 in.)
PISTONS
Material Aluminum Alloy
Diameter 92.975 mm (3.6605 in.)
Weight 367.5 grams (12.96 oz)
Ring Groove Diameter
No. 1 83.73 - 83.13 mm
(3.296 - 3.273 in.)
No. 2 82.833 - 83.033 mm
(3.261 - 3.310 in.)
No. 3 83.88 - 84.08 mm
(3.302 - 3.310 in.)
PISTON PINS
Type Floating
Clearance In Piston 0.006 - 0.015 mm
(0.0002 - 0.0005 in.)
Diameter 24.017 - 24.020 mm
(0.9455 - 0.9456 in.)
PISTON RINGS
Ring Gap
Top Compression Ring 0.20 - 0.36 mm
(0.0079 - 0.0142 in.)
9 - 12 ENGINE - 3.7LDR
ENGINE - 3.7L (Continued)

(8) Starting at the outside working inward, loosen
the camshaft bearing cap retaining bolts 1/2 turn at
a time. Repeat until all load is off the bearing caps.
CAUTION: DO NOT STAMP OR STRIKE THE CAM-
SHAFT BEARING CAPS. SEVERE DAMAGE WILL
OCCUR TO THE BEARING CAPS.
NOTE: When the camshaft is removed the rocker
arms may slide downward, mark the rocker arms
before removing camshaft.
(9) Remove the camshaft bearing caps and the
camshaft.
INSTALLATION
(1) Lubricate camshaft journals with clean engine
oil.
NOTE: Position the right side camshaft so that the
camshaft sprocket dowel is near the 10 o'clock
position, This will place the camshaft at the neutral
position easing the installation of the camshaft
bearing caps.
(2) Position the camshaft into the cylinder head.
(3) Install the camshaft bearing caps, hand tighten
the retaining bolts.
NOTE: Caps should be installed so that the
stamped numbers on the caps are in numerical
order, ( 1 thru 4 ) from the front to the rear of the
engine. All caps should be installed so that the
stamped arrows on the caps point toward the front
of the engine.
(4) Working in 1/2 turn increments, tighten the
bearing cap retaining bolts starting with the middle
cap working outward (Fig. 27).
(5) Torque the camshaft bearing cap retaining
bolts to 11 N´m (100 in. lbs.).
(6) Position the camshaft drive gear into the tim-
ing chain aligning the V6 mark between the two
marked chain links (Two links marked during remov-
al).
(7) Using Special Tool 8428 Camshaft Wrench,
rotate the camshaft until the camshaft sprocket
dowel is aligned with the slot in the camshaft
sprocket. Install the sprocket onto the camshaft.
CAUTION: Remove excess oil from camshaft
sprocket bolt. Failure to do so can cause bolt over-
torque resulting in bolt failure.
(8) Remove excess oil from camshaft sprocket bolt,
then install the camshaft sprocket retaining bolt and
hand tighten.(9) Remove timing chain wedge special tool 8379.
(10) Using Special Tool 6958 spanner wrench with
adapter pins 8346, torque the camshaft sprocket
retaining bolt to 122 N´m (90 ft. lbs.).
(11) Install the camshaft position sensor.
(12) Install the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
CYLINDER HEAD COVER(S)
REMOVAL
(1) Disconnect battery negative cable.
(2) Remove air cleaner assembly, resonator assem-
bly and air inlet hose.
(3) Drain cooling system, below the level of the
heater hoses(Refer to 7 - COOLING - STANDARD
PROCEDURE).
(4) Remove accessory drive belt(Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - REMOV-
AL).
(5) Remove air conditioning compressor retaining
bolts and move compressor to the left.
(6) Remove heater hoses.
(7) Disconnect injector and ignition coil connectors.
(8) Disconnect and remove positive crankcase ven-
tilation (PCV) hose.
(9) Remove oil fill tube.
(10) Un-clip injector and ignition coil harness and
move away from cylinder head cover.
(11) Remove right rear breather tube and filter
assembly.
Fig. 27 CAMSHAFT BEARING CAPS TIGHTENING
DRENGINE - 3.7L 9 - 35
CAMSHAFT(S) (Continued)

(12) Remove cylinder head cover retaining bolts.
(13) Remove cylinder head cover.
INSTALLATION
CAUTION: Do not use harsh cleaners to clean the
cylinder head covers. Severe damage to covers
may occur.
NOTE: The gasket may be used again, provided no
cuts, tears, or deformation has occurred.
(1) Clean cylinder head cover and both sealing sur-
faces. Inspect and replace gasket as necessary.
(2) Tighten cylinder head cover bolts and double
ended studs to 12 N´m (105 in. lbs).
(3) Install right rear breather tube and filter
assembly.
(4) Connect injector, ignition coil electrical connec-
tors and harness retaining clips.
(5) Install the oil fill tube.
(6) Install PCV hose.
(7) Install heater hoses.
(8) Install air conditioning compressor retaining
bolts.
(9) Install accessory drive belt(Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(10) Fill Cooling system(Refer to 7 - COOLING -
STANDARD PROCEDURE).
(11) Install air cleaner assembly, resonator assem-
bly and air inlet hose.
(12) Connect battery negative cable.
ROCKER ARM
DESCRIPTION
The rocker arms are steel stampings with an inte-
gral roller bearing. The rocker arms incorporate a 2.8
mm (0.11 inch) oil hole in the lash adjuster socket for
roller and camshaft lubrication.
REMOVAL
NOTE: Disconnect the battery negative cable to pre-
vent accidental starter engagement.
(1) Remove the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(2) For rocker arm removal on cylinder #4, Rotate
the crankshaft until cylinder #1 is at BDC intake
stroke.(3) For rocker arm removal on cylinder #1, Rotate
the crankshaft until cylinder #1 is at BDC combus-
tion stroke.
(4) For rocker arm removal on cylinders #3 and #5,
Rotate the crankshaft until cylinder #1 is at TDC
exhaust stroke.
(5) For rocker arm removal on cylinders #2 and #6,
Rotate the crankshaft until cylinder #1 is at TDC
ignition stroke.
(6) Using special tool 8516 Rocker Arm Remover,
press downward on the valve spring, remove rocker
arm (Fig. 28).
VALVE GUIDE SEALS
DESCRIPTION
The valve guide seals are made of rubber and
incorporate an integral steel valve spring seat. The
integral garter spring maintains consistent lubrica-
tion control to the valve stems.
VALVE SPRINGS
DESCRIPTION
The valve springs are made from high strength
chrome silicon steel. There are different springs for
intake and exhaust applications. The valve spring
seat is integral with the valve stem seal, which is a
positive type seal to control lubrication.
Fig. 28 Rocker Arm - Removal
1 - CAMSHAFT
2 - SPECIAL TOOL 8516
9 - 36 ENGINE - 3.7LDR
CYLINDER HEAD COVER(S) (Continued)

(2) Spray a small stream of water (spray bottle) at
the suspected leak area.
(3) If engine RPM'S change, the area of the sus-
pected leak has been found.
(4) Repair as required.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove resonator assembly and air inlet hose.
(3) Disconnect throttle and speed control cables.
(4) Disconnect electrical connectors for the follow-
ing components: Refer to FUEL SYSTEM for compo-
nent locations.
²Manifold Absolute Pressure (MAP) Sensor
²Intake Air Temperature (IAT) Sensor
²Throttle Position (TPS) Sensor
²Coolant Temperature (CTS) Sensor
²Idle Air Control (IAC) Motor
(5) Disconnect vapor purge hose, brake booster
hose, speed control servo hose, positive crankcase
ventilation (PCV) hose.
(6) Disconnect generator electrical connections.
(7) Disconnect air conditioning compressor electri-
cal connections.(8) D
isconnect left and right radio suppressor straps.
(9) Disconnect and remove ignition coil towers.
(10) Remove top oil dipstick tube retaining bolt
and ground strap.
(11) Bleed fuel system. Refer to FUEL SYSTEM.
(12) Remove fuel rail.
(13) Remove throttle body assembly and mounting
bracket.
(14) Drain cooling system below coolant tempera-
ture level. Refer to COOLING SYSTEM.
(15) Remove the heater hoses from the engine
front cover and the heater core.
(16) Unclip and remove heater hoses and tubes
from intake manifold.
(17) Remove coolant temperature sensor. Refer to
FUEL SYSTEM.
(18) Remove intake manifold retaining fasteners in
reverse order of tightening sequence.
(19) Remove intake manifold.
INSTALLATION
(1) Install intake manifold gaskets.
(2) Install intake manifold.
(3) Install intake manifold retaining bolts and
tighten in sequence shown in to 12 N´m (105 in. lbs.)
(Fig. 90).
(4) Install left and right radio suppressor straps.
(5) Install throttle body assembly.
(6) Connect throttle cable and speed control cable
to throttle body.
(7) Install fuel rail.
(8) Install ignition coil towers.
Fig. 89 Intake Manifold
1 - THROTTLE BODY
2 - INTAKE MANIFOLD
3 - INTAKE PORT GASKETS
Fig. 90 Intake Manifold Tightening Sequence
9 - 72 ENGINE - 3.7LDR
INTAKE MANIFOLD (Continued)

CAUTION: Use care when removing the idler shaft,
Do not strike the radiator cooling fins with the slide
hammer.
(4) Using Special Tool 8517 Slide Hammer, remove
the idler shaft.
INSTALLATION
(1) Thoroughly clean the idler shaft bore.
(2) Position the idler shaft in the bore.
NOTE: The two lubrication holes in the idler shaft
do not require any special alignment.
NOTE: Before using the retaining bolt to install the
idler shaft, coat the threads and the pilot on the
idler shaft, with clean engine oil.
(3) Using the primary idler sprocket retaining bolt
and washer, carefully draw the idler shaft into the
bore until fully seated.
(4) Coat the idler shaft with clean engine oil.
(5) Install the timing chains and sprockets. Refer
to procedure in this section.
TIMING BELT / CHAIN
COVER(S)
REMOVAL
(1) Disconnect the battery negative cable.
(2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Remove electric cooling fan and fan shroud
assembly.
(4) Remove fan and fan drive assembly (Refer to 7
- COOLING/ENGINE/FAN DRIVE VISCOUS
CLUTCH - REMOVAL).
(5) Disconnect both heater hoses at timing cover.
(6) Disconnect lower radiator hose at engine.
(7) Remove accessory drive belt tensioner assembly
(Fig. 103).
(8) Remove crankshaft damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL).
(9) Remove the generator (Refer to 8 - ELECTRI-
CAL/CHARGING/GENERATOR - REMOVAL).
(10) Remove A/C compressor (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/A/C COM-
PRESSOR - REMOVAL).
CAUTION: The 3.7L engine uses an anerobic sealer
instead of a gasket to seal the front cover to the
engine block, from the factory. For service, MoparT
Engine RTV sealant must be substituted.NOTE: It is not necessary to remove the water
pump for timing cover removal.
(11) Remove the bolts holding the timing cover to
engine block (Fig. 104).
(12) Remove the timing cover.
Fig. 103 ACCESSORY DRIVE BELT TENSIONER
1 - TENSIONER ASSEMBLY
2 - FASTENER TENSIONER TO FRONT COVER
Fig. 104 TIMING CHAIN COVER FASTENERS
9 - 80 ENGINE - 3.7LDR
IDLER SHAFT (Continued)