1999 DODGE RAM engine oil

Fig. 6: Locating Intake Manifold Air Heater Relays
Courtesy of Chrysler Corp.
Malfunction Indicator Light (MIL)
The MIL is located on the instrument panel, just below
tachometer and may also be referred to as the CHECK ENGINE light. MIL
comes on for a short period and then goes off as a bulb and wiring
circuit test each time ignition switch is turned to the ON position.
If Engine Control Module (ECM) receives an incorrect signal or
receives no signal from certain sensors or components, ECM will turn
on the MIL to warn the driver that a malfunction exists in the
electronic system.
Oil Pressure Gauge/Warning Light
Oil pressure gauge/warning light output from Engine Control
Module (ECM) to instrument cluster is routed on CCD Bus circuit.


E - T H EO RY/O PER ATIO N - R W D - G ASO LIN E

1999 D odge P ic ku p R 1500
1999 ENGINE PERFORMANCE
CHRY - Theory & Operation - Trucks & RWD Vans - Gasoline
Dakota, Durango, Ram Pickup, Ram Van, Ram Wagon
INTRODUCTION
This article covers the basic description and operation of
engine performance related systems and components. Read this article
before working on unfamiliar systems.
COMPUTERIZED ENGINE CONTROLS
POWERTRAIN CONTROL MODULE (PCM)
The PCM is a digital computer that controls ignition timing,
air/fuel ratio, fuel injector pulse width, ignition coil(s), spark
advance, emission control devices, cooling fan, charging system, idle
speed, cruise control (if equipped), fuel pump and tachometer. For PCM\
location, see PCM LOCATION. PCM uses data from various input sources
to control output devices in order to achieve optimum engine
performance for all operating conditions.
PCM has voltage converters that convert battery voltage to
regulated 5-volt output. The 5-volt output powers battery temperature
sensor, Camshaft Position (CMP) sensor on models equipped with
Distributorless Ignition System (DIS) or distributor on models without\
DIS, Crankshaft Position (CKP) sensor, Engine Coolant Temperature
(ECT) sensor, Intake Air Temperature (IAT) sensor, logic circuits,
Manifold Absolute Pressure (MAP) sensor, Throttle Position (TP) sens\
or
and Vehicle Speed Sensor (VSS) on some models.
PCM LOCATION









\









\









\









\









\









\









\







Application Location
Dakota & Durango ................. Right Front Fender, Near Firewall
Ram Pickup, Ram Van & Ram Wagon .... On Firewall, Near Wiper Motor









\









\









\









\









\









\









\







NOTE: Components are grouped into 2 categories. The first category,
INPUT DEVICES, includes components that control or produce
voltage signals monitored by the PCM. The second category,
OUTPUT SIGNALS, includes components controlled by the PCM
(this is accomplished by the PCM grounding individual
circuits).
INPUT DEVICES
Vehicles are equipped with different combinations of input
devices. Not all devices are used on all models. To determine
component location and input usage on a specific model, see
appropriate wiring diagram in WIRING DIAGRAMS article. Available input
signals include:
A/C Switch
Switch signals PCM that A/C has been selected. PCM then
activates A/C compressor clutch relay and maintains idle speed at a
preprogrammed RPM. This is done through control of Idle Air Control

drive plate. PCM uses this information to determine fuel injection
sequence, ignition signal and spark timing.
Cruise Control Switch
Cruise control switch provides PCM with 3 separate inputs.
ON/OFF switch input informs PCM that cruise control system has been
activated. SET/COAST switch input informs PCM that set vehicle speed
has been selected, or if depressed will decelerate until switch is
released. RESUME/ACCEL switch input informs PCM that a previously set
speed has been selected or, if depressed, will increase speed until
released. PCM uses these inputs to control cruise control servo.
Engine Coolant Temperature (ECT) Sensor
ECT sensor monitors engine coolant temperature. PCM uses ECT
sensor information to adjust air/fuel mixture and idle speed and to
control radiator cooling fans as necessary.
Fuel Level Sensor
PCM supplies a 5-volt reference signal to fuel module in gas
tank. Fuel level sensor sends a signal to PCM indicating fuel level.
PCM monitors this signal to prevent a false misfire signal if fuel
level is less than 15 percent. PCM also sends this signal to fuel
gauge.
Heated Oxygen Sensor (HO2S)
HO2S produces a small electrical voltage (0-1 volt) when
exposed to heated exhaust gas. HO2S is electrically heated for faster
warm-up. Heating element is powered through Auto Shutdown (ASD) relay.\
HO2S acts like a rich/lean (air/fuel ratio) switch by
monitoring oxygen content in exhaust gas. This information is used by
PCM to adjust air/fuel ratio by adjusting injector pulse width.
HO2S produces low voltage when oxygen content in exhaust gas
is high. When oxygen content in exhaust gas is low, HO2S produces a
higher voltage.
Ignition Switch
Ignition switch sends signal to PCM indicating whether switch
is on, off or cranking (ST). When PCM receives ON signal, it energizes\
ASD relay coil and supplies power to sensors and actuators. When PCM
receives ST signal, it controls fuel injection rate, idle speed,
ignition timing, etc. for optimum cranking conditions.
Intake Air Temperature (IAT) Sensor
IAT sensor measures temperature of incoming intake air. This
information is used by PCM to adjust air/fuel mixture.
Manifold Absolute Pressure (MAP) Sensor
MAP sensor monitors intake manifold vacuum. Sensor transmits
information on manifold vacuum and barometric pressure to PCM. MAP
sensor information is used with information from other sensors to
adjust air/fuel mixture.
Oil Pressure Sensor
Sensor sends a signal to PCM to indicate oil pressure.
Park/Neutral (P/N) Switch (A/T Models)
This switch may also be referred to as a Park/Neutral
Position (PNP) switch. P/N switch is available on vehicles equipped
with A/T only. Switch prevents engine starter from engaging if vehicle
is in any gear except Park or Neutral.
P/N switch input (varied with gear selection) is used to
determine idle speed, fuel injector pulse and ignition timing.

various switch input operations to adjust IAC motor to obtain optimum
idle conditions. Deceleration stall is prevented by increasing airflow
when throttle is closed suddenly.
IGNITION SYSTEM
NOTE: Pickup equipped with 8.0L engine uses Distributorless
Ignition system (DIS). All other models use a Hall Effect
ignition system.
The PCM completely controls ignition system. During
crank/start mode, PCM will set a fixed amount of spark advance for an
efficient engine start. Amount of spark advance or retard is
determined by inputs that PCM receives from ECT sensor, engine vacuum
and engine RPM. During engine operation, PCM can supply an infinite
number of advance curves to ensure proper engine operation.
DISTRIBUTORLESS IGNITION SYSTEM (DIS)
DIS eliminates mechanical ignition components that can wear
out. PCM has complete ignition control and uses a coil pack, CMP
sensor and CKP sensor to control ignition timing. CMP sensor reads
slots in cam timing sprocket. PCM uses this information along with
information from CKP sensor to determine if fuel injectors and
ignition coils are properly sequenced for correct cylinders.
Basic timing is determined by CKP sensor position and is not
adjustable. One complete engine revolution may be required for PCM to
determine crankshaft position during cranking.
Molded ignition coils are used. Each coil fires 2 paired
spark plugs at the same time. One cylinder is on compression stroke
and other cylinder is on exhaust stroke.
HALL EFFECT IGNITION SYSTEM
This system is equipped with a Hall Effect distributor. See
Fig. 1 . Shutter(s) attached to distributor shaft rotate through
distributor Hall Effect switch, also referred to as a CMP sensor,
which contains a distributor pick-up (a Hall Effect device and
magnet). As shutter blade(s) pass through pick-up, magnetic field is
interrupted and voltage is toggled between high and low. PCM uses this
cylinder position data from CMP sensor, along with engine speed (RPM)
and CKP sensor data, to control ignition timing and injector pulse
width to maintain optimum driveability.
EMISSION SYSTEMS
Vehicles are equipped with different combinations of emission
system components. Not all components are used on all models. To
determine component usage on a specific model, see EMISSION
APPLICATIONS - TRUCKS article.
AIR INJECTION SYSTEM
This system adds a controlled amount of air to exhaust gases,
through air relief valve and check valves, to assist oxidation of
hydrocarbons and carbon monoxide in exhaust stream. Air is injected at
catalytic converters.
CRANKCASE VENTILATION (CCV) SYSTEM
CCV system performs same function as a conventional Positive

PCM.
MISCELLANEOUS CONTROLS
NOTE: Although not strictly considered part of engine performance
system, some controlled devices can adversely affect
driveability if they malfunction.
A/C CLUTCH RELAY
A/C clutch relay is controlled by PCM. When A/C or Defrost
mode is selected and PCM receives A/C request signal from evaporator
switch, PCM will cycle clutch on and off through A/C clutch relay.
When this relay is energized during engine operation, PCM will
determine correct engine idle speed through IAC motor.
When PCM senses low idle speed or wide open throttle through
TP sensor, PCM will de-energize A/C clutch relay, preventing A/C
operation.
AUTO SHUTDOWN (ASD) RELAY & FUEL PUMP RELAY
ASD relay and electric fuel pump relay are energized when
ignition is on. These relays are controlled through PCM by switching a
common ground circuit on and off. Following components are controlled
by ASD and fuel pump relays:
* Electric Fuel Pump
* Fuel Injectors
* Generator Field Winding
* Ignition Coil(s)
* HO2S Heating Element
When ignition switch is turned to RUN position, PCM energizes
ASD relay and electric fuel pump relay which powers these components.
If PCM does not receive a CMP and CKP sensor signal within one second
of engine cranking (start-up), PCM will turn ground circuit off and
de-energize ASD relay.
GENERATOR
Powertrain Control Module (PCM) regulates charging system
voltage.
LIMP-IN MODE
Limp-in mode is the attempt by PCM to compensate for failure
of certain components by substituting information from other sources
so that vehicle can still be operated. If PCM senses incorrect data or
no data at all from MAP sensor, TP sensor, ECT sensor or battery
voltage, system is placed into limp-in mode and Malfunction Indicator
Light (MIL) on instrument panel comes on.
If faulty sensor comes back on line, PCM will resume closed
loop operation. On some vehicles, MIL will remain on until ignition is
shut off and vehicle is restarted. To prevent damage to catalytic
converter, vehicle should NOT be driven for extended periods in limp-
in mode.
RADIATOR FAN RELAY
Electric cooling fan is used only on Dakota. Using
information supplied by A/C signal (if equipped), ECT sensor, and VSS,\

TR AN SM IS SIO N R EM OVA L & IN STA LLA TIO N

1999 D odge P ic ku p R 1500
1998-99 TRANSMISSION SERVICING
CHRY - Trans Removal & Installation - Trucks & RWD Vans
Dakota, Ram Pickup, Ram Van/Wagon
WARNING: When battery is disconnected, vehicle computer and memory
systems may lose memory data. Driveability problems may exist
until computer systems have completed a relearn cycle. See
COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION
before disconnecting battery.
MANUAL TRANSMISSION
NOTE: For manual transmission replacement procedures, see
appropriate article in CLUTCHES.
AUTOMATIC TRANSMISSION
DAKOTA & DURANGO
Removal
1) Disconnect negative battery cable. Raise and support
vehicle. Disconnect and remove necessary skid plates and exhaust
components for transmission removal. Remove engine-to-transmission
struts (if equipped). These struts are located between front of
transmission and engine.
2) Ensure area around transmission oil cooler lines fitting
are clean. Disengage retainer on quick-disconnect cooler line fitting.
Pull cooler line from transmission oil cooler.
CAUTION: Crankshaft position sensor must be removed from transmission
housing before removing transmission to prevent damage to
crankshaft position sensor.
3) Remove starter. Disconnect electrical connector for
crankshaft position sensor. On 2.5L, crankshaft position sensor is
mounted on driver's side of transmission housing. See Fig. 1. On 3.9L,
5.2L and 5.9L, crankshaft position sensor is mounted on passenger's
side of transmission housing. See Fig. 2.
4) Remove crankshaft position sensor bolts or nuts. Remove
crankshaft position sensor from transmission housing. Remove dipstick,
dipstick tube and "O" ring from transmission.
5) Remove torque converter cover. Place reference mark on
flexplate and torque converter for installation reference. Rotate
crankshaft clockwise and remove torque converter bolts.
6) Place reference mark on drive shaft flanges for
installation reference. Remove drive shaft from transmission. On 4WD
models, disconnect drive shaft from transfer case. Disconnect shift
rod for transfer case from transfer case shift lever.
7) On all models, disconnect necessary control cables, wiring
harnesses, and shift linkage or cable from transmission. Support rear
of engine with jack stand. Using transmission jack, slightly raise
transmission to release pressure from rear mount and rear crossmember.
8) Remove bolts securing rear support and rear mount to
transmission and rear crossmember. Raise transmission slightly. Slide
exhaust hanger arm from bracket on rear support. Remove rear support
and rear mount.
9) Remove rear crossmember located below the transmission. On
4WD models, disconnect electrical connectors from transfer case. On

Courtesy of Chrysler Corp.
Installation
1) To install, reverse removal procedure. Ensure torque
converter is fully seated in transmission by measuring distance from
cylinder block surface on transmission housing to front edge on torque
converter bolt lug on front of torque converter. Distance should be .
50" (12.7 mm) if torque converter is fully seated.
CAUTION: Proper length torque converter bolts must be used. If
replacing any torque converter bolts, ensure proper length
bolt is used.
2) Tighten bolt/nuts to specification. See TORQUE
SPECIFICATIONS. Ensure reference mark on torque converter and
flexplate, and drive shaft flanges are aligned. Adjust shift cable or
linkage, throttle valve cable and transfer case shift linkage if
necessary. See AUTOMATIC TRANSMISSION - TRUCKS & RWD VANS article.
3) Use NEW "O" ring when installing dipstick tube. Before
installing oil cooler lines on transmission, ensure all fittings are
clean. Install oil cooler line into quick-disconnect fitting. Push oil
cooler line inward until a click is heard. Pull on oil cooler line to
ensure oil cooler line is locked in place. Fill transmission with
Mopar ATF Plus Type 7176.
RAM PICKUP
Removal
1) Disconnect negative battery cable. Raise and support
vehicle. Disconnect and remove necessary skid plates and exhaust
components for transmission removal. Remove engine-to-transmission
struts (if equipped). These struts are located between front of
transmission and engine.
2) Ensure area around transmission oil cooler lines fitting
are clean. Disengage retainer on quick-disconnect cooler line fitting.
Pull cooler line from transmission oil cooler. Remove starter.
CAUTION: On 3.9L, 5.2L and 5.9L gasoline models, crankshaft position
sensor must be removed from transmission housing before
removing transmission to prevent damage to crankshaft
position sensor.
3) On 3.9L, 5.2L and 5.9L gasoline models, disconnect
electrical connector for crankshaft position sensor. Crankshaft
position sensor is mounted on passenger's side of transmission
housing. See Fig. 2.
4) Remove crankshaft position sensor bolts. Remove crankshaft
position sensor from transmission housing. Remove dipstick, dipstick
tube and "O" ring from transmission.
5) Remove torque converter cover. Place reference mark on
flexplate and torque converter for installation reference. Rotate
crankshaft clockwise and remove torque converter bolts.
6) Place reference mark on drive shaft flanges for
installation reference. Remove drive shaft from transmission. On 4WD
models, disconnect drive shaft from transfer case. Disconnect shift
rod for transfer case from transfer case shift lever.
7) On all models, disconnect necessary control cables, wiring
harnesses, and shift linkage from transmission. Support rear of engine
with jack stand. Using transmission jack, slightly raise transmission
to release pressure from rear mount and rear crossmember.
8) Remove bolts securing rear support and rear mount to
transmission and rear crossmember. Raise transmission slightly. Slide
exhaust hanger arm from bracket on rear support. Remove rear support

and rear mount.
9) Remove rear crossmember located below the transmission. On
4WD models, disconnect electrical connectors from transfer case. On
all models, remove transmission-to-cylinder block bolts. Slide
transmission rearward from dowels on cylinder block.
10) Install "C" clamp on edge of transmission housing to hold
torque converter in place. Lower transmission and remove transmission
from vehicle.
Installation
1) To install, reverse removal procedure. Ensure torque
converter is fully seated in transmission by measuring distance from
cylinder block surface on transmission housing to front edge on torque
converter bolt lug on front of torque converter. Distance should be .
50" (12.7 mm) if torque converter is fully seated.
CAUTION: Proper length torque converter bolts must be used. If
replacing any torque converter bolts, consult parts
department to ensure proper length bolt is used.
2) Tighten bolt/nuts to specification. See TORQUE
SPECIFICATIONS. Ensure reference mark on torque converter and
flexplate, and drive shaft flanges are aligned. Adjust shift linkage,
throttle valve cable and transfer case shift linkage if necessary. See
AUTOMATIC TRANSMISSION - TRUCKS & RWD VANS article.
3) Use NEW "O" ring when installing dipstick tube. Before
installing oil cooler lines on transmission, ensure all fittings are
clean. Install oil cooler line into quick-disconnect fitting. Push oil
cooler line inward until a click is heard. Pull on oil cooler line to
ensure oil cooler line is locked in place. Fill transmission with
Mopar ATF Plus Type 7176.
RAM VAN/WAGON
Removal
1) Disconnect negative battery cable. Raise and support
vehicle. Remove engine-to-transmission struts. These struts are
located between front of transmission and engine.
2) Remove starter and oil cooler line bracket. Ensure area
around transmission oil cooler lines fitting are clean. Disengage
retainer on quick-disconnect cooler line fitting. Pull cooler line
from transmission oil cooler.
CAUTION: Crankshaft position sensor must be removed from transmission
housing before removing transmission to prevent damage to
crankshaft position sensor.
3) Disconnect electrical connector for crankshaft position
sensor. Crankshaft position sensor is mounted on passenger's side of
transmission housing. See Fig. 2.
4) Remove crankshaft position sensor bolts. Remove crankshaft
position sensor from transmission housing. Remove dipstick, dipstick
tube and "O" ring from transmission.
5) Remove torque converter cover. Place reference mark on
flexplate and torque converter for installation reference. Rotate
crankshaft clockwise and remove torque converter bolts.
6) Place reference mark on drive shaft yokes for installation
reference. Remove drive shaft from transmission. Disconnect necessary
wiring harnesses and control cables from transmission. Support rear of
engine with hoist. Using transmission jack, slightly raise
transmission to release pressure from rear mount and crossmember.
7) Remove rear mount-to-rear crossmember bolts. Remove bolts
and rear crossmember located below the transmission. Remove engine oil