1999 DODGE RAM low oil pressure

NOTE: For additional information on fuel pressure and fuel pump
testing procedures, see appropriate NO TROUBLE CODE (NTC)
TEST and NO START (NS) TEST in SELF-DIAGNOSTICS - JEEP,
TRUCKS & RWD VANS article.
Vehicles With Fuel Rail Test Port
1) Disconnect negative battery cable. Release fuel pressure.
See FUEL PRESSURE RELEASE. Install fuel pressure gauge with hose on
fuel pressure test port.
2) Start engine and allow to idle. Fuel pressure should be
44-54 psi (3.1-3.8 kg/cm
). If no fuel pressure exists and engine will
not start, fuel pump relay and control circuit may be defective. See
FUEL PUMP RELAY.
3) If fuel pressure exceeds specification, fuel pump is okay,
but fuel pressure regulator is defective. Replace fuel pressure
regulator. Fuel pressure regulator is incorporated with the fuel
filter. Fuel filter/fuel pressure regulator is located on top of fuel
tank, in fuel pump module. See REMOVAL, OVERHAUL & INSTALLATION -
TRUCKS & RWD VANS - GASOLINE article.
Vehicles Without Fuel Rail Test Port
1) Disconnect negative battery cable. Release fuel pressure.
See FUEL PRESSURE RELEASE. Fuel pressure gauge is installed between
fuel supply line and fuel line fitting on fuel rail.
2) To disconnect fuel supply line from fuel rail, ensure area
around fuel supply line and fuel rail are clean. Note direction of
latch clip installation. Latch clip is located on top of fuel supply
line at fuel rail. See Fig. 1. Using 2 screwdrivers, pry latch clip
upward, and remove from fuel rail.
3) Pull fuel supply line from fuel rail. Install Adapter
(6923) into fuel rail. Ensure adapter is fully seated in fuel rail.
Install latch clip into fuel rail, with latch clip fingers pointing
downward. If latch clip will not fully seat so latch clip fingers
extend downward below fitting on fuel rail, adapter may not be fully
seated in fuel rail.
4) Connect fuel supply line to adapter. Ensure fuel supply
line fully seats in adapter. Remove protective cap from test port, and
install Fuel Pressure Gauge/Hose (5069) at test port.
5) Start engine and allow to idle. Fuel pressure should be
44-54 psi (3.1-3.8 kg/cm
). If no fuel pressure exists and engine will
not start, fuel pump relay and control circuit may be defective. See
FUEL PUMP RELAY.
6) If fuel pressure exceeds specification, fuel pump is okay,
but fuel pressure regulator is defective. Replace fuel pressure
regulator. Fuel pressure regulator is incorporated with the fuel
filter. Fuel filter/fuel pressure regulator is located on top of fuel
tank, in fuel pump module. See REMOVAL, OVERHAUL & INSTALLATION -
TRUCKS & RWD VANS - GASOLINE article.
7) On all models, release fuel pressure. See FUEL PRESSURE
RELEASE. Remove latch clip. Remove test equipment. Before reinstalling
fuel supply line, ensure fuel supply line fitting and fitting on fuel
rail are clean.
8) Lubricate fuel supply line fitting and fitting on fuel
rail with engine oil. Install fuel supply line on fuel rail.
9) Install latch clip into fuel rail, with latch clip fingers
pointing downward. Ensure latch clip is fully seated. Latch clip
fingers should extend downward below fitting on fuel rail when fully
seated.
10) Pull on fuel supply line to ensure fuel supply line is
fully locked on fuel rail. Reinstall negative battery cable. Start
engine and check for fuel leaks.

BO DY C O NTR O L C O M PU TE R

1999 D odge P ic ku p R 1500
1999 ACCESSORIES & EQUIPMENT
CHRY - Body Control Computer Tests
Ram Pickup
NOTE: See BODY CONTROL COMPUTER - INTRODUCTION article before
proceeding with following test. Body control computer in RWD
trucks is the Central Timer Module (CTM).
SYMPTOM IDENTIFICATION
IDENTIFYING VEHICLE EQUIPMENT & SYSTEM PROBLEMS
NOTE: For connector terminal identification wiring diagrams, see
BODY CONTROL COMPUTER - INTRODUCTION article.
NOTE: Perform a visual inspection before proceeding with this test.
Ensure battery is fully charged.
1) Connect scan tool to Data Link Connector (DLC). DLC is a
16-pin connector located under left side of dash, to left of steering
wheel. Turn ignition switch to ON position. If scan tool display is
not blank, go to next step. If scan tool display is blank, see
appropriate VEHICLE COMMUNICATIONS article.
2) Using scan tool, select SYSTEM MONITORS, then CCD BUS
TEST. Scan tool will perform a CCD bus test. If scan tool displays BUS
OPERATIONAL, go to next step. If scan tool displays any message except
BUS OPERATIONAL, see appropriate VEHICLE COMMUNICATIONS article.
3) Using scan tool, select READ DTCs. If any Diagnostic
Trouble Codes (fault messages) are present, go to appropriate fault
message. If no fault messages are present, identify customer
complaint. See following list for possible fault messages and customer
complaint symptoms. Problems listed are diagnosed using a scan tool.
These problems may occur separately or in various combinations. When
diagnosing a system with many apparent problems, a sequence of tests
may be required. After repairs, ensure problem(s) or failure(s) have\
been corrected.
CHIME SYSTEM
* CHIME INOPERATIVE - ENGINE TEMPERATURE CRITICAL
* CHIME INOPERATIVE - KEY IN IGNITION & LF DOOR OPEN
* CHIME INOPERATIVE AT ALL TIMES
* CHIME INOPERATIVE WITH EXTERIOR LIGHTS ON
* CHIME INOPERATIVE WITH LOW OIL PRESSURE
* CHIME INOPERATIVE WITH DRIVER DOOR OPEN
DOOR AJAR SYSTEM
* OPEN LEFT DOOR AJAR CIRCUIT
* OPEN RIGHT DOOR AJAR CIRCUIT
* SHORTED LEFT DOOR AJAR CIRCUIT
* SHORTED RIGHT DOOR AJAR CIRCUIT
INSTRUMENT CLUSTER
* ALL GAUGES INOPERATIVE
* ANY CCD CLUSTER WARNING LIGHT INOPERATIVE
* ANY HARD WIRED CLUSTER WARNING LIGHT INOPERATIVE

between terminal No. 9 (Light Blue wire) and chassis ground. Using
scan tool, read key-in ignition switch status. If scan tool does not
display KEY-IN IGNITION CHIME STATE: ON, replace CTM. If scan tool
displays KEY-IN IGNITION CHIME STATE: ON, repair open Light Blue wire
between CTM and ignition switch.
CHIME INOPERATIVE AT ALL TIMES
NOTE: Perform VERIFICATION TEST VER-1A after each repair.
Turn ignition on. Using scan tool, select BODY SYSTEM, BODY
COMPUTER then ACTUATORS. Actuate chime. If chime sounds, system is
currently functioning correctly. If chime does not sound, replace
Central Timer Module (CTM). CTM is located under left side of
instrument panel.
CHIME INOPERATIVE WITH EXTERIOR LIGHTS ON
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting any module connector.
1) Remove ignition key. Using scan tool, read key-in ignition
chime state. If scan tool does not display KEY-IN IGNITION CHIME
STATE:
OFF, go to step 4). If scan tool displays KEY-IN IGNITION CHIME STATE:
OFF, go to next step.
2) Open driver's door. Using scan tool, read door ajar
status. If scan tool displays LFDOOR AJAR SWITCH: CLOSED, go to next
step. If scan tool does not display LFDOOR AJAR SWITCH: CLOSED, go to
OPEN LEFT DOOR AJAR CIRCUIT.
3) Turn on headlights. If chime does not sound, repair open
headlight sense circuit (Light Blue wire) between CTM and headlight
switch. See appropriate wiring diagram in BODY CONTROL COMPUTER -
INTRODUCTION article. If chime sounds, system is currently functioning
correctly.
4) Open driver's door. Using scan tool, read door ajar
status. If scan tool displays LFDOOR AJAR SWITCH: CLOSED, go to next
step. If scan tool does not display LFDOOR AJAR SWITCH: CLOSED, go to
OPEN LEFT DOOR AJAR CIRCUIT.
5) Disconnect key-in ignition switch connector. See Fig. 1.
Using scan tool, read key-in ignition chime state. If scan tool
displays KEY-IN IGNITION CHIME STATE: ON, go to next step. If scan
tool does not display KEY-IN IGNITION CHIME STATE: ON, replace
ignition switch. See appropriate STEERING COLUMN SWITCHES article.
6) Turn ignition off. Disconnect Central Timer Module (CTM).\
CTM is located under left side of instrument panel. Remove ignition
key. Ensure all lights and accessories are off. Close all doors. Using
external ohmmeter, measure resistance between ground and terminal No.
9 (Light Blue wire) on CTM Green connector "A". If resistance is less
than 10 ohms, repair Light Blue wire between CTM and ignition switch
for short to ground. If resistance is 10 ohms or more, replace CTM.
CHIME INOPERATIVE WITH LOW OIL PRESSURE
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to

disconnecting any module connector.
1) Disconnect Oil Pressure Switch (OPS). OPS is located near\
bottom of distributor. Connect a jumper wire between OPS connector
terminals. Start engine and allow to idle for 20 seconds. Increase
engine speed to 1600 RPM. If chime sounds, go to next step. If chime
does not sound, go to step 3).
2) Turn ignition on. Using scan tool, actuate chime. If chime
does not sound, replace Central Timer Module (CTM). CTM is located
under left side of instrument panel. If chime sounds, system is
currently functioning properly.
3) Using scan tool, access CLUSTER MONITOR. With engine
running, read CCD oil pressure. If scan tool reading does not match
instrument cluster reading, replace instrument cluster. If scan tool
reading matches instrument cluster reading, go to next step.
4) Remove jumper wire. Connect a jumper wire between ground
and OPS connector Gray wire. Start engine and allow to idle for 20
seconds. Increase engine speed to 1600 RPM. If chime sounds, repair
open ground circuit between OPS connector and ground. If chime does
not sound, go to next step.
5) Turn ignition on. Using scan tool, actuate chime. If chime
does not sound, replace Central Timer Module (CTM). CTM is located
under left side of instrument panel. If chime sounds, go to next step.
6) Remove instrument cluster. See appropriate INSTRUMENT
PANELS article. Disconnect CTM 14-pin Green connector C1. Using an
external ohmmeter, measure resistance of Dark Blue/Red wire between
CTM 14-pin Green connector C1 terminal No. 2 and instrument cluster
10-pin connector C2 terminal No. 7. If resistance is less than 5 ohms,
replace CTM. If resistance is 5 ohms or more, repair open Dark
Blue/Red wire.
CHIME SOUNDS WITH DRIVER DOOR OPEN
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting any module connector.
1) Ensure all interior and exterior lights are off. Remove
ignition key and open driver's door. If chime does not sound, system
is currently functioning correctly. If chime sounds, go to next step.
2) Using scan tool, read key-in ignition chime state. If scan
tool displays KEY-IN IGNITION CHIME STATE: "ON/OFF", go to next step.
If scan tool does not display KEY-IN IGNITION CHIME STATE: "ON/OFF",
replace Central Timer Module (CTM). CTM is located under left side of
instrument panel.
3) Disconnect key-in ignition switch connector. See Fig. 1.
Using scan tool, read key-in ignition chime state. If scan tool
displays KEY-IN IGNITION CHIME STATE: ON, go to next step. If scan
tool does not display KEY-IN IGNITION CHIME STATE: ON, replace
ignition switch. See appropriate STEERING COLUMN SWITCHES article.
4) Turn ignition off. Disconnect Central Timer Module (CTM).\
CTM is located under left side of instrument panel. Remove ignition
key. Ensure all lights and accessories are off. Close all doors. Using
external ohmmeter, measure resistance between ground and terminal No.
9 (Light Blue wire) on CTM Green connector "A". If resistance is less
than 10 ohms, repair Light Blue wire between CTM and ignition switch
for short to ground. If resistance is 10 ohms or more, replace CTM.
DOOR AJAR SYSTEM

is to be serviced, slowly loosen inlet side of fuel fill tube fitting
at check valve. It is normal for approximately 25 psi of residual
natural gas pressure to flow from loosened fitting. At this point, all
fuel tubes are purged of natural gas between fuel cylinders and
engine. It is now okay to open fuel system.
WARNING: Fuel cylinders still contain high-pressure fuel.
Compressed Natural Gas Fuel Cylinder Purging (5.2L)
1) Open manual shutoff valve. Open only fuel control valve(s)\
(counterclockwise) on fuel cylinder(s) to be serviced. Close all oth\
er
control valve(s) (clockwise) on fuel cylinder(s) not being service\
d.
2) Start and operate engine until it runs out of fuel.
Attempt 3 more engine starts. At this point, all fuel tubes and opened
cylinders are purged of natural gas between fuel cylinders and engine.
It is now okay to open fuel system.
WARNING: Fuel cylinders not being serviced still contain high-pressure
fuel.
FUEL LINE DISCONNECT FITTINGS
Removal & Installation (Tab Type Fitting)
1) Release fuel pressure. See FUEL PRESSURE RELEASE.
Disconnect negative battery cable. Ensure area around fuel line and
disconnect fitting is clean. Place shop towel around fuel line.
2) On 2-tab connectors, squeeze retainer tabs together and
pull fuel tube/quick-connect fitting assembly off of fuel tube nipple.
On single-tab connectors, use screwdriver to pry up pull tab. See
Fig. 1 . Raise pull tab until it separates from quick-connect fitting.
Discard old pull tab. Disconnect quick-connect fitting from fuel line.
CAUTION: DO NOT install a quick-connect fitting without retainer being
either in fuel tube or already in quick-connect fitting.
After installing fuel line in disconnect fitting, pull on
fuel line and disconnect fitting to ensure fuel line is
locked in place.
3) To install, coat fuel tube nipple with clean 30W engine
oil. Insert quick-connect fitting into fuel tube until stop on fuel
tube rests against back of quick-connect fitting.
4) On single-tab connectors, obtain NEW pull tab. Push tab
down until it locks into quick-connect fitting. On 2-tab connectors,
firmly pull on fuel tube and fitting to ensure retainer and quick-
connect fitting are locked.
Removal & Installation (Retainer Type Fitting)
1) Release fuel pressure. See FUEL PRESSURE RELEASE.
Disconnect negative battery cable. Ensure area around fuel line and
disconnect fitting is clean. Place shop towel around fuel line.
2) Pull backward on disconnect fitting while depressing
plastic ring into disconnect fitting. See Fig. 2. Separate fuel line
from disconnect fitting.
NOTE: Plastic retainer ring must be pressed squarely into fitting
body. If retainer is cocked during removal, it may be
difficult to disconnect fitting. Use open-end wrench on
shoulder of plastic retainer to ease disconnection.
3) To install, ensure plastic ring is in outward position
(away from disconnect fitting). If plastic ring is in inward position
(toward disconnect fitting), disconnect fitting must be replaced.
4) Lubricate end of fuel line with 30W engine oil. Insert

FITTINGS. Remove air cleaner, throttle body, drive belts, generator,
fan and fan pulley. Remove lower fan shroud.
CAUTION: When removing engine, DO NOT lift engine by intake manifold.
5) Remove intake manifold. See INTAKE MANIFOLD. Raise and
support vehicle. Remove starter. Remove exhaust pipe and heat shields.
Disconnect transmission shift linkage. Remove crank sensor.
6) On A/T models, remove transmission inspection cover. Mark
torque converter-to-flexplate position for installation reference.
Remove torque converter-to-flexplate bolts. On M/T models, disconnect
clutch release mechanism at clutch housing.
7) Attach engine hoist to cylinder heads (at intake manifold
flanges). On all models, support transmission using a floor jack.
Remove transmission or clutch housing-to-cylinder block bolts. Remove
engine mount bolts. Remove engine out front of vehicle.
Installation
To install, reverse removal procedure. Tighten bolts/nuts to
specification. See TORQUE SPECIFICATIONS table. On A/T models, ensure
reference marks on torque converter and flexplate are aligned.
Evacuate and charge A/C system.
Removal ( Dakota 2WD, Durango 2WD, Grand Cherokee & Ram
Pickup)
1) Release fuel pressure. See FUEL PRESSURE RELEASE.
Disconnect and remove battery. On all except Pickup, scribe hood
hinges for installation reference and remove hood.
2) On all models, drain cooling system. Disconnect coolant
hoses. Remove radiator, fan and shroud. Discharge A/C system (if
equipped) using approved refrigerant recovery/recycling equipment.
Disconnect A/C lines, and plug openings. On Pickup, remove upper core
support, transmission cooler and A/C condenser. On all models, remove
belt, air cleaner, vacuum lines, distributor cap and wiring.
3) Disconnect necessary electrical wiring. Disconnect fuel
lines. See FUEL LINE DISCONNECT FITTINGS. Remove throttle body and
linkage. Remove intake manifold. Remove starter, generator, charcoal
canister and horns. Disconnect power steering hoses (if equipped).
Raise and support vehicle. Drain oil. Disconnect exhaust pipe at
exhaust manifold.
4) On A/T models, remove transmission housing inspection
plate. Mark torque converter-to-flexplate position for installation
reference. Remove torque converter-to-flexplate bolts. Remove bracket
for transmission cooler lines.
NOTE: It may be necessary to remove manual transmission if
transmission cannot be supported using floor jack.
5) On M/T models, disconnect clutch release mechanism at
clutch housing. On all models, support transmission using a floor
jack. Remove transmission or clutch housing-to-cylinder block bolts.
Install engine lifting fixture, and attach chain.
CAUTION: When removing engine, DO NOT lift engine by intake manifold.
6) On Ram Pickup and Grand Cherokee, remove front engine
mount bolts. Remove engine from vehicle. On Dakota 2WD and Durango 2WD
models, remove front engine mount through-bolts. See Fig. 3. Remove
engine from vehicle.
Installation
To install, reverse removal procedure. Tighten bolts/nuts to
specification. See TORQUE SPECIFICATIONS table. On A/T models, ensure

CYLINDER HEAD
Cylinder Head
Check cylinder head warpage. Repair or replace cylinder head
if warpage exceeds specification. See CYLINDER HEAD table under ENGINE
SPECIFICATIONS.
Valve Springs
1) Check valve spring free length, out-of-square and
pressure. Replace valve spring if not within specification. See VALVES
& VALVE SPRINGS table under ENGINE SPECIFICATIONS.
2) Measure valve spring installed height from bottom of
spring seat (cylinder head surface) to bottom of spring retainer. If
spacers are installed, measure from top of spacer.
3) If height exceeds 1.687" (42.86 mm), install a .066" (1.\
58
mm) thick spacer in cylinder head counterbore to obtain correct
installed spring height. See VALVES & VALVE SPRINGS table.
Valve Stem Oil Seals
Cup-type oil seals are used on all valves. Ensure oversize
valve stem oil seals are used when oversize valves are installed. When
installing valves, DO NOT overcompress valve springs, or damage to
valve stem oil seal may result.
NOTE: DO NOT ream valve guides from standard to maximum oversize in
one step. Ream valve guides to oversize in gradual steps so
guides are reamed true in relation to valve seat. After
reaming valve guides, valve seat runout must be checked.
Valve Guides
Check valve stem oil clearance. Ensure valve stem diameter is
within specification. Valve guide must be reamed for valve with
oversize valve stem if oil clearance exceeds specification. See
CYLINDER HEAD table under ENGINE SPECIFICATIONS. Valves are available
with stems of .015" (.38 mm) and .030" (.76 mm) oversize.
Valve Seat
Check valve seat width and runout. Grind valve seat if not
within specification. See CYLINDER HEAD table under ENGINE
SPECIFICATIONS.
Valves
Ensure valve margin, head diameter and stem diameter are
within specification. See VALVES & VALVE SPRINGS table under ENGINE
SPECIFICATIONS. Valves are available with stems of .015" (.38 mm) and
.030" (.76 mm) oversize.
Valve Seat Correction Angles
Use a 15-degree stone to lower valve seat, and a 60-degree
stone to raise valve seat.
VALVE TRAIN
Rocker Arms & Pivots
Remove rocker arms and pivots. Inspect for wear. Replace as
necessary.
NOTE: Cylinder block must be marked to indicate oversize valve
lifters. See SPECIAL ENGINE MARKS.
Valve Lifters
Measure valve lifter diameter and bore diameter in cylinder

2) Ensure journal diameter, taper and out-of-round are within
specification. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table
under ENGINE SPECIFICATIONS. Upper main bearings contain oil holes,
while lower bearings installed in main bearing cap do not.
3) Apply light coat of engine oil to threads before
tightening bolt to specification. See TORQUE SPECIFICATIONS table.
Ensure oil clearance and end play are within specification. See
CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table.
CAUTION: Crankshaft journal grinding should not exceed .012" (.30 mm)
under standard size. DO NOT grind thrust surfaces of No. 3
main bearing. Final paper or cloth polishing after regrind
must be done in same direction as engine rotation.
Thrust Bearing
Thrust bearing is located on No. 3 main bearing. Replace
thrust bearing if crankshaft end play is not within specification. See
CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table under ENGINE
SPECIFICATIONS.
NOTE: Cylinder bore should be measured at room temperature of 70
F
(21C).
Cylinder Block
1) Check cylinder bore, out-of-round and taper. Measure
cylinder bore diameter below top surface of cylinder bore, middle of
bore and bottom of cylinder bore. Bore cylinder block if bore diameter
is not within specification. See CYLINDER BLOCK table under ENGINE
SPECIFICATIONS.
NOTE: Cylinder block is marked to indicate oversize valve lifters.
See SPECIAL ENGINE MARKS.
2) Check valve lifter bore diameter. Check for scoring. If
scoring exists or lifter bore diameter is not within specification,
ream cylinder block bore for next oversize valve lifter. See VALVE
LIFTERS table under ENGINE SPECIFICATIONS.
ENGINE OILING
ENGINE LUBRICATION SYSTEM
System has a rotor-type oil pump and full-flow oil filter.
Oil is forced by pump through a series of oil passages in engine to
provide lubrication to engine components. Oil is supplied to rocker
assembly through hollow push rods. Push rods are fed oil from lifters.
See Fig. 17 .
Crankcase Capacity
On 3.9L, oil capacity with oil filter is 4.0 qts. (3.8L). On
5.2L and 5.9L, oil capacity with oil filter is 5.0 qts. (4.7L).
Oil Pressure
Oil pressure is 6 psi (.4 kg/cm
) at idle and 30-80 psi (2.1-
5.6 kg/cm) at 3000 RPM with engine at normal operating temperature.