Valve DODGE RAM 2001 Service Repair Manual

(4)Verify valve lash adjustment (Refer to 9 -
ENGINE/CYLINDER HEAD/INTAKE/EXHAUST
VALVES & SEATS - STANDARD PROCEDURE).
(5) Install cylinder head cover and reusable gasket
(Fig. 52) (Refer to 9 - ENGINE/CYLINDER HEAD/
CYLINDER HEAD COVER(S) - INSTALLATION).
(6) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(7) Connect battery negative cables.
ROCKER ARM / ADJUSTER
ASSY
DESCRIPTION
The 24±valve overhead system incorporates rocker
arms that are designed to allow fuel injector service
without removing the rocker arms and pedestals. The
unique intake and exhaust rocker arms have their
own rocker shafts and are lubricated by passages
intersecting the cylinder block main oil rifle. Cross-
heads are used (Fig. 58), which allow each rocker
arm to operate two valves.
The solid push rods are hardened at the rocker
arm and tappet contact areas for superior strength
and durability.
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove cylinder head cover (Fig. 59) (Refer to
9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(3) Remove the rocker arm/pedestal fasteners (Fig.
60) and remove rocker arm and pedestal from cylin-
der head. Mark the arms and pedestals so they can
be installed in their original position.
CAUTION: When removing the rocker arms, the
sockets (Fig. 61) may come loose and fall into the
engine. Make sure they stay with the arm upon
removal/installation.
(4) Lift the push rod(s) up and out of the engine
(Fig. 62). Mark them so they can be installed in their
original position.
NOTE: The #5 cyl. exhaust and #6 cyl. intake and
exhaust push rods must be raised through the pro-
vided cowl panel access holes.
(5) Lift the crosshead(s) off of the valve stems.
Mark them so they can be installed in their original
position.
Fig. 58 Overhead System Components
1 - EXHAUST ROCKER ARM
2 - INTAKE ROCKER ARM
3 - ROCKER SHAFT
4 - SOCKET
5 - ADJUSTING SCREW LOCK NUT
6 - PUSH ROD
7 - PEDESTAL
8 - CROSSHEAD
Fig. 59 Cylinder Head CoverÐRemoval/Installation
1 - BOLT (5)
2 - GASKET
3 - ªTOP FRONTº
4 - ISOLATOR (5)
BR/BEENGINE 5.9L DIESEL 9 - 261
INTAKE/EXHAUST VALVES & SEATS (Continued)

Push Rods
Inspect the push rod ball and socket for signs of
scoring. Check for cracks where the ball and the
socket are pressed into the tube (Fig. 65).
Roll the push rod on a flat work surface with the
socket end hanging off the edge (Fig. 66). Replace
any push rod that appears to be bent.
Crossheads
Inspect the crossheads for cracks and/or excessive
wear on rocker lever and valve tip mating surfaces
(Fig. 67).
INSTALLATION
(1) If previously removed, install the push rods in
their original location.Verify that they are seated
in the tappets.
(2) Lubricate the valve tips and install the cross-
heads in their original locations.
(3) Lubricate the crossheads and push rod sockets
and install the rocker arms and pedestals (Fig. 60) intheir original locations. Tighten bolts to 36 N´m (27
ft. lbs.) torque.
(4)Verify valve lash adjustment (Refer to 9 -
ENGINE/CYLINDER HEAD/INTAKE/EXHAUST
VALVES & SEATS - STANDARD PROCEDURE).
(5) Install cylinder head cover and reusable gasket
(Fig. 59) (Refer to 9 - ENGINE/CYLINDER HEAD/
CYLINDER HEAD COVER(S) - INSTALLATION).
(6) Connect battery negative cables.
ENGINE BLOCK
STANDARD PROCEDURE-CYLINDER BLOCK
REFACING
(1) The combustion deck can be refaced twice. The
first reface should be 0.25 mm (0.0098 inch). If addi-
tional refacing is required, an additional 0.25 mm
(0.0098 inch) can be removed. Total allowed refacing
is 0.50 mm (0.0197 inch) - (Fig. 68).
Fig. 64 Measuring Rocker Arm Shaft
ROCKER ARM SHAFT (MIN.)
21.965 mm (.865 in.)
Fig. 65 Inspecting Push Rod for Cracks
Fig. 66 Inspecting Push Rod for Flatness
Fig. 67 Inspecting Crosshead for Cracks
BR/BEENGINE 5.9L DIESEL 9 - 263
ROCKER ARM / ADJUSTER ASSY (Continued)

(2) The upper right corner of the rear face of the
block must be stamped with a X when the block is
refaced to 0.25 mm (0.0098 inch). A second X must be
stamped beside the first when the block is refaced to
0.50 mm (0.0197 inch) - (Fig. 69).
(3) Consult the parts catalog for the proper head
gaskets which must be used with refaced blocks to
ensure proper piston-to-valve clearance.
STANDARD PROCEDURE-CYLINDER BORE -
DE-GLAZE
(1) New piston rings may not seat in glazed cylin-
der bores.
(2) De-glazing gives the bore the correct surface
finish required to seat the rings. The size of the bore
is not changed by proper de-glazing.
(3) Cover the lube holes in the top of the block
with waterproof tape.
(4) A correctly honed surface will have a cross-
hatch appearance with the lines at 15É to 25É angles
(Fig. 70). For the rough hone, use 80 grit honing
stones. To finish hone, use 280 grit honing stones.
(5) Use a drill, a fine grit Flex-hone and a mixture
of equal parts of mineral spirits and SAE 30W engine
oil to de-glaze the bores.
(6)
The crosshatch angle is a function of drill speed
and how fast the hone is moved vertically (Fig. 71).
(7) Vertical strokes MUST be smooth continuous
passes along the full length of the bore (Fig. 71).
(8) Inspect the bore after 10 strokes.
(9) Use a strong solution of hot water and laundry
detergent to clean the bores. Clean the cylinder bores
immediately after de-glazing.
(10) Rinse the bores until the detergent is removed
and blow the block dry with compressed air.
Fig. 68 Refacing Dimensions of the Cylinder Block
CYLINDER BLOCK REFACING DIMENSIONS
DIMENSION(A(
1st Reface 0.25mm (0.0098 in.)
2nd Reface 0.25mm (0.0098 in.)
Dim (A) Total 0.50 mm (0.0197 in.)
DIMENSION(B(
Dim.9B9(STD.)323.00 mm  
0.10 mm(12.7165 in.  
0.0039 in.)
1st Reface322.75 mm  
0.10 mm(12.7067 in.  
0.0039 in.)
2nd Reface322.50 mm  
0.10 mm(12.6968 in.  
0.0039 in.)
Fig. 69 Stamp Block after Reface
Fig. 70 Cylinder Bore Crosshatch Pattern
Fig. 71 De-Glazing Drill Speed and Vertical Speed
9 - 264 ENGINE 5.9L DIESELBR/BE
ENGINE BLOCK (Continued)

(29)Remove the camshaft (Fig. 91) and thrust plate.
INSPECTION
Camshaft
(1)Inspect the valve lobes and bearing journals for
cracks, pitting, scoring, or generally excessive wear.
Replace any camshaft that exceeds the allowable limits.
(2)Measure the bearing journals and lobes (Fig. 92).
CAUTION: If Camshaft lobes are worn, requiring
camshaft replacement, it is necessary to replace the
tappets also. (Refer to 9 - ENGINE/ENGINE BLOCK/
SOLID LIFTERS - REMOVAL).
Camshaft Bushing/Bores
Camshaft bores No. 2±7do notuse a bushing.
(1) Inspect the camshaft bushing and bores for
signs of excessive wear.
(2) Measure the camshaft bushing and bores (Fig.
93) with a telescoping bore gauge and micrometer. If
out of specification, (Refer to 9 - ENGINE/ENGINE
BLOCK/CAMSHAFT & BEARINGS (IN BLOCK) -
REMOVAL).
(3) Inspect the camshaft bushing oil hole for align-
ment with cylinder block (Fig. 94).
Fig. 92 Measuring
1 - VALVE LOBE
2 - CAMSHAFT JOURNAL
JOURNAL DIAMETER #1 54.028 mm (2.1270 in.) MIN.
JOURNAL DIAMETER #2 - 7 53.987 mm (2.1245 in.) MIN.
LOBE HEIGHT INTAKE 47.173 mm (1.857 in.) MIN.
LOBE HEIGHT EXHAUST 45.636 mm (1.796 in.) MIN.
Fig. 91 Camshaft Removal/Installation
Fig. 93 Measuring Camshaft Bushing and Bores
Fig. 94 Inspecting Oil Hole Alignment
1 - CAMSHAFT BUSHING
9 - 272 ENGINE 5.9L DIESELBR/BE
CAMSHAFT & BEARINGS (IN BLOCK) (Continued)

Camshaft Gear
Inspect the camshaft gear for cracks (gear and
hub) (Fig. 95), and chipped/broken/fretted teeth (Fig.
96). If replacement is necessary, (Refer to 9 -
ENGINE/ENGINE BLOCK/CAMSHAFT & BEAR-
INGS (IN BLOCK) - REMOVAL).
Thrust Plate
Inspect the camshaft thrust plate for excessive
wear in the camshaft contact area. Measure thrust
plate thickness using the CAMSHAFT THRUST
PLATE THICKNESS CHART. Replace any thrust
plate that falls outside of these specifications:
CAMSHAFT THRUST PLATE THICKNESS
CHART
9.34 mm (0.368 in.) MIN.
9.58 mm (0.377 in.) MAX.
INSTALLATIONÐCAMSHAFT BEARINGS
(1) Apply a coating of Loctitet640 Adhesive to the
backside of the new bushing. Avoid getting adhesive
in the oil hole.
(2) Use a universal cam bushing installation tool
and install the bushing so that it is even with the
front face of the cylinder block. The oil hole must be
aligned. A 3.2 mm (0.128 inch) diameter rod must be
able to pass through the hole (Fig. 97).
(3) Measure the installed bushing. The limit of the
inside diameter is 54.133 mm (2.1312 inch).
INSTALLATIONÐCAMSHAFT
(1) Lubricate the camshaft bushing and bores with
fresh engine oil or suitable equivalent.
(2) Liberally coat the camshaft lobes, journals, and
thrust washer with fresh engine oil or suitable equiv-
alent.
CAUTION: When installing the camshaft (Fig. 91),
DO NOT push it in farther than it will go with the
thrust washer in place. Pushing it too far can dis-
lodge the plug in the rear of the camshaft bore and
cause an oil leak.
(3) Install the camshaft (Fig. 91) and thrust plate.
Align the timing marks as shown in (Fig. 89).
(4) Install the thrust plate bolts and tighten to 24
N´m (18 ft. lbs.) torque.
(5) Measure camshaft back lash and end clearance
(Fig. 98).
(6) Remove the wooden dowel rods and rubber
bands from the tappets.
(7) Lubricate the push rods with engine oil and
install in their original location (Fig. 87).Verify that
they are seated in the tappets.
(8) Lubricate the valve tips with engine oil and
install the crossheads in their original locations.
(9) Lubricate the crossheads and push rod sockets
with engine oil and install the rocker arms and ped-
estals in their original locations (Fig. 86). Tighten
bolts to 36 N´m (27 ft. lbs.) torque.
Fig. 95 Inspect Camshaft Gear Hub for Cracks
Fig. 96 Inspect Camshaft Gear for Cracks and
Fretting
Fig. 97 Oil Hole Alignment
1 - CAMSHAFT BUSHING
BR/BEENGINE 5.9L DIESEL 9 - 273
CAMSHAFT & BEARINGS (IN BLOCK) (Continued)

(10)Verify valve lash adjustment (Refer to 9 -
ENGINE/CYLINDER HEAD/INTAKE/EXHAUST
VALVES & SEATS - STANDARD PROCEDURE).
(11)
Install the cylinder head cover and reusable gas-
ket (Fig. 85) (Refer to 9 - ENGINE/CYLINDER HEAD/
CYLINDER HEAD COVER(S) - INSTALLATION).
(12) Install gear housing cover (Refer to 9 -
ENGINE/VALVE TIMING/GEAR HOUSING COVER
- INSTALLATION).
(13) Install the crankshaft damper (Fig. 83) (Refer
to 9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - INSTALLATION).
(14) Install the fan support/hub assembly (Fig. 82)
and tighten bolts to 24 N´m (18 ft. lbs.) torque.
(15) Install the crankcase breather housing (Refer
to 9 - ENGINE - INSTALLATION).
(16) Install the charge air cooler (with a/c con-
denser and auxiliary transmission oil cooler, if
equipped) and tighten the mounting bolts to 2 N´m
(17 in. lbs.) torque.
(17) Connect charge air cooler inlet and outlet
pipes. Tighten clamps to 10 N´m (100 in. lbs.) torque.
(18) Install the radiator upper support panel.
(19) Close radiator petcock and lower the radiator
into the engine compartment. Tighten the mounting
bolts to 11 N´m (95 in. lbs.) torque.
(20) Raise vehicle on hoist.
(21)
Connect radiator lower hose and install clamp.
(22) Connect transmission auxiliary oil cooler lines
(if equipped).
(23) Lower vehicle.
(24) Install the fan shroud and tighten the mount-
ing screws to 6 N´m (50 in. lbs.) torque.(25) Install the viscous fan/drive assembly (Refer
to 7 - COOLING/ENGINE/RADIATOR FAN -
INSTALLATION).
(26) Install the coolant recovery and windshield
washer fluid reservoirs to the fan shroud.
(27) Connect the coolant recovery hose to the radi-
ator filler neck.
(28) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(29) Install the front bumper assembly (Refer to 13
- FRAMES & BUMPERS/BUMPERS/FRONT
BUMPER - INSTALLATION).
(30) Add engine coolant (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(31) Charge A/C system with refrigerant (if A/C
equipped) (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE).
(32) Connect the battery negative cables.
(33) Start engine and check for engine oil and cool-
ant leaks.
CONNECTING ROD BEARINGS
STANDARD PROCEDUREÐCONNECTING ROD
BEARING AND CRANKSHAFT JOURNAL
CLEARANCE
Measure the connecting rod bore with the bearings
installed and the bolts tightened to 100 N´m (73 ft.
lbs.) torque.
Record the smaller diameter.
Measure the diameter of the rod journal at the
location shown (Fig. 99). Calculate the average diam-
eter for each side of the journal.
The clearance is the difference between the con-
necting rod bore (smallest diameter) and the average
diameter for each side of the crankshaft journal.
CONNECTING ROD JOURNAL DIAMETER
LIMITS CHART
DESCRIPTION MEASUREMENT
CRANKSHAFT ROD
JOURNAL DIAMETERMINIMUM 68.962 mm
(2.715 in.)
MAXIMUM 69.013 mm
(2.717 in.)
OUT-OF-ROUND MAXIMUM 0.050 mm
(0.002 in.)
TAPER MAXIMUM 0.013 mm
(0.0005 in.)
BEARING CLEARANCE MAXIMUM 0.089 mm
(0.0035 in.)
Fig. 98 Camshaft Backlash and End Clearance
1 - CAMSHAFT GEAR
2 - CAMSHAFT GEAR BACKLASH
3 - CAMSHAFT GEAR CLEARANCE
BACKLASH Ð 0.152Ð0.33 mm
(0.006Ð0.013 inch)
CLEARANCE Ð 0.1Ð0.46 mm
(0.004Ð0.0182 inch)
9 - 274 ENGINE 5.9L DIESELBR/BE
CAMSHAFT & BEARINGS (IN BLOCK) (Continued)

LUBRICATION
DESCRIPTION
NOTE: Refer to (Fig. 148) and (Fig. 149) for circuit
illustrations.
A gear driven gerotor type oil pump is mounted
behind the front gear cover in the lower right portion
on the engine.
OPERATION
A gerotor style oil pump draws oil from the crank-
case through the suction tube and delivers it through
the block where it enters the oil cooler cover and
pressure regulator valve. When oil pressure exceeds
449 kPa (65 PSI), the valve opens exposing the dump
port, which routes excess oil back to the oil sump.
At the same time, oil is directed to a cast in pas-
sage in the oil cooler cover, leading to the oil cooler
element. As the oil travels through the element
plates, it is cooled by engine coolant traveling past
the outside of the plates. It is then routed to the oil
filter head and through a full flow oil filter. If a
plugged filter is encountered, the filter by-pass valve
opens, allowing unfiltered oil to lubricate the engine.
This condition can be avoided by frequent oil and fil-
ter changes, per the maintenance schedules found in
the owners manual. The by-pass valve is calibrated
to open when it sees a pressure drop of more than
344 kPa (50 psi) across the oil filter.The oil filter head then divides the oil between the
engine and the turbocharger. The turbocharger
receives filtered, cooled and pressurized oil through a
supply line from the filter head. The oil lubricates
the turbocharger and returns to the pan by way of a
drain tube connecting the bottom of the turbocharger
to a pressed in tube in the cylinder block.
Oil is then carried across the block to an angle
drilling which intersects the main oil rifle. The main
oil rifle runs the length of the block and delivers oil
to the crankshaft main journals and valve train. Oil
travels to the crankshaft through a series of transfer
drillings (one for each main bearing) and lubricates a
groove in the main bearing upper shell. From there
another drilling feeds the camshaft main journals.
The piston cooling nozzles are also supplied by the
main bearing upper shell. Crankshaft internal cross-
drillings supply oil to the connecting rod journals.
Another series of transfer drillings intersecting the
main oil rifle supply the valve train components. Oil
travels up the drilling, through a hole in the head
gasket, and through a drilling in the cylinder head
(one per cylinder), where it enters the rocker arm
pedestal and is divided between the intake and
exhaust rocker arm. Oil travels up and around the
rocker arm mounting bolt, and lubricates the rocker
shaft by cross drillings that intersect the mounting
bolt hole. Grooves at both ends of the rocker shaft
supply oil through the rocker arm where the oil trav-
els to the push rod and socket balls (Fig. 148) and
(Fig. 149).
9 - 292 ENGINE 5.9L DIESELBR/BE

DIAGNOSIS AND TESTINGÐENGINE OIL
PRESSURE
(1) Remove the engine oil pressure sensor and
install Oil Pressure Line and Gauge Tool C-3292 with
a suitable adapter.
(2) Start engine and warm to operating tempera-
ture.
(3) Record engine oil pressure and compare with
engine oil pressure chart.
CAUTION: If engine oil pressure is zero at idle, DO
NOT RUN THE ENGINE.
Engine Oil Pressure (MIN)
At Idle 103.4 kPa (15 psi)
At 2000 rpm 310.2 kPa (45 psi)
If minimum engine oil pressure is below these
ranges, (Refer to 9 - ENGINE - DIAGNOSIS AND
TESTING).
(4) Remove oil pressure gauge and install the oil
pressure sensor. Tighten the sensor to 16 N´m (144
in. lbs.) torque.
OIL
STANDARD PROCEDURE-ENGINE OIL LEVEL
CAUTION: Do not overfill crankcase with engine oil,
oil foaming and oil pressure loss can result.
To ensure proper lubrication of an engine, the
engine oil must be maintained at an acceptable level.
The acceptable oil level is in the SAFE RANGE on
the engine oil dipstick (Fig. 150).
Unless the engine has exhibited loss of oil pres-
sure, run the engine for about five minutes before
checking oil level. Checking engine oil level of a cold
engine is not accurate.
(1) Position vehicle on level surface.
(2) With engine OFF, allow approximately ten min-
utes for oil to settle to bottom of crankcase, remove
engine oil dipstick.
(3) Wipe dipstick clean.(4)
Replace dipstick and verify it is seated in the
tube.
(5) Remove dipstick, with handle held above the
tip, take oil level reading.
(6) Add oil only if level is below the SAFE RANGE
area on the dipstick.
(7) Replace dipstick
STANDARD PROCEDURE-ENGINE OIL SERVICE
WARNING: HOT OIL CAN CAUSE PERSONAL
INJURY.
NOTE: Change engine oil and filter at intervals
specified in the owner's manual.
(1) Operate the engine until the water tempera-
ture reaches 60ÉC (140ÉF). Shut the engine off.
(2) Use a container that can hold at least 14 liters
(15 quarts) to hold the used oil. Remove the oil drain
plug and drain the used engine oil into the container.
(3) Always check the condition of the used oil. This
can give you an indication of engine problems that
might exist.
²Thin, black oil indicates fuel dilution.
1 - ROCKER ARM
2 - ROCKER SHAFT
3 - PEDESTAL
4 - FROM MAIN OIL RIFLE
5 - TO VALVE TRAIN
6 - MAIN OIL RIFLE
7 - FROM MAIN OIL RIFLE
8 - TO CAMSHAFT9 - TO PISTON COOLING NOZZLE
10 - FROM OIL COOLER
11 - CRANKSHAFT MAIN JOURNAL
12 - ROD JOURNAL
13 - TO ROD BEARING
14 - MAIN OIL RIFLE
Fig. 150 Oil Level Indicator (Dipstick)
1 - ADD OIL MARK
2 - O-RING
3 - SAFE RANGE
BR/BEENGINE 5.9L DIESEL 9 - 295
LUBRICATION (Continued)

CLEANING
Remove all gasket material from the oil pan and
cylinder block sealing surfaces. Extra effort may be
required around T-joint areas. Clean oil pan and
flush suction tube with a suitable solvent.
INSPECTION
Inspect the oil pan, suction tube, and tube braces
for cracks and damage. Replace any defective compo-
nent. Inspect the oil drain plug and drain hole
threads. Inspect the oil pan sealing surface for
straightness. Repair any minor imperfections with a
ball-peen hammer. Do not attempt to repair an oil
pan by welding.
INSTALLATION
(1) Fill the T-joint between the pan rail/gear hous-
ing and pan rail/rear seal retainer with sealant. Use
MopartSilicone Rubber Adhesive Sealant or equiva-
lent.
(2) Place suction tube in oil pan and guide them
into place (Fig. 151). Using a new tube to oil pump
gasket, install and tighten the suction tube bolts by
hand. Starting with the oil pump inlet bolts, tighten
the bolts to 24 N´m (18 ft. lbs.) torque. Tighten the
remaining tube brace bolts to 24 N´m (18 ft. lbs.)
torque.
(3) Starting in the center and working outward,
tighten the oil pan bolts to 24 N´m (18 ft. lbs.)
torque.
(4) Install the flywheel housing assembly with the
starter motor attached and tighten bolts to 60 N´m
(44 ft. lbs.) torque.
(5) Connect starter motor cables.
(6) Install transmission and transfer case (if
equipped).
(7) Lower vehicle.
(8) Install battery negative cables.
(9) Fill the crankcase with new engine oil.
(10) Start engine and check for leaks. Stop engine,
check oil level, and adjust, if necessary.
OIL PRESSURE RELIEF VALVE
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove the threaded plug, spring and plunger
(Fig. 152). Insert a finger or a seal pick to lift the
plunger from the bore.
NOTE: If the plunger is stuck in the bore, it will be
necessary to remove the filter head.
CLEANING
(1) Clean the regulator spring and plunger with a
suitable solvent and blow dry with compressed air. If
the plunger bore requires cleaning, it is necessary to
remove the oil filter head to avoid getting debris into
the engine.
INSPECTION
Inspect the plunger and plunger bore for cracks
and excessive wear. Polished surfaces are acceptable.
Verify that the plunger moves freely in the bore.
Check the spring for height and load limitations
(Fig. 153). Replace the spring if out of limits shown
in the figure.
Fig. 152 Oil Pressure Regulator
1 - OIL FILTER
2 - PLUG
3 - GASKET
4 - SPRING
5 - VALVE
Fig. 153 Oil Pressure Regulator Spring Check
BR/BEENGINE 5.9L DIESEL 9 - 297
OIL PAN (Continued)

INSTALLATION
(1) Install the plunger, spring, and plug as shown
in (Fig. 152). Tighten the plug to 80 N´m (60 ft. lbs.)
torque.
(2) Connect the battery negative cables.
(3) Start the engine and verify that it has oil pres-
sure.
OIL PRESSURE SENSOR/
SWITCH
DESCRIPTION
The 3±wire, solid-state oil pressure sensor is
installed into the oil pressure galley on the engine
block. It is located below and to the rear of the
Engine Control Module (ECM) (Fig. 154).
OPERATION
Operation of the oil pressure sensor on the
diesel engine is controlled by the Engine Con-
trol Module (ECM). The Powertrain Control
Module (PCM) does not have any control over
the sensor.The oil pressure sensor uses three circuits. They
are:
²A 5±volt power supply from the ECM
²A sensor ground through the ECM's sensor
return
²A signal to the ECM relating to engine oil pres-
sure
The oil pressure sensor has a 3±wire electrical
function very much like the Manifold Absolute Pres-
sure (MAP) sensor on the gasoline powered engine.
Meaning different pressures relate to different output
voltages.
A 5±volt supply is sent to the sensor from the ECM
to power up the sensor. The sensor returns a voltage
signal back to the ECM relating to engine oil pres-
sure. This signal is then transferred (bussed) to the
instrument panel on the CCD bus circuit to operate
the oil pressure gauge and the check gauges lamp.
Ground for the sensor is provided by the ECM
through a low-noise sensor return.
REMOVAL
(1) Disconnect the battery negative cables.
(2) Disconnect the oil pressure sensor connector
(Fig. 155).
(3) Using a suitable socket, remove the oil pres-
sure sensor from the block (counter-clockwise).
Fig. 154 Oil Pressure Sensor (Engine) Location
1 - ENGINE OIL PRESSURE SENSOR
2 - ELECTRIAL CONNECTOR
3 - ECM
Fig. 155 Oil Pressure Sensor Location
1 - ENGINE OIL PRESSURE SENSOR
2 - ELECTRIAL CONNECTOR
3 - ECM
9 - 298 ENGINE 5.9L DIESELBR/BE
OIL PRESSURE RELIEF VALVE (Continued)