1998 DODGE RAM 1500 Crankshaft position sensor

INSTALLATION
Engine Mounted Sensor :
The APPS is serviced (replaced) as one assembly
including the lever, brackets and sensor. The APPS is
calibrated to its mounting bracket.
(1) Snap electrical connector into bottom of sensor.
(2) Position APPS assembly to engine and install 6
bolts. Tighten bolts to 24 N´m (18 ft. lbs.) torque.
(3) Connect wiring harness clip at bottom of
bracket.
(4) Refer to Group 21, Transmission for transmis-
sion control cable installation procedures.
(5) Install speed control cable into mounting
bracket. Be sure pinch tabs have secured cable.
(6) Install throttle cable into mounting bracket. Be
sure pinch tabs have secured cable.
(7) Connect throttle cable at lever (snaps on).
(8) Connect speed control cable to lever by pushing
cable connector rearward onto lever pin while hold-
ing lever forward.
(9) Install cable cover.
(10) Connect both negative battery cables to both
batteries.
(11) If necessary, use DRB IIItScan Tool to erase
any Diagnostic Trouble Codes (DTC's) from ECM.Battery Tray Mounted Sensor :
(1) Install Accelerator Pedal Position Sensor
(APPS) cable to accelerator pedal. Refer to Accelera-
tor Pedal Removal / Installation.
(2) Connect electrical connector to APPS.
(3) If necessary, connect cable to APPS lever ball
socket (snaps on).
(4) Snap APPS cable cover closed.
(5) Position APPS assembly to bottom of battery
tray and install 3 bolts. Refer to Torque Specifica-
tions.
(6) Install wheelhouse liner. Refer to Body.
(7) Perform the following procedure:
(a) Connect negative battery cables to both bat-
teries.
(b) Turn key switch ON, but do not crank
engine.
(c) Leave key switch ON for a minimum of 10
seconds. This will allow ECM to learn electrical
parameters.
(8) If necessary, use DRB IIItScan Tool to erase
any Diagnostic Trouble Codes (DTC's) from ECM.
CAMSHAFT POSITION
SENSOR
DESCRIPTION
The Camshaft Position Sensor (CMP) on the 5.9L
diesel engine is located below the fuel injection
pump. It is bolted to the back of the timing gear
housing.
OPERATION
The diesel Camshaft Position Sensor (CMP) con-
tains a hall effect device. A rotating target wheel
(tonewheel) for the CMP is located on the camshaft
gear. This hall effect device detects notches located
on the back side of the camshaft gear. As the cam-
shaft gear rotates, the notches pass the tip of the
CMP.
When the leading edge of the notch passes the tip
of the CMP, the following occurs: The interruption of
magnetic field causes the voltage to switch high
resulting in a signal of approximately 5 volts.
When the trailing edge of the notch passes the tip
of the CMP, the following occurs: The change of the
magnetic field causes the signal voltage to switch low
to 0 volts.
The CMP (Fig. 8) provides a signal to the Engine
Control Module (ECM) at all times when the engine
is running. The ECM uses the CMP information pri-
marily on engine start-up. Once the engine is run-
ning, the ECM uses the CMP as a backup sensor for
engine speed. The Crankshaft Position Sensor (CKP)
Fig. 7 APPS CABLE (OFF ENGINE MOUNTING)
1 - APPS LEVER
2 - BALL SOCKET
3 - SWING-DOWN DOOR
4 - CABLE CLIP
5 - CABLE
DRFUEL INJECTION - DIESEL 14 - 71
ACCELERATOR PEDAL POSITION SENSOR (Continued)

is the primary engine speed indicator for the engine
after the engine is running.
REMOVAL
The Camshaft Position Sensor (CMP) on the 5.9L
diesel engine is located below the fuel injection
pump. It is bolted to the back of the timing gear
housing (Fig. 9).
(1) Disconnect electrical connector at CMP sensor
(Fig. 9).
(2) Remove sensor mounting bolt.
(3) Carefully twist sensor from timing gear hous-
ing.
(4) Check condition of sensor o-ring.
INSTALLATION
(1) Clean out machined hole in back of timing gear
housing (cover).
(2) Apply a small amount of engine oil to sensor
o-ring.
(3) Install sensor into timing gear housing (cover)
with a slight rocking action. Do not twist sensor into
position as damage to o-ring may result.
CAUTION: Before tightening sensor mounting bolt,
be sure sensor is completely flush to back of timingchain housing (cover). If sensor is not flush, dam-
age to sensor mounting tang may result.
(4) Install mounting bolt and tighten. Refer to
Torque Specifications.
(5) Connect electrical connector to sensor.
CRANKSHAFT POSITION
SENSOR
DESCRIPTION
The Crankshaft Position Sensor (CKP) on the die-
sel engine is attached at the front / left side of the
engine next to the engine harmonic balancer (crank-
shaft damper).
OPERATION
The Crankshaft Position Sensor (CKP) is the pri-
mary engine speed indicator for the engine after the
engine is running (Fig. 10). The CKP contains a hall
effect device. A rotating, notched target wheel (tone-
wheel) for the CKP is located on the engine harmonic
balancer (Fig. 11). This hall effect device detects
notches located on the tonewheel. As the tonewheel
rotates, the notches pass the tip of the CKP.
Fig. 8 5.9L DIESEL CMP
1 - CMP
2 - FUEL INJECTION PUMP (BOTTOM)
3 - ELECTRONIC CONTROL MODULE (ECM)
4 - ECM ELEC. CONNECTOR
5 - CMP ELEC. CONNECTOR
6 - CMP MOUNTING BOLT
7 - BACK OF TIMING GEAR HOUSING
Fig. 9 5.9L DIESEL CMP
1 - CMP
2 - FUEL INJECTION PUMP (BOTTOM)
3 - ELECTRONIC CONTROL MODULE (ECM)
4 - ECM ELEC. CONNECTOR
5 - CMP ELEC. CONNECTOR
6 - CMP MOUNTING BOLT
7 - BACK OF TIMING GEAR HOUSING
14 - 72 FUEL INJECTION - DIESELDR
CAMSHAFT POSITION SENSOR (Continued)

When the leading edge of the tonewheel notch
passes the tip of the CKP, the following occurs: The
interruption of magnetic field causes the voltage to
switch high resulting in a signal of approximately 5
volts.
When the trailing edge of the tonewheel notch
passes the tip of the CKP, the following occurs: The
change of the magnetic field causes the signal voltage
to switch low to 0 volts.
The Camshaft Position Sensor (CMP) also provides
a signal to the Engine Control Module (ECM) at all
times when the engine is running. The ECM uses
this CMP information primarily on engine start-up.
Once the engine is running, the ECM uses the CMP
as a backup sensor for engine speed.
REMOVAL
(1) Raise and support vehicle
(2) Disconnect electrical connector at CKP sensor
(Fig. 12).
(3) Remove 1 sensor mounting bolt.
(4) Remove CKP sensor.
INSTALLATION
(1) Position and install CKP sensor to engine.
(2) Install 1 sensor mounting bolt and tighten to 9
N´m (80 in. lbs.) torque.(3) Install electrical connector to CKP sensor (Fig.
12).
Fig. 10 5.9L DIESEL CKP
1 - ENGINE HARMONIC BALANCER
2 - FRONT OF TIMING GEAR COVER
3 - CKP MOUNTING BOLT
4 - ELEC. CONNECTOR
5 - CKP SENSOR
6 - NOTCHES
Fig. 11 CKP NOTCHED TONEWHEEL
1 - ENGINE HARMONIC BALANCER
2 - NOTCHED TONEWHEEL
3 - FRONT OF CRANKSHAFT
Fig. 12 5.9L DIESEL CKP
1 - ENGINE HARMONIC BALANCER
2 - FRONT OF TIMING GEAR COVER
3 - CKP MOUNTING BOLT
4 - ELEC. CONNECTOR
5 - CKP SENSOR
6 - NOTCHES
DRFUEL INJECTION - DIESEL 14 - 73
CRANKSHAFT POSITION SENSOR (Continued)

STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR
Damaged or worn threads in the aluminum trans-
mission case and valve body can be repaired by the
use of Heli-CoilsŸ, or equivalent. This repair con-
sists of drilling out the worn-out damaged threads.
Then tap the hole with a special Heli-CoilŸ tap, or
equivalent, and installing a Heli-CoilŸ insert, or
equivalent, into the hole. This brings the hole back to
its original thread size.
Heli-CoilŸ, or equivalent, tools and inserts are
readily available from most automotive parts suppli-
ers.
REMOVAL
NOTE: The overdrive unit can be removed and ser-
viced separately. It is not necessary to remove the
entire transmission assembly to perform overdrive
unit repairs.
(1) Disconnect battery negative cable.
(2) Raise vehicle.
(3) Remove the transfer case skid plate (Fig. 12), if
equipped.(4) Disconnect and lower or remove necessary
exhaust components.
(5) Remove engine-to-transmission struts.
(6) Remove starter motor. (Refer to 8 - ELECTRI-
CAL/STARTING/STARTER MOTOR - REMOVAL)
(7) Disconnect and remove the crankshaft position
sensor. (Refer to 14 - FUEL SYSTEM/FUEL INJEC-
TION/CRANKSHAFT POSITION SENSOR -
REMOVAL) Retain the sensor attaching bolts.
(8) If transmission is being removed for overhaul,
remove transmission oil pan, drain fluid and reinstall
pan.
(9) Remove torque converter access cover.
(10) Rotate crankshaft in clockwise direction until
converter bolts are accessible. Then remove bolts one
at a time. Rotate crankshaft with socket wrench on
dampener bolt.
(11) Mark propeller shaft and axle yokes for
assembly alignment. Then disconnect and remove
propeller shaft. On4x4models, remove both propel-
ler shafts. (Refer to 3 - DIFFERENTIAL & DRIV-
ELINE/PROPELLER SHAFT/PROPELLER SHAFT -
REMOVAL)
(12) Disconnect wires from the transmission range
sensor and transmission solenoid connector.
(13) Disconnect gearshift cable (Fig. 13) from the
transmission.
Fig. 12 Transfer Case Skid Plate
1 - FRAME RAIL
2 - SKID PLATE
3 - BOLTS (6)
Fig. 13 Gearshift Cable At Transmission
1 - GEARSHIFT CABLE
2 - TRANSMISSION MANUAL LEVER
3 - CABLE SUPPORT BRACKET
21 - 158 AUTOMATIC TRANSMISSION - 48REDR
AUTOMATIC TRANSMISSION - 48RE (Continued)

(9) Install the two screws to hold the TRS to the
mounting bracket. Tighten the screws to 5 N´m (45
in.lbs.).
(10) Verify proper sensor operation (Fig. 62).
(11) Move the transmission manual shaft lever to
the PARK position.
(12) Install torque converter. Use C-clamp or metal
strap to hold converter in place for installation.
BAND ADJUSTMENT AND FINAL
(1) Adjust front and rear bands as follows:
(a) Loosen locknut on each band adjusting screw
4-5 turns.
(b) Tighten both adjusting screws to 8 N´m (72
in. lbs.).
(c) Back off front band adjusting screw 1-3/4
turns.
(d) Back off rear band adjusting screw 3 turns.
(e) Hold each adjusting screw in position and
tighten locknut to 34 N´m (25 ft. lbs.) torque.
(2) Install magnet in oil pan. Magnet seats on
small protrusion at corner of pan.
(3) Position new oil pan gasket on case and install
oil pan. Tighten pan bolts to 13.6 N´m (125 in. lbs.).
(4) Install throttle valve and shift selector levers
on valve body manual lever shaft.
(5) Apply small quantity of dielectric grease to ter-
minal pins of solenoid case connector and neutral
switch.
(6) Fill transmission with recommended fluid.
INSTALLATION
(1) Check torque converter hub inner and outer
diameters and hub drive notches for sharp edgesburrs, scratches, or nicks. Polish the hub and notches
with 320/400 grit paper and crocus cloth if necessary.
The hub must be smooth to avoid damaging pump
seal at installation.
(2) Lubricate pocket in the rear oil pump seal lip
with transmission fluid.
(3) Lubricate converter pilot hub of the crankshaft
with a light coating of MopartHigh Temp Grease.
(4) Align and install converter in oil pump.
(5) Carefully insert converter in oil pump. Then
rotate converter back and forth until fully seated in
pump gears.
(6) Check converter seating with steel scale and
straightedge (Fig. 63). Surface of converter lugs
should be 19mm (0.75 in.) to rear of straightedge
when converter is fully seated.
(7) Temporarily secure converter with C-clamp.
(8) Position transmission on jack and secure it
with chains.
(9) Check condition of converter driveplate.
Replace the plate if cracked, distorted or damaged.
Also be sure transmission dowel pins are seated
in engine block and protrude far enough to
hold transmission in alignment.
(10) Raise transmission and align converter with
drive plate and converter housing with engine block.
(11) Move transmission forward. Then raise, lower
or tilt transmission to align converter housing with
engine block dowels.
(12) Carefully work transmission forward and over
engine block dowels until converter hub is seated in
crankshaft.
Fig. 62 Transmission Range Sensor Operation
1 - NEUTRAL CONTACT
2 - MANUAL LEVER AND SENSOR PLUNGER IN REVERSE
POSITION
3 - PARK CONTACT
4 - TRANSMISSION RANGE SENSOR
Fig. 63 Checking Converter Seating - Typical
1 - SCALE
2 - STRAIGHTEDGE
21 - 174 AUTOMATIC TRANSMISSION - 48REDR
AUTOMATIC TRANSMISSION - 48RE (Continued)

(13) Install bolts attaching converter housing to
engine.
(14) Install rear support.
(15) Install the rear transmission crossmember.
(16) Lower transmission onto crossmember and
install bolts attaching transmission mount to cross-
member.
(17) Remove engine support fixture.
(18) Install the transfer case, if equipped.
(19) Install crankshaft position sensor. (Refer to 14
- FUEL SYSTEM/FUEL INJECTION/CRANKSHAFT
POSITION SENSOR - INSTALLATION)
(20) Connect gearshift cable (Fig. 64) and throttle
cable to transmission.
(21) Connect wires to the transmission range sen-
sor and transmission solenoid connector. Be sure the
transmission harnesses are properly routed.
CAUTION: It is essential that correct length bolts be
used to attach the converter to the driveplate. Bolts
that are too long will damage the clutch surface
inside the converter.(22) Install torque converter-to-driveplate bolts.
(23) Install converter housing access cover.
(24) Install starter motor and cooler line bracket.
(Refer to 8 - ELECTRICAL/STARTING/STARTER
MOTOR - INSTALLATION)
(25) Connect cooler lines (Fig. 65) to transmission.
(26) Install transmission fill tube. Install new seal
on tube before installation.
(27) Install any exhaust components previously
removed.
(28) Align and connect propeller shaft. (Refer to 3 -
DIFFERENTIAL & DRIVELINE/PROPELLER
SHAFT/PROPELLER SHAFT - INSTALLATION)
(29) Adjust gearshift cable and throttle valve
cable, if necessary.
(30) Install the transfer case skid plate, if
equipped.
(31) Lower vehicle.
(32) Fill transmission with MopartATF +4, Auto-
matic Transmission fluid.
Fig. 64 Gearshift Cable At Transmission
1 - GEARSHIFT CABLE
2 - TRANSMISSION MANUAL LEVER
3 - CABLE SUPPORT BRACKET
Fig. 65 Transmission Cooler Lines
1 - TRANSMISSION
2 - RADIATOR
3 - COOLER LINES
DRAUTOMATIC TRANSMISSION - 48RE 21 - 175
AUTOMATIC TRANSMISSION - 48RE (Continued)

o-ring is properly installed and is free of any debris.
The hub must be smooth to avoid damaging pump
seal at installation.
(2) If a replacement transmission is being
installed, transfer any components necessary, such as
the manual shift lever and shift cable bracket, from
the original transmission onto the replacement trans-
mission.
(3) Lubricate oil pump seal lip with transmission
fluid.
(4) Align converter and oil pump.(5) Carefully insert converter in oil pump. Then
rotate converter back and forth until fully seated in
pump gears.
(6) Check converter seating with steel scale and
straightedge (Fig. 53). Surface of converter lugs
should be at least 13mm (1/2 in.) to rear of straight-
edge when converter is fully seated.
(7) Temporarily secure converter with C-clamp.
(8) Position transmission on jack and secure it
with chains.
(9) Check condition of converter driveplate.
Replace the plate if cracked, distorted or damaged.
Also be sure transmission dowel pins are seated
in engine block and protrude far enough to
hold transmission in alignment.
(10) Apply a light coating of MopartHigh Temp
Grease to the torque converter hub pocket in the rear
pocket of the engine's crankshaft.
(11) Raise transmission (Fig. 54) and align the
torque converter with the drive plate and transmis-
sion converter housing with the engine block.
(12) Move transmission forward. Then raise, lower
or tilt transmission to align the converter housing
with engine block dowels.
(13) Carefully work transmission forward and over
engine block dowels until converter hub is seated in
crankshaft. Verify that no wires, or the transmission
vent hose, have become trapped between the engine
block and the transmission.
(14) Install two bolts to attach the transmission to
the engine.
(15) Install remaining torque converter housing to
engine bolts. Tighten to 68 N´m (50 ft.lbs.).
Fig. 51 Install Primary Oil and Cooler Filters
1 - PRIMARY OIL FILTER
2 - COOLER RETURN FILTER
3 - COOLER RETURN FILTER BYPASS VALVE
4 - VALVE BODY
Fig. 52 Install Input, Output, and Line Pressure
Sensors
1 - OUTPUT SPEED SENSOR
2 - LINE PRESSURE SENSOR
3 - INPUT SPEED SENSOR
Fig. 53 Checking Torque Converter Seating - Typical
1 - SCALE
2 - STRAIGHTEDGE
21 - 334 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
AUTOMATIC TRANSMISSION - 45RFE/545RFE (Continued)

Immediately after a cold start, between predeter-
mined temperature thresholds limits, the three port
solenoid is briefly energized. This initializes the
pump by drawing air into the pump cavity and also
closes the vent seal. During non test conditions the
vent seal is held open by the pump diaphragm
assembly which pushes it open at the full travel posi-
tion. The vent seal will remain closed while the
pump is cycling due to the reed switch triggering of
the three port solenoid that prevents the diaphragm
assembly from reaching full travel. After the brief
initialization period, the solenoid is de-energized
allowing atmospheric pressure to enter the pump
cavity, thus permitting the spring to drive the dia-
phragm which forces air out of the pump cavity and
into the vent system. When the solenoid is energized
and de energized, the cycle is repeated creating flow
in typical diaphragm pump fashion. The pump is con-
trolled in 2 modes:
Pump Mode: The pump is cycled at a fixed rate to
achieve a rapid pressure build in order to shorten the
overall test length.
Test Mode: The solenoid is energized with a fixed
duration pulse. Subsequent fixed pulses occur when
the diaphragm reaches the Switch closure point.
The spring in the pump is set so that the system
will achieve an equalized pressure of about 7.5º H20.
The cycle rate of pump strokes is quite rapid as the
system begins to pump up to this pressure. As the
pressure increases, the cycle rate starts to drop off. If
there is no leak in the system, the pump would even-
tually stop pumping at the equalized pressure. If
there is a leak, it will continue to pump at a rate rep-
resentative of the flow characteristic of the size of the
leak. From this information we can determine if the
leak is larger than the required detection limit (cur-
rently set at .040º orifice by CARB). If a leak is
revealed during the leak test portion of the test, the
test is terminated at the end of the test mode and no
further system checks will be performed.
After passing the leak detection phase of the test,
system pressure is maintained by turning on the
LDP's solenoid until the purge system is activated.
Purge activation in effect creates a leak. The cycle
rate is again interrogated and when it increases due
to the flow through the purge system, the leak check
portion of the diagnostic is complete.
The canister vent valve will unseal the system
after completion of the test sequence as the pump
diaphragm assembly moves to the full travel position.
Evaporative system functionality will be verified by
using the stricter evap purge flow monitor. At an
appropriate warm idle the LDP will be energized to
seal the canister vent. The purge flow will be clocked
up from some small value in an attempt to see a
shift in the 02 control system. If fuel vapor, indicatedby a shift in the 02 control, is present the test is
passed. If not, it is assumed that the purge system is
not functioning in some respect. The LDP is again
turned off and the test is ended.
MISFIRE MONITOR
Excessive engine misfire results in increased cata-
lyst temperature and causes an increase in HC emis-
sions. Severe misfires could cause catalyst damage.
To prevent catalytic convertor damage, the PCM
monitors engine misfire.
The Powertrain Control Module (PCM) monitors
for misfire during most engine operating conditions
(positive torque) by looking at changes in the crank-
shaft speed. If a misfire occurs the speed of the
crankshaft will vary more than normal.
FUEL SYSTEM MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide. The catalyst works best
when the Air Fuel (A/F) ratio is at or near the opti-
mum of 14.7 to 1.
The PCM is programmed to maintain the optimum
air/fuel ratio of 14.7 to 1. This is done by making
short term corrections in the fuel injector pulse width
based on the O2S sensor output. The programmed
memory acts as a self calibration tool that the engine
controller uses to compensate for variations in engine
specifications, sensor tolerances and engine fatigue
over the life span of the engine. By monitoring the
actual fuel-air ratio with the O2S sensor (short term)
and multiplying that with the program long-term
(adaptive) memory and comparing that to the limit,
it can be determined whether it will pass an emis-
sions test. If a malfunction occurs such that the PCM
cannot maintain the optimum A/F ratio, then the
MIL will be illuminated.
CATALYST MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide.
Normal vehicle miles or engine misfire can cause a
catalyst to decay. This can increase vehicle emissions
and deteriorate engine performance, driveability and
fuel economy.
The catalyst monitor uses dual oxygen sensors
(O2S's) to monitor the efficiency of the converter. The
dual O2S's sensor strategy is based on the fact that
as a catalyst deteriorates, its oxygen storage capacity
and its efficiency are both reduced. By monitoring
the oxygen storage capacity of a catalyst, its effi-
ciency can be indirectly calculated. The upstream
DREMISSIONS CONTROL 25 - 3
EMISSIONS CONTROL (Continued)