2002 DODGE RAM oil

nector at all times. If OK, go to Step 4. If not OK,
repair the open circuit to the horn(s) as required.
(4) The coil battery terminal (86) is connected to
the electromagnet in the relay. It is connected to bat-
tery voltage and should be hot at all times. Check for
battery voltage at the cavity for relay terminal 86. If
OK, go to Step 5. If not OK, repair the open circuit to
the fuse in the PDC as required.
(5) The coil ground terminal (85) is connected to
the electromagnet in the relay. It is grounded
through the horn switch when the horn switch is
depressed. On vehicles equipped with the Vehicle
Theft Security System (VTSS), the horn relay coil
ground terminal can also be grounded by the Central
Timer Module (CTM) in response to certain inputs
related to the VTSS or Remote Keyless Entry (RKE)
system. Check for continuity to ground at the cavity
for relay terminal 85. There should be continuity
with the horn switch depressed, and no continuity
with the horn switch released. If not OK, (Refer to 8
- ELECTRICAL/HORN/HORN SWITCH - DIAGNO-
SIS AND TESTING).
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cover from the Power Distribution
Center (PDC) (Fig. 3) .
(3) See the fuse and relay layout label affixed to
the underside of the PDC cover for horn relay iden-
tification and location.
(4) Remove the horn relay from the PDC.
INSTALLATION
(1) See the fuse and relay layout label affixed to
the underside of the PDC cover for the proper horn
relay location.
(2) Position the horn relay in the proper receptacle
in the PDC.
(3) Align the horn relay terminals with the termi-
nal cavities in the PDC receptacle.
(4) Push down firmly on the horn relay until the
terminals are fully seated in the terminal cavities in
the PDC receptacle.
(5) Install the cover onto the PDC.
(6) Reconnect the battery negative cable.
HORN SWITCH
DESCRIPTION
A center-blow, normally open, resistive membrane-
type horn switch is secured with heat stakes to the
back side of the driver side airbag module trim cover
in the center of the steering wheel (Fig. 4) . The
switch consists of two plastic membranes, one that is
flat and one that is slightly convex. These two mem-
branes are secured to each other around the perime-
ter. Inside the switch, the centers of the facing
surfaces of these membranes each has a grid made
with an electrically conductive material applied to it.
One of the grids is connected to a circuit that pro-
vides it with continuity to ground at all times. The
grid of the other membrane is connected to the horn
relay control circuit.
The steering wheel and steering column must be
properly grounded in order for the horn switch to
function properly. The horn switch is only serviced as
a part of the driver side airbag module trim cover. If
Fig. 2 Horn Relay
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
Fig. 3 Power Distribution Center
1 - COVER
2 - POWER DISTRIBUTION CENTER
8H - 4 HORNBR/BE
HORN RELAY (Continued)

the horn switch is damaged or faulty, or if the driver
side airbag is deployed, the driver side airbag module
trim cover and horn switch must be replaced as a
unit.
OPERATION
When the center area of the driver side airbag trim
cover is depressed, the electrically conductive grids
on the facing surfaces of the horn switch membranes
contact each other, closing the switch circuit. The
completed horn switch circuit provides a ground for
the control coil side of the horn relay, which activates
the relay. When the horn switch is released, the
resistive tension of the convex membrane separates
the two electrically conductive grids and opens the
switch circuit.
DIAGNOSIS AND TESTING - HORN SWITCH
For complete circuit diagrams, refer to the appro-
priate wiring information. The wiring information
includes wiring diagrams, proper wire and connector
repair procedures, details of wire harness routing
and retention, connector pin-out information and
location views for the various wire harness connec-
tors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTSBEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable. Remove the steering column opening cover
from the instrument panel.
(2) Check for continuity between the metal steer-
ing column jacket and a good ground. There should
be continuity. If OK, go to Step 3. If not OK,(Refer to
19 - STEERING/COLUMN - INSTALLATION) for
proper installation of the steering column.
(3) Remove the driver side airbag module from the
steering wheel. Disconnect the horn switch wire har-
ness connectors from the driver side airbag module.
(4) Remove the horn relay from the Power Distri-
bution Center (PDC). Check for continuity between
the steering column half of the horn switch feed wire
harness connector and a good ground. There should
be no continuity. If OK, go to Step 5. If not OK,
repair the shorted horn relay control circuit to the
horn relay in the PDC as required.
(5) Check for continuity between the steering col-
umn half of the horn switch feed wire harness con-
nector and the horn relay control circuit cavity for
the horn relay in the PDC. There should be continu-
ity. If OK, go to Step 6. If not OK, repair the open
horn relay control circuit to the horn relay in the
PDC as required.
(6) Check for continuity between the horn switch
feed wire and the horn switch ground wire on the
driver side airbag module. There should be no conti-
nuity. If OK, go to Step 7. If not OK, replace the
faulty horn switch.
(7) Depress the center of the driver side airbag
module trim cover and check for continuity between
the horn switch feed wire and the horn switch
ground wire on the driver side airbag module. There
should now be continuity. If not OK, replace the
faulty horn switch.REMOVAL
If the horn switch is damaged or faulty, or if the
driver side airbag is deployed, the driver side airbag
module trim cover and horn switch must be replaced
as a unit. (Refer to 8 - ELECTRICAL/RESTRAINTS/
DRIVER AIRBAG - REMOVAL).
Fig. 4 Driver Side Airbag Module Trim Cover and
Horn Switch
1 - RETAINER SLOTS
2 - LOCKING BLOCKS
3 - RETAINER SLOTS
4 - HORN SWITCH
BR/BEHORN 8H - 5
HORN SWITCH (Continued)

IGNITION CONTROL
TABLE OF CONTENTS
page page
IGNITION CONTROL
DESCRIPTION - 8.0L V-10.................2
OPERATION
OPERATION - 8.0L V-10.................2
OPERATION - V-8......................2
SPECIFICATIONS
SPECIFICATIONS - TORQUE - IGNITION....2
SPARK PLUG CABLE ORDERÐ8.0L V-10
ENGINE..............................3
ENGINE FIRING ORDERÐ5.9L V-8
ENGINES............................3
SPARK PLUG CABLE RESISTANCE........3
SPARK PLUGS........................3
IGNITION COIL RESISTANCEÐ5.9L
ENGINES............................3
IGNITION COIL RESISTANCEÐ8.0L V-10
ENGINE..............................4
IGNITION TIMING......................4
AUTOMATIC SHUT DOWN RELAY
DESCRIPTION - PCM OUTPUT.............4
OPERATION
OPERATION - PCM OUTPUT.............4
OPERATION - ASD SENSE - PCM INPUT....4
DIAGNOSIS AND TESTING - ASD AND FUEL
PUMP RELAYS........................4
REMOVAL.............................5
INSTALLATION..........................5
CAMSHAFT POSITION SENSOR
DESCRIPTION
DESCRIPTION - DIESEL.................6
DESCRIPTION - 5.9L....................6
DESCRIPTION - 8.0L....................6
OPERATION
OPERATION - DIESEL...................6
OPERATION - 5.9L.....................7
OPERATION - 8.0L.....................7
REMOVAL
REMOVAL - DIESEL....................7
REMOVAL - 5.9L.......................7
REMOVAL - 8.0L.......................8
INSTALLATION
INSTALLATION - DIESEL.................9INSTALLATION - 5.9L..................10
INSTALLATION - 8.0L..................10
DISTRIBUTOR
DESCRIPTION.........................11
OPERATION...........................12
REMOVAL.............................12
INSTALLATION.........................13
DISTRIBUTOR CAP
DIAGNOSIS AND TESTING - DISTRIBUTOR
CAP ................................14
DISTRIBUTOR ROTOR
DIAGNOSIS AND TESTING - DISTRIBUTOR
ROTOR .............................14
IGNITION COIL
DESCRIPTION
DESCRIPTION - 5.9L...................15
DESCRIPTION - 8.0L...................15
OPERATION
OPERATION - 5.9L....................15
OPERATION - 8.0L....................15
REMOVAL
REMOVAL - 5.9L......................15
REMOVAL - 8.0L......................16
INSTALLATION
INSTALLATION - 5.9L..................16
INSTALLATION - 8.0L..................16
SPARK PLUG
DESCRIPTION.........................16
OPERATION...........................16
DIAGNOSIS AND TESTING - SPARK PLUG
CONDITIONS.........................17
REMOVAL.............................19
CLEANING............................20
INSTALLATION.........................20
SPARK PLUG CABLE
DESCRIPTION.........................20
OPERATION...........................20
DIAGNOSIS AND TESTING - SPARK PLUG
CABLES............................20
REMOVAL.............................21
INSTALLATION.........................21
BR/BEIGNITION CONTROL 8I - 1

IGNITION CONTROL
DESCRIPTION - 8.0L V-10
The ignition system used on the 8.0L V±10 engine
does not use a conventional mechanical distributor.
The system will be referred to as a distributor-less
ignition system.
OPERATION
OPERATION - 8.0L V-10
The ignition coils are individually fired, but each
coil is a dual output. Refer to Ignition Coil for addi-
tional information.
The ignition system is controlled by the Powertrain
Control Module (PCM) on all engines.
The ignition system consists of:
²Spark Plugs
²Ignition Coil packs containing individual coils
²Secondary Ignition Cables²Powertrain Control Module (PCM)
²Also to be considered part of the ignition system
are certain inputs from the Crankshaft Position,
Camshaft Position, Throttle Position and MAP Sen-
sors
OPERATION - V-8
The ignition system is controlled by the Powertrain
Control Module (PCM) on all engines.
The ignition system consists of:
²Spark Plugs
²Ignition Coil
²Secondary Ignition Cables
²Distributor (contains rotor and camshaft position
sensor)
²Powertrain Control Module (PCM)
²Also to be considered part of the ignition system
are certain inputs from the Crankshaft Position,
Camshaft Position, Throttle Position and MAP Sen-
sors
SPECIFICATIONS
SPECIFICATIONS - TORQUE - IGNITION
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Camshaft Position
SensorÐ8.0L Engine6
-50
Crankshaft Position
SensorÐAll Engines8-70
Distributor Hold Down Bolt 23 17 -
Ignition Coil MountingÐ
5.9L EnginesÐif tapped
bolts are used5-50
Ignition Coil MountingÐ
5.9L EnginesÐif nuts/bolts
are used11 - 100
Ignition Coil MountingÐ
8.0L Engine10 - 90
Spark Plugs (all engines) 41 - 30
8I - 2 IGNITION CONTROLBR/BE

SPARK PLUG CABLE ORDERÐ8.0L V-10
ENGINEENGINE FIRING ORDERÐ5.9L V-8 ENGINES
SPARK PLUG CABLE RESISTANCE
MINIMUM MAXIMUM
250 Ohms Per Inch 1000 Ohms Per Inch
3000 Ohms Per Foot 12,000 Ohms Per Foot
SPARK PLUGS
ENGINE PLUG TYPE ELECTRODE GAP
5.9L V-8 RC12LC4 1.01 mm (.040 in.)
8.0L V-10 QC9MC4 1.14 mm (.045 in.)
IGNITION COIL RESISTANCEÐ5.9L ENGINES
COIL MANUFACTURERPRIMARY RESISTANCE
21-27ÉC (70-80ÉF)SECONDARY RESISTANCE 21-27ÉC
(70-80ÉF)
Diamond 0.97 - 1.18 Ohms 11,300 - 15,300 Ohms
Toyodenso 0.95 - 1.20 Ohms 11,300 - 13,300 Ohms
Spark Plug Cable OrderÐ8.0L V-10 Engine
BR/BEIGNITION CONTROL 8I - 3
IGNITION CONTROL (Continued)

IGNITION COIL RESISTANCEÐ8.0L V-10
ENGINE
Primary Resistance: 0.53-0.65 Ohms. Test across the
primary connector. Refer to text for test procedures.
Secondary Resistance: 10.9-14.7K Ohms. Test
across the individual coil towers. Refer to text for test
procedures.
IGNITION TIMING
Ignition timing is not adjustable on any engine.
AUTOMATIC SHUT DOWN
RELAY
DESCRIPTION - PCM OUTPUT
The 5±pin, 12±volt, Automatic Shutdown (ASD)
relay is located in the Power Distribution Center
(PDC). Refer to label on PDC cover for relay location.
OPERATION
OPERATION - PCM OUTPUT
The ASD relay supplies battery voltage (12+ volts)
to the fuel injectors and ignition coil(s). With certain
emissions packages it also supplies 12±volts to the
oxygen sensor heating elements.
The ground circuit for the coil within the ASD
relay is controlled by the Powertrain Control Module
(PCM). The PCM operates the ASD relay by switch-
ing its ground circuit on and off.
The ASD relay will be shut±down, meaning the
12±volt power supply to the ASD relay will be de-ac-
tivated by the PCM if:
²the ignition key is left in the ON position. This
is if the engine has not been running for approxi-
mately 1.8 seconds.
²there is a crankshaft position sensor signal to
the PCM that is lower than pre-determined values.
OPERATION - ASD SENSE - PCM INPUT
A 12 volt signal at this input indicates to the PCM
that the ASD has been activated. The relay is used to
connect the oxygen sensor heater element, ignition
coil and fuel injectors to 12 volt + power supply.
This input is used only to sense that the ASD relay
is energized. If the Powertrain Control Module
(PCM) does not see 12 volts at this input when the
ASD should be activated, it will set a Diagnostic
Trouble Code (DTC).
DIAGNOSIS AND TESTING - ASD AND FUEL
PUMP RELAYS
The following description of operation and
tests apply only to the Automatic Shutdown
(ASD) and fuel pump relays. The terminals on the
bottom of each relay are numbered. Two different
types of relays may be used, (Fig. 1) or (Fig. 2).
Fig. 1 ASD and Fuel Pump Relay TerminalsÐType 1
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
Fig. 2 ASD and Fuel Pump Relay TerminalsÐType 2
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
8I - 4 IGNITION CONTROLBR/BE
IGNITION CONTROL (Continued)

²Terminal number 30 is connected to battery volt-
age. For both the ASD and fuel pump relays, termi-
nal 30 is connected to battery voltage at all times.
²The PCM grounds the coil side of the relay
through terminal number 85.
²Terminal number 86 supplies voltage to the coil
side of the relay.
²When the PCM de-energizes the ASD and fuel
pump relays, terminal number 87A connects to termi-
nal 30. This is the Off position. In the off position,
voltage is not supplied to the rest of the circuit. Ter-
minal 87A is the center terminal on the relay.
²When the PCM energizes the ASD and fuel
pump relays, terminal 87 connects to terminal 30.
This is the On position. Terminal 87 supplies voltage
to the rest of the circuit.
The following procedure applies to the ASD and
fuel pump relays.
(1) Remove relay from connector before testing.
(2) With the relay removed from the vehicle, use
an ohmmeter to check the resistance between termi-
nals 85 and 86. The resistance should be 75 ohms +/-
5 ohms.
(3) Connect the ohmmeter between terminals 30
and 87A. The ohmmeter should show continuity
between terminals 30 and 87A.
(4) Connect the ohmmeter between terminals 87
and 30. The ohmmeter should not show continuity at
this time.
(5) Connect one end of a jumper wire (16 gauge or
smaller) to relay terminal 85. Connect the other end
of the jumper wire to the ground side of a 12 volt
power source.
(6) Connect one end of another jumper wire (16
gauge or smaller) to the power side of the 12 volt
power source.Do not attach the other end of the
jumper wire to the relay at this time.
WARNING: DO NOT ALLOW OHMMETER TO CON-
TACT TERMINALS 85 OR 86 DURING THIS TEST.
DAMAGE TO OHMMETER MAY RESULT.
(7) Attach the other end of the jumper wire to
relay terminal 86. This activates the relay. The ohm-
meter should now show continuity between relay ter-
minals 87 and 30. The ohmmeter should not show
continuity between relay terminals 87A and 30.
(8) Disconnect jumper wires.(9) Replace the relay if it did not pass the continu-
ity and resistance tests. If the relay passed the tests,
it operates properly. Check the remainder of the ASD
and fuel pump relay circuits. Refer to 8, Wiring Dia-
grams.
REMOVAL
The ASD relay is located in the Power Distribution
Center (PDC) (Fig. 3). Refer to label on PDC cover
for relay location.
(1) Remove PDC cover.
(2) Remove relay from PDC.
(3) Check condition of relay terminals and PDC
connector terminals for damage or corrosion. Repair
if necessary before installing relay.
(4) Check for pin height (pin height should be the
same for all terminals within the PDC connector).
Repair if necessary before installing relay.
INSTALLATION
The ASD relay is located in the Power Distribution
Center (PDC) (Fig. 3). Refer to label on PDC cover
for relay location.
(1) Install relay to PDC.
(2) Install cover to PDC.
Fig. 3 Power Distribution Center (PDC)
1 - POWER DISTRIBUTION CENTER (PDC)
BR/BEIGNITION CONTROL 8I - 5
AUTOMATIC SHUT DOWN RELAY (Continued)

A thin plastic rib is molded into the face of the sen-
sor (Fig. 13) to position the depth of sensor to the
upper cam gear (sprocket). This rib can be found on
both the new replacement sensors and sensors that
were originally installed to the engine. The first time
the engine has been operated, part of this rib may be
sheared (ground) off. Depending on parts tolerances,
some of the rib material may still be observed after
removal.
Refer to either of the following procedures; Replac-
ing Old Sensor With Original, or Replacing With
New Sensor:REPLACING OLD SENSOR WITH ORIGINAL
If the original camshaft position sensor is to be
removed and installed, such as when servicing the
timing chain, timing gears or timing chain cover, use
this procedure.
(1) Disconnect the sensor harness connector from
the sensor.
(2) Remove the sensor mounting bolt (Fig. 12).
(3) Carefully pry the sensor from the timing chain
case/cover in a rocking action with two small screw-
drivers.
(4) Remove the sensor from vehicle.
(5) Check condition of sensor o-ring (Fig. 14).
REPLACING WITH NEW SENSOR
If a new replacement camshaft position sensor is to
be installed, use this procedure.
(1) Disconnect the sensor wiring harness connector
from sensor.
(2) Remove the sensor mounting bolt (Fig. 12).
(3) Carefully pry the sensor from the timing chain
case/cover in a rocking action with two small screw-
drivers.
(4) Remove the sensor from vehicle.
INSTALLATION
INSTALLATION - DIESEL
The camshaft position sensor (CMP) is located
below the fuel injection pump (Fig. 9). It is attached
to the back of the timing gear cover housing.
(1) Install new o-ring to CMP. Apply clean engine
oil to o-ring.
(2) Clean area around CMP mounting hole.
(3) To prevent tearing o-ring, install CMP into
gear housing using a twisting action.
Fig. 12 CMP Location - 8.0L
1 - CAMSHAFT POSITION SENSOR
2 - MOUNTING BOLT
3 - TIMING CHAIN CASE/COVER
Fig. 13 Sensor Depth Positioning RibÐ8.0L V-10
Engine
1 - CAMSHAFT POSITION SENSOR
2 - PAPER SPACER
3 - RIB MATERIAL (FOR SENSOR DEPTH POSITIONING)
Fig. 14 Camshaft Sensor O-RingÐ8.0L
1 - SLOTTED MOUNTING HOLE
2 - SCRIBE LINE
3 - CAMSHAFT POSITION SENSOR O-RING
BR/BEIGNITION CONTROL 8I - 9
CAMSHAFT POSITION SENSOR (Continued)