2001 DODGE RAM oil temperature

²Power ground
²Sensor return
²Signal ground
²Speed control resume switch
²Speed control set switch
²Speed control on/off switch
²Transmission governor pressure sensor
²Transmission temperature sensor
²Vehicle speed inputs from ABS or RWAL system
NOTE: PCM Outputs:
After inputs are received by the PCM, certain sen-
sors, switches and components are controlled or reg-
ulated by the PCM. These are consideredPCM
Outputs.These outputs are for:
²A/C clutch relay and A/C clutch
²Auto shutdown (ASD) relay
²CCD bus (+/-) circuits for: speedometer, voltme-
ter, fuel gauge, oil pressure gauge/lamp, engine temp.
gauge and speed control warn. lamp
²Data link connection for DRB scan tool
²Five volt sensor supply
²Generator field driver (-)
²Generator field driver (+)
²Generator lamp (if equipped)
²Malfunction indicator lamp (Check engine lamp)
²Overdrive warning lamp (if equipped)
²Speed control vacuum solenoid
²Speed control vent solenoid
²Tachometer (if equipped)
²Transmission convertor clutch circuit
²Transmission 3±4 shift solenoid
²Transmission relay
²Transmission temperature lamp (if equipped)
²Transmission variable force solenoid (governor
sol.)
OPERATION - 5 VOLT SUPPLIES
Primary 5±volt supply:
²supplies the required 5 volt power source to the
Crankshaft Position (CKP) sensor.
²supplies the required 5 volt power source to the
Camshaft Position (CMP) sensor.
²supplies a reference voltage for the Manifold
Absolute Pressure (MAP) sensor.
²supplies a reference voltage for the Throttle
Position Sensor (TPS) sensor.
Secondary 5±volt supply:
²supplies the required 5 volt power source to the
oil pressure sensor.
²supplies the required 5 volt power source for the
Vehicle Speed Sensor (VSS) (if equipped).
²supplies the 5 volt power source to the transmis-
sion pressure sensor (if equipped with an RE auto-
matic transmission).
OPERATION - IGNITION CIRCUIT SENSE
The ignition circuit sense input tells the PCM the
ignition switch has energized the ignition circuit.
Battery voltage is also supplied to the PCM
through the ignition switch when the ignition is in
the RUN or START position. This is referred to as
the9ignition sense9circuit and is used to9wake up9
the PCM. Voltage on the ignition input can be as low
as 6 volts and the PCM will still function. Voltage is
supplied to this circuit to power the PCM's 8-volt reg-
ulator and to allow the PCM to perform fuel, ignition
and emissions control functions.
REMOVAL
USE THE DRB SCAN TOOL TO REPROGRAM
THE NEW POWERTRAIN CONTROL MODULE
(PCM) WITH THE VEHICLES ORIGINAL IDEN-
TIFICATION NUMBER (VIN) AND THE VEHI-
CLES ORIGINAL MILEAGE. IF THIS STEP IS
NOT DONE, A DIAGNOSTIC TROUBLE CODE
(DTC) MAY BE SET.
The PCM is located in the engine compartment
(Fig. 18).
To avoid possible voltage spike damage to the
PCM, ignition key must be off, and negative battery
cable must be disconnected before unplugging PCM
connectors.
(1) Disconnect negative battery cable(s) at bat-
tery(s).
(2) Remove cover over electrical connectors. Cover
snaps onto PCM.
(3) Carefully unplug the three 32±way connectors
from PCM.
Fig. 18 PCM Location and Mounting
1 - PCM MOUNTING BOLTS (3)
2 - POWERTRAIN CONTROL MODULE (PCM)
3 - (3) 32±WAY CONNECTORS
BR/BEELECTRONIC CONTROL MODULES 8E - 19
POWERTRAIN CONTROL MODULE (Continued)

(2) Look through the battery cap holes to deter-
mine the level of the electrolyte in the battery (Fig.
6). The electrolyte should be approximately 1 centi-
meter above the battery plates or until the hook
inside the battery cap holes is covered.
(3) Add only distilled water until the electrolyte
level is approx. one centimeter above the plates.
STANDARD PROCEDURE - BATTERY
CHARGING
Battery charging is the means by which the bat-
tery can be restored to its full voltage potential. A
battery is fully-charged when:
²All of the battery cells are gassing freely during
battery charging.
²A green color is visible in the sight glass of the
battery built-in test indicator.
²Three hydrometer tests, taken at one-hour inter-
vals, indicate no increase in the temperature-cor-
rected specific gravity of the battery electrolyte.
²Open-circuit voltage of the battery is 12.65 volts
or above.
WARNING: NEVER EXCEED TWENTY AMPERES
WHEN CHARGING A COLD (-1É C [30É F] OR
LOWER) BATTERY. THE BATTERY MAY ARC INTER-
NALLY AND EXPLODE. PERSONAL INJURY AND/OR
VEHICLE DAMAGE MAY RESULT.WARNING: IF THE BATTERY SHOWS SIGNS OF
FREEZING, LEAKING OR LOOSE POSTS, DO NOT
TEST, ASSIST-BOOST, OR CHARGE. THE BATTERY
MAY ARC INTERNALLY AND EXPLODE. PERSONAL
INJURY AND/OR VEHICLE DAMAGE MAY RESULT.
WARNING: EXPLOSIVE HYDROGEN GAS FORMS IN
AND AROUND THE BATTERY. DO NOT SMOKE,
USE FLAME, OR CREATE SPARKS NEAR THE BAT-
TERY. PERSONAL INJURY AND/OR VEHICLE DAM-
AGE MAY RESULT.
WARNING: THE BATTERY CONTAINS SULFURIC
ACID, WHICH IS POISONOUS AND CAUSTIC. AVOID
CONTACT WITH THE SKIN, EYES, OR CLOTHING.
IN THE EVENT OF CONTACT, FLUSH WITH WATER
AND CALL A PHYSICIAN IMMEDIATELY. KEEP OUT
OF THE REACH OF CHILDREN.
WARNING: IF THE BATTERY IS EQUIPPED WITH
REMOVABLE CELL CAPS, BE CERTAIN THAT EACH
OF THE CELL CAPS IS IN PLACE AND TIGHT
BEFORE THE BATTERY IS RETURNED TO SER-
VICE. PERSONAL INJURY AND/OR VEHICLE DAM-
AGE MAY RESULT FROM LOOSE OR MISSING
CELL CAPS.
CAUTION: Always disconnect and isolate the bat-
tery negative cable before charging a battery. Do
not exceed sixteen volts while charging a battery.
Damage to the vehicle electrical system compo-
nents may result.
CAUTION: Battery electrolyte will bubble inside the
battery case during normal battery charging. Elec-
trolyte boiling or being discharged from the battery
vents indicates a battery overcharging condition.
Immediately reduce the charging rate or turn off the
charger to evaluate the battery condition. Damage
to the battery may result from overcharging.
CAUTION: The battery should not be hot to the
touch. If the battery feels hot to the touch, turn off
the charger and let the battery cool before continu-
ing the charging operation. Damage to the battery
may result.
Fig. 6 Hook Inside Battery Cap Holes - Export
Battery
1 - BATTERY SURFACE COVER
2 - HOOK
BR/BEBATTERY SYSTEM 8F - 9
BATTERY (Continued)

CHARGING
TABLE OF CONTENTS
page page
CHARGING
DESCRIPTION...........................27
OPERATION.............................27
DIAGNOSIS AND TESTING.................27
CHARGING SYSTEM....................27
SPECIFICATIONS........................28
BATTERY TEMPERATURE SENSOR
DESCRIPTION...........................29
OPERATION.............................29
REMOVAL..............................29INSTALLATION...........................29
GENERATOR
DESCRIPTION...........................29
OPERATION.............................29
REMOVAL..............................30
INSTALLATION...........................30
VOLTAGE REGULATOR
DESCRIPTION...........................31
OPERATION.............................31
CHARGING
DESCRIPTION
The charging system consists of:
²Generator
²Electronic Voltage Regulator (EVR) circuitry
within the Powertrain Control Module (PCM)
²Ignition switch (refer to Ignition System for
information)
²Battery (refer to 8, Battery for information)
²Battery temperature sensor
²Check Gauges Lamp (if equipped)
²Voltmeter (refer to 8, Instrument Panel and
Gauges for information)
²Wiring harness and connections (refer to 8, Wir-
ing Diagrams for information)
OPERATION
The charging system is turned on and off with the
ignition switch. The system is on when the engine is
running and the ASD relay is energized. When the
ASD relay is on, voltage is supplied to the ASD relay
sense circuit at the PCM. This voltage is connected
through the PCM and supplied to one of the genera-
tor field terminals (Gen. Source +) at the back of the
generator.
The amount of direct current produced by the gen-
erator is controlled by the EVR (field control) cir-
cuitry contained within the PCM. This circuitry is
connected in series with the second rotor field termi-
nal and ground.
A battery temperature sensor, located in the bat-
tery tray housing, is used to sense battery tempera-
ture. This temperature data, along with data from
monitored line voltage, is used by the PCM to vary
the battery charging rate. This is done by cycling the
ground path to control the strength of the rotor mag-netic field. The PCM then compensates and regulates
generator current output accordingly.
All vehicles are equipped with On-Board Diagnos-
tics (OBD). All OBD-sensed systems, including EVR
(field control) circuitry, are monitored by the PCM.
Each monitored circuit is assigned a Diagnostic Trou-
ble Code (DTC). The PCM will store a DTC in elec-
tronic memory for certain failures it detects. Refer to
On-Board Diagnostics in 25, Emission Control Sys-
tem for more DTC information and a list of codes.
The Check Gauges Lamp (if equipped) monitors:
charging system voltage,engine coolant tempera-
ture and engine oil pressure. If an extreme condition
is indicated, the lamp will be illuminated. This is
done as reminder to check the three gauges. The sig-
nal to activate the lamp is sent via the CCD bus cir-
cuits. The lamp is located on the instrument panel.
Refer to 8, Instrument Panel and Gauges for addi-
tional information.
DIAGNOSIS AND TESTING - CHARGING
SYSTEM
The following procedures may be used to diagnose
the charging system if:
²the check gauges lamp (if equipped) is illumi-
nated with the engine running
²the voltmeter (if equipped) does not register
properly
²an undercharged or overcharged battery condi-
tion occurs.
Remember that an undercharged battery is often
caused by:
²accessories being left on with the engine not
running
²a faulty or improperly adjusted switch that
allows a lamp to stay on. Refer to Ignition-Off Draw
Test in 8, Battery for more information.
BR/BECHARGING 8F - 27

BATTERY TEMPERATURE
SENSOR
DESCRIPTION
The Battery Temperature Sensor (BTS) is attached
to the battery tray located under the battery.
OPERATION
The BTS is used to determine the battery temper-
ature and control battery charging rate. This temper-
ature data, along with data from monitored line
voltage, is used by the PCM to vary the battery
charging rate. System voltage will be higher at colder
temperatures and is gradually reduced at warmer
temperatures.
The PCM sends 5 volts to the sensor and is
grounded through the sensor return line. As temper-
ature increases, resistance in the sensor decreases
and the detection voltage at the PCM increases.
The BTS is also used for OBD II diagnostics. Cer-
tain faults and OBD II monitors are either enabled
or disabled, depending upon BTS input (for example,
disable purge and enable Leak Detection Pump
(LDP) and O2 sensor heater tests). Most OBD II
monitors are disabled below 20ÉF.
REMOVAL
The battery temperature sensor is located under
the vehicle battery (Fig. 1) and is attached (snapped
into) a mounting hole on battery tray. On models
equipped with a diesel engine (dual batteries), only
one sensor is used. The sensor is located under the
battery on drivers side of vehicle.
(1) Remove battery. Refer to 8, Battery for proce-
dures.
(2) Disconnect sensor pigtail harness from engine
wire harness.
(3) Pry sensor straight up from battery tray
mounting hole.
INSTALLATION
The battery temperature sensor is located under
the vehicle battery (Fig. 1) and is attached (snapped
into) a mounting hole on battery tray. On models
equipped with a diesel engine (dual batteries), only
one sensor is used. The sensor is located under the
battery on drivers side of vehicle.
(1) Feed pigtail harness through mounting hole in
top of battery tray and press sensor into top of tray
(snaps in).
(2) Connect pigtail harness.
(3) Install battery. Refer to 8A, Battery for proce-
dures.
GENERATOR
DESCRIPTION
The generator is belt-driven by the engine using a
serpentine type drive belt. It is serviced only as a
complete assembly. If the generator fails for any rea-
son, the entire assembly must be replaced.
OPERATION
As the energized rotor begins to rotate within the
generator, the spinning magnetic field induces a cur-
rent into the windings of the stator coil. Once the
generator begins producing sufficient current, it also
provides the current needed to energize the rotor.
The Y type stator winding connections deliver the
induced alternating current to 3 positive and 3 neg-
ative diodes for rectification. From the diodes, recti-
fied direct current is delivered to the vehicle
electrical system through the generator battery ter-
minal.
Fig. 1 Battery Temperature Sensor Location
1 - BATT. TEMP. SENSOR
2 - BATTERY HOLD DOWN STRAP
3 - PIGTAIL HARNESS
4 - U-NUT
5 - U-NUT
6 - ELEC. CONNEC.
BR/BECHARGING 8F - 29

SPECIFICATIONS
STARTING SYSTEM
Starter Motor and Solenoid
Manufacturer Nippon Denso Nippon Denso Nippon Denso
Part Number 56027702AB 56027703AB 4741012
Engine Application3.9L, 5.2L, 5.9L
(Gasoline)8.0L (Gasoline) 5.9L (Diesel)
Power Rating1.4 Kilowatt
1.9 Horsepower1.4 Kilowatt
1.9 Horsepower2.7 Kilowatt
3.6 Horsepower
Voltage 12 Volts 12 Volts 12 Volts
Pinion Teeth 10 11 13
Number of Fields 4 4 4
Number of Poles 4 4 4
Number of Brushes 4 4 4
Drive Type Reduction Gear Train Reduction Gear Train Conventional Gear Train
Free Running Test Voltage 11 Volts 11 Volts 11 Volts
Free Running Test Amperage
Draw73 Amperes 73 Amperes 200 Amperes
Free Running Test Minimum
Speed3601 rpm 3601 rpm 3000 rpm
Solenoid Closing Maximum
Voltage Required7.5 Volts 7.5 Volts 8.0 Volts
* Cranking Amperage Draw
Test125 - 250 Amperes 125 - 250 Amperes 450 - 700 Amperes
* Test at operating temperature. Cold engine, tight (new) engine, or heavy oil will increase starter amperage draw.
SPECIFICATIONS - TORQUE - STARTING SYSTEM
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Battery Cable Eyelet Nut at Solenoid (large nut ± gas
engines)25 19 221
Battery Cable Eyelet Nut at Solenoid (large nut ± diesel
engine)14 120
Starter Solenoid Nut (small nut ± diesel engine) 6 55
Starter Mounting Bolts ± Gas Engines 68 50
Starter Mounting Nut ± Gas Engines 68 50
Starter Mounting Bolts ± Diesel 43 32
8F - 38 STARTINGBR/BE
STARTING (Continued)

removed). Then continue to slowly rotate engine
clockwise until indicating mark (Fig. 18) is aligned to
0 degree (TDC) mark on timing chain cover.
(1) Clean top of cylinder block for a good seal
between distributor base and block.
(2) Lightly oil the rubber o-ring seal on the distrib-
utor housing.
(3) Install rotor to distributor shaft.
(4) Position distributor into engine to its original
position. Engage tongue of distributor shaft with slot
in distributor oil pump drive gear. Position rotor to
the number one spark plug cable position.
(5) Install distributor holddown clamp and clamp
bolt. Do not tighten bolt at this time.(6) Rotate the distributor housing until rotor is
aligned to CYL. NO. 1 alignment mark on the cam-
shaft position sensor (Fig. 19) .
(7) Tighten clamp holddown bolt (Fig. 20) to 22.5
N´m (200 in. lbs.) torque.
(8) Connect camshaft position sensor wiring har-
ness to main engine harness.
(9) Install distributor cap. Tighten mounting
screws.
(10) Refer to the following, Checking Distributor
Position.
Checking Distributor Position
To verify correct distributor rotational position, the
DRB scan tool must be used.
WARNING: WHEN PERFORMING THE FOLLOWING
TEST, THE ENGINE WILL BE RUNNING. BE CARE-
FUL NOT TO STAND IN LINE WITH THE FAN
BLADES OR FAN BELT. DO NOT WEAR LOOSE
CLOTHING.
(1) Connect DRB scan tool to data link connector.
The data link connector is located in passenger com-
partment, below and to left of steering column.
(2) Gain access to SET SYNC screen on DRB.
(3) Follow directions on DRB screen and start
engine. Bring to operating temperature (engine must
be in ªclosed loopº mode).
(4) With engine running atidle speed, the words
IN RANGE should appear on screen along with 0É.
This indicates correct distributor position.
(5) If a plus (+) or a minus (-) is displayed next to
degree number, and/or the degree displayed is not
zero, loosen but do not remove distributor holddown
clamp bolt. Rotate distributor until IN RANGE
appears on screen. Continue to rotate distributor
until achieving as close to 0É as possible. After
adjustment, tighten clamp bolt to 22.5 N´m (200 in.
lbs.) torque.
The degree scale on SET SYNC screen of DRB is
referring to fuel synchronization only.It is not
referring to ignition timing.Because of this, do
not attempt to adjust ignition timing using this
method. Rotating distributor will have no effect on
ignition timing. All ignition timing values are con-
trolled by powertrain control module (PCM).
After testing, install air cleaner assembly.
DISTRIBUTOR CAP
DIAGNOSIS AND TESTING - DISTRIBUTOR
CAP
Remove the distributor cap and wipe it clean with
a dry lint free cloth. Visually inspect the cap for
cracks, carbon paths, broken towers or damaged
Fig. 19 Rotor Alignment Mark
1 - CAMSHAFT POSITION SENSOR ALIGNMENT MARK
2 - ROTOR
3 - DISTRIBUTOR
Fig. 20 Distributor Holddown Clamp
1 - CLAMP BOLT
2 - HOLDDOWN CLAMP
3 - DISTRIBUTOR HOUSING
8I - 12 IGNITION CONTROLBR/BE
DISTRIBUTOR (Continued)

filled coils. The rear coil pack contains two indepen-
dent epoxy filled coils.
OPERATION - 3.9L/5.2L/5.9L
The Powertrain Control Module (PCM) opens and
closes the ignition coil ground circuit for ignition coil
operation.
Battery voltage is supplied to the ignition coil pos-
itive terminal from the ASD relay. If the PCM does
not see a signal from the crankshaft and camshaft
sensors (indicating the ignition key is ON but the
engine is not running), it will shut down the ASD cir-
cuit.
Base ignition timing is not adjustable on any
engine.By controlling the coil ground circuit, the
PCM is able to set the base timing and adjust the
ignition timing advance. This is done to meet chang-
ing engine operating conditions.
OPERATION - 8.0L
When one of the 5 independent coils discharges, it
fires two paired cylinders at the same time (one cyl-
inder on compression stroke and the other cylinder
on exhaust stroke).
Coil firing is paired together on cylinders:
²Number 5 and 10
²Number 9 and 8
²Number 1 and 6
²Number 7 and 4
²Number 3 and 2
The ignition system is controlled by the Powertrain
Control Module (PCM) on all engines.
Battery voltage is supplied to all of the ignition
coils positive terminals from the ASD relay. If the
PCM does not see a signal from the crankshaft and
camshaft sensors (indicating the ignition key is ONbut the engine is not running), it will shut down the
ASD circuit.
Base ignition timing is not adjustable on the
8.0L V-10 engine.By controlling the coil ground cir-
cuit, the PCM is able to set the base timing and
adjust the ignition timing advance. This is done to
meet changing engine operating conditions.
The PCM adjusts ignition timing based on inputs it
receives from:
²The engine coolant temperature sensor
²The crankshaft position sensor (engine speed)
²The manifold absolute pressure (MAP) sensor
²The throttle position sensor
²Transmission gear selection
REMOVAL - 3.9L/5.2L/5.9L
The ignition coil is an epoxy filled type. If the coil
is replaced, it must be replaced with the same type.
3.9L V-6 or 5.2/5.9L V-8 LDC-Gas Engines: The coil
is mounted to a bracket that is bolted to the front of
the right engine cylinder head (Fig. 25). This bracket
is mounted on top of the automatic belt tensioner
bracket using common bolts.
5.9L V-8 HDC-Gas Engine: The coil is mounted to
a bracket that is bolted to the air injection pump
(AIR pump) mounting bracket (Fig. 26).
(1) Disconnect the primary wiring from the igni-
tion coil.
(2) Disconnect the secondary spark plug cable from
the ignition coil.
Fig. 24 Ignition Coil PacksÐ8.0L V-10 Engine
Fig. 25 Ignition CoilÐ3.9L V-6 or 5.2/5.9L V-8
LDC-Gas Engines
1 - ACCESSORY DRIVE BELT TENSIONER
2 - COIL CONNECTOR
3 - IGNITION COIL
4 - COIL MOUNTING BOLTS
8I - 14 IGNITION CONTROLBR/BE
IGNITION COIL (Continued)

CHIPPED ELECTRODE INSULATOR
A chipped electrode insulator usually results from
bending the center electrode while adjusting the
spark plug electrode gap. Under certain conditions,
severe detonation can also separate the insulator
from the center electrode (Fig. 33). Spark plugs with
this condition must be replaced.
PREIGNITION DAMAGE
Preignition damage is usually caused by excessive
combustion chamber temperature. The center elec-
trode dissolves first and the ground electrode dis-
solves somewhat latter (Fig. 34). Insulators appear
relatively deposit free. Determine if the spark plug
has the correct heat range rating for the engine.
Determine if ignition timing is over advanced or if
other operating conditions are causing engine over-
heating. (The heat range rating refers to the operat-
ing temperature of a particular type spark plug.
Spark plugs are designed to operate within specific
temperature ranges. This depends upon the thick-
ness and length of the center electrodes porcelain
insulator.)
SPARK PLUG OVERHEATING
Overheating is indicated by a white or gray center
electrode insulator that also appears blistered (Fig.
35). The increase in electrode gap will be consider-
ably in excess of 0.001 inch per 2000 miles of opera-
tion. This suggests that a plug with a cooler heat
range rating should be used. Over advanced ignition
timing, detonation and cooling system malfunctions
can also cause spark plug overheating.
REMOVAL
On 3.9L/5.2L/5.9L engines, spark plug cable heat
shields are pressed into the cylinder head to sur-
round each cable boot and spark plug (Fig. 36).
(1) Always remove spark plug or ignition coil
cables by grasping at the cable boot (Fig. 38). Turn
the cable boot 1/2 turn and pull straight back in a
steady motion. Never pull directly on the cable.
Internal damage to cable will result.
(2) Prior to removing the spark plug, spray com-
pressed air around the spark plug hole and the area
around the spark plug. This will help prevent foreign
material from entering the combustion chamber.
(3) Remove the spark plug using a quality socket
with a rubber or foam insert.
(4) Inspect the spark plug condition. Refer to
Spark Plug Condition in the Diagnostics and Testing
section of this group.
Fig. 33 Chipped Electrode Insulator
1 - GROUND ELECTRODE
2 - CENTER ELECTRODE
3 - CHIPPED INSULATOR
Fig. 34 Preignition Damage
1 - GROUND ELECTRODE STARTING TO DISSOLVE
2 - CENTER ELECTRODE DISSOLVED
Fig. 35 Spark Plug Overheating
1 - BLISTERED WHITE OR GRAY COLORED INSULATOR
8I - 18 IGNITION CONTROLBR/BE
SPARK PLUG (Continued)