ignition DODGE RAM 2001 Service Workshop Manual

A vehicle that has not been operated for approxi-
mately twenty days, may discharge the battery to an
inadequate level. When a vehicle will not be used for
twenty days or more (stored), remove the IOD fuse
from the Power Distribution Center (PDC). This will
reduce battery discharging.
Excessive IOD can be caused by:
²Electrical items left on.
²Faulty or improperly adjusted switches.
²Faulty or shorted electronic modules and compo-
nents.
²An internally shorted generator.
²Intermittent shorts in the wiring.If the IOD is over thirty-five milliamperes, the
problem must be found and corrected before replac-
ing a battery. In most cases, the battery can be
charged and returned to service after the excessive
IOD condition has been corrected.
(1) Verify that all electrical accessories are off.
Turn off all lamps, remove the ignition key, and close
all doors. If the vehicle is equipped with an illumi-
nated entry system or an electronically tuned radio,
allow the electronic timer function of these systems
to automatically shut off (time out). This may take
up to three minutes. See the Electronic Module Igni-
tion-Off Draw Table for more information.
ELECTRONIC MODULE IGNITION-OFF DRAW (IOD) TABLE
ModuleTime Out?
(If Yes, Interval And Wake-Up Input)IODIOD After Time
Out
Radio No1to3
milliamperesN/A
Audio Power
AmplifierNoup to 1
milliampereN/A
Central Timer Module
(CTM)No4.75
milliamperes
(max.)N/A
Powertrain Control
Module (PCM)No 0.95 milliampere N/A
ElectroMechanical
Instrument Cluster
(EMIC)No 0.44 milliampere N/A
Combination Flasher No 0.08 milliampere N/A
(2) Determine that the underhood lamp is operat-
ing properly, then disconnect the lamp wire harness
connector or remove the lamp bulb.
(3) Disconnect the battery negative cable.
(4) Set an electronic digital multi-meter to its
highest amperage scale. Connect the multi-meter
between the disconnected battery negative cable ter-
minal clamp and the battery negative terminal post.
Make sure that the doors remain closed so that the
illuminated entry system is not activated. The multi-
meter amperage reading may remain high for up to
three minutes, or may not give any reading at all
while set in the highest amperage scale, depending
upon the electrical equipment in the vehicle. The
multi-meter leads must be securely clamped to the
battery negative cable terminal clamp and the bat-
tery negative terminal post. If continuity between the
battery negative terminal post and the negative cable
terminal clamp is lost during any part of the IOD
test, the electronic timer function will be activated
and all of the tests will have to be repeated.(5) After about three minutes, the high-amperage
IOD reading on the multi-meter should become very
low or nonexistent, depending upon the electrical
equipment in the vehicle. If the amperage reading
remains high, remove and replace each fuse or circuit
breaker in the Power Distribution Center (PDC) and
then in the Junction Block (JB), one at a time until
the amperage reading becomes very low, or nonexist-
ent. Refer to the appropriate wiring information in
this service manual for complete PDC and JB fuse,
circuit breaker, and circuit identification. This will
isolate each circuit and identify the circuit that is the
source of the high-amperage IOD. If the amperage
reading remains high after removing and replacing
each fuse and circuit breaker, disconnect the wire
harness from the generator. If the amperage reading
now becomes very low or nonexistent, refer to Charg-
ing System for the proper charging system diagnosis
and testing procedures. After the high-amperage IOD
has been corrected, switch the multi-meter to pro-
gressively lower amperage scales and, if necessary,
repeat the fuse and circuit breaker remove-and-re-
8F - 16 BATTERY SYSTEMBR/BE
BATTERY (Continued)

place process to identify and correct all sources of
excessive IOD. It is now safe to select the lowest mil-
liampere scale of the multi-meter to check the low-
amperage IOD.
CAUTION: Do not open any doors, or turn on any
electrical accessories with the lowest milliampere
scale selected, or the multi-meter may be damaged.
(6) Observe the multi-meter reading. The low-am-
perage IOD should not exceed thirty-five milliam-
peres (0.035 ampere). If the current draw exceeds
thirty-five milliamperes, isolate each circuit using the
fuse and circuit breaker remove-and-replace process
in Step 5. The multi-meter reading will drop to
within the acceptable limit when the source of the
excessive current draw is disconnected. Repair this
circuit as required; whether a wiring short, incorrect
switch adjustment, or a component failure is at fault.
REMOVAL
(1) Turn the ignition switch to the Off position. Be
certain that all electrical accessories are turned off.
(2) Loosen the battery negative cable terminal
clamp pinch-bolt hex nut.
(3) Disconnect the battery negative cable terminal
clamp from the battery negative terminal post. If
necessary, use a battery terminal puller to remove
the terminal clamp from the battery post (Fig. 16).
(4) Loosen the battery positive cable terminal
clamp pinch-bolt hex nut.
(5) Disconnect the battery positive cable terminal
clamp from the battery positive terminal post. If nec-
essary, use a battery terminal puller to remove the
terminal clamp from the battery post.
(6) Remove the battery hold downs from the bat-
tery. Refer toBattery Hold Downsin this group for
the location of the proper battery hold down removal
procedures.WARNING: WEAR A SUITABLE PAIR OF RUBBER
GLOVES (NOT THE HOUSEHOLD TYPE) WHEN
REMOVING A BATTERY BY HAND. SAFETY
GLASSES SHOULD ALSO BE WORN. IF THE BAT-
TERY IS CRACKED OR LEAKING, THE ELECTRO-
LYTE CAN BURN THE SKIN AND EYES.
(7) Remove the battery from the battery tray.
INSTALLATION
(1) Clean and inspect the battery. Refer toBat-
tery Systemin this group for the location of the
proper battery system cleaning and inspection proce-
dures.
(2) Position the battery onto the battery tray.
Ensure that the battery positive and negative termi-
nal posts are correctly positioned. The battery cable
terminal clamps must reach the correct battery ter-
minal post without stretching the cables (Fig. 17).
(3) Reinstall the battery hold downs onto the bat-
tery. Refer toBattery Hold Downsin this group for
the location of the proper battery hold down installa-
tion procedures.
CAUTION: Be certain that the battery cable terminal
clamps are connected to the correct battery termi-
nal posts. Reversed battery polarity may damage
electrical components of the vehicle.
Fig. 16 Remove Battery Cable Terminal Clamp -
Typical
1 - BATTERY
2 - BATTERY TERMINAL PULLER
Fig. 17 Battery Cables - Typical
1 - EYELET
2 - NUT
3 - POWER DISTRIBUTION CENTER
4 - POSITIVE CABLE
5 - SCREW
6 - NEGATIVE CABLE
7 - EYELET
8 - CLIP
BR/BEBATTERY SYSTEM 8F - 17
BATTERY (Continued)

(4) Clean the battery cable terminal clamps and
the battery terminal posts. Refer toBattery System
in this group for the location of the proper battery
system cleaning and inspection procedures.
(5) Reconnect the battery positive cable terminal
clamp to the battery positive terminal post. Tighten
the terminal clamp pinch-bolt hex nut to 4 N´m (35
in. lbs.).
(6) Reconnect the battery negative cable terminal
clamp to the battery negative terminal post. Tighten
the terminal clamp pinch-bolt hex nut to 4 N´m (35
in. lbs.).
(7) Apply a thin coating of petroleum jelly or chas-
sis grease to the exposed surfaces of the battery cable
terminal clamps and the battery terminal posts.
BATTERY HOLDDOWN
DESCRIPTION
The battery hold down hardware (Fig. 18) includes
two bolts, two U-nuts and a hold down strap. The bat-
tery hold down bracket consists of a formed steel rod
with a stamped steel angle bracket welded to each end.
The hold down bracket assembly is then plastic-coated
for corrosion protection. Models equipped with the
optional diesel engine have a second battery installed
in a second battery tray on the right side of the engine
compartment. The hold down hardware for the rightside battery is mirror image of the hold down hard-
ware used for the left side battery.
When installing a battery into the battery tray, be
certain that the hold down hardware is properly
installed and that the fasteners are tightened to the
proper specifications. Improper hold down fastener
tightness, whether too loose or too tight, can result in
damage to the battery, the vehicle or both. Refer to
Battery Hold Downsin this group for the location
of the proper battery hold down installation proce-
dures, including the proper hold down fastener tight-
ness specifications.
OPERATION
The battery holddown secures the battery in the
battery tray. This holddown is designed to prevent
battery movement during the most extreme vehicle
operation conditions. Periodic removel and lubrica-
tion of the battery holddown hardware is recomended
to prevent hardware seizure at a later date.
NOTE: Never operate a vehicle without a battery
holddown device properly installed. Damage to the
vehicle, components and battery could result.
REMOVAL
All of the battery hold down hardware except for
the outboard U-nut can be serviced without removal
of the battery or the battery tray. The battery tray
must be removed from the vehicle to service the out-
board U-nut. If the outboard U-nut requires service
replacement, refer toBattery Trayin the index of
this service manual for the location of the proper bat-
tery tray removal and installation procedures.
(1) Turn the ignition switch to the Off position. Be
certain that all electrical accessories are turned off.
(2) Loosen the battery negative cable terminal
clamp pinch-bolt hex nut.
(3) Disconnect the battery negative cable terminal
clamp from the battery negative terminal post. If
necessary, use a battery terminal puller to remove
the terminal clamp from the battery post.
(4) Remove the two battery hold down bolts from
the battery hold down strap (Fig. 19) .
(5) Remove the battery hold down strap from the
top of the battery case.
INSTALLATION
All of the battery hold down hardware except for
the outboard U-nut can be serviced without removal
of the battery or the battery tray. The battery tray
must be removed from the vehicle to service the out-
board U-nut. If the outboard U-nut requires service
replacement, refer toBattery Trayin the index of
this service manual for the location of the proper bat-
tery tray removal and installation procedures.
Fig. 18 Battery Hold Downs - Typical
1 - BATTERY TRAY
2 - U-NUT (2)
3 - BATTERY
4 - BOLT (2)
5 - STRAP
8F - 18 BATTERY SYSTEMBR/BE
BATTERY (Continued)

rosion or foreign material, then reassembled.
Following reassembly, check the voltage drop for the
battery cable connection and the battery cable again
to confirm repair.
When performing the voltage drop test, it is impor-
tant to remember that the voltage drop is giving an
indication of the resistance between the two points at
which the voltmeter probes are attached.EXAM-
PLE:When testing the resistance of the battery pos-
itive cable, touch the voltmeter leads to the battery
positive cable terminal clamp and to the battery pos-
itive cable eyelet terminal at the starter solenoid
B(+) terminal stud. If you probe the battery positive
terminal post and the battery positive cable eyelet
terminal at the starter solenoid B(+) terminal stud,
you are reading the combined voltage drop in the
battery positive cable terminal clamp-to-terminal
post connection and the battery positive cable.
VOLTAGE DROP TEST
WARNING: IF THE BATTERY SHOWS SIGNS OF
FREEZING, LEAKING, LOOSE POSTS, OR LOW
ELECTROLYTE LEVEL, 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.
WARNING: MODELS EQUIPPED WITH THE DIESEL
ENGINE OPTION ALSO HAVE AN AUTOMATIC
SHUTDOWN (ASD) RELAY LOCATED IN THE
POWER DISTRIBUTION CENTER (PDC), IN THE
ENGINE COMPARTMENT. HOWEVER, REMOVAL OFTHE ASD RELAY MAY NOT PREVENT THE DIESEL
ENGINE FROM STARTING. BE CERTAIN TO ALSO
DISCONNECT THE FUEL SHUTDOWN SOLENOID
WIRE HARNESS CONNECTOR ON MODELS WITH A
DIESEL ENGINE. FAILURE TO DO SO MAY RESULT
IN PERSONAL INJURY.
The following operation will require a voltmeter
accurate to 1/10 (0.10) volt. Before performing this
test, be certain that the following procedures are
accomplished:
²The battery is fully-charged and load tested.
Refer toBattery Chargingin the index of this ser-
vice manual for the location of the proper battery
charging procedures. Refer toBatteryin the index of
this service manual for the location of the battery
diagnosis and testing procedures, including the
proper battery load test procedures.
²Fully engage the parking brake.
²If the vehicle is equipped with an automatic
transmission, place the gearshift selector lever in the
Park position. If the vehicle is equipped with a man-
ual transmission, place the gearshift selector lever in
the Neutral position and block the clutch pedal in the
fully depressed position.
²Verify that all lamps and accessories are turned
off.
²To prevent a gasoline engine from starting,
remove the Automatic ShutDown (ASD) relay. The
ASD relay is located in the Power Distribution Cen-
ter (PDC), in the engine compartment. See the fuse
and relay layout label affixed to the underside of the
PDC cover for ASD relay identification and location.
To prevent a diesel engine from starting, disconnect
the fuel shutdown solenoid wire harness connector
(Fig. 21).
(1) Connect the positive lead of the voltmeter to
the battery negative terminal post. Connect the neg-
ative lead of the voltmeter to the battery negative
cable terminal clamp (Fig. 22). Rotate and hold the
ignition switch in the Start position. Observe the
voltmeter. If voltage is detected, correct the poor con-
nection between the battery negative cable terminal
clamp and the battery negative terminal post.
NOTE: If the vehicle is equipped with a dual battery
system, Step 1 must be performed twice, once for
each battery.
(2) Connect the positive lead of the voltmeter to
the battery positive terminal post. Connect the nega-
tive lead of the voltmeter to the battery positive cable
terminal clamp (Fig. 23). Rotate and hold the ignition
switch in the Start position. Observe the voltmeter. If
voltage is detected, correct the poor connection
between the battery positive cable terminal clamp
and the battery positive terminal post.
BR/BEBATTERY SYSTEM 8F - 21
BATTERY CABLE (Continued)

NOTE: If the vehicle is equipped with a dual battery
system, Step 2 must be performed twice, once for
each battery.(3) Connect the voltmeter to measure between the
battery positive cable terminal clamp and the starter
solenoid B(+) terminal stud (Fig. 24). Rotate and hold
the ignition switch in the Start position. Observe the
voltmeter. If the reading is above 0.2 volt, clean and
tighten the battery positive cable eyelet terminal con-
nection at the starter solenoid B(+) terminal stud.
Repeat the test. If the reading is still above 0.2 volt,
replace the faulty battery positive cable.
NOTE: If the vehicle is equipped with a dual battery
system, Step 3 must be performed on the driver
side battery only.
Fig. 21 Fuel Shutdown Solenoid Connector - Diesel
Engine
1 - AIR TEMPERATURE SENSOR
2 - SENSOR ELECTRICAL CONNECTOR
3 - SOLENOID ELECTRICAL CONNECTOR
4 - FUEL SHUTDOWN SOLENOID
5 - INTAKE MANIFOLD (UPPER HALF)
Fig. 22 Test Battery Negative Connection
Resistance - Typical
1 - VOLTMETER
2 - BATTERY
Fig. 23 Test Battery Positive Connection Resistance
- Typical
1 - VOLTMETER
2 - BATTERY
Fig. 24 Test Battery Positive Cable Resistance -
Typical
1 - BATTERY
2 - VOLTMETER
3 - STARTER MOTOR
8F - 22 BATTERY SYSTEMBR/BE
BATTERY CABLE (Continued)

(4) Connect the voltmeter to measure between the
battery negative cable terminal clamp and a good
clean ground on the engine block (Fig. 25). Rotate
and hold the ignition switch in the Start position.
Observe the voltmeter. If the reading is above 0.2
volt, clean and tighten the battery negative cable
eyelet terminal connection to the engine block.
Repeat the test. If the reading is still above 0.2 volt,
replace the faulty battery negative cable.
NOTE: If the vehicle is equipped with a dual battery
system, Step 4 must be performed twice, once for
each battery.
POSITIVE CABLE REMOVAL - GASOLINE
Both the battery negative cable and the battery
positive cable are serviced in the battery wire har-
ness. If either battery cable is damaged or faulty, the
battery wire harness assembly must be replaced.
(1) Remove the positive battery cable from the bat-
tery.
(2) Remove the cover from the PDC.
(3) Remove the positive battery cable from the
PDC.
(4) Disconnect the starter motor signal wire har-
ness connector, located on the PDC housing.
(5) Disengage wire harness assembly pushpin
retainers.
(6) From under the vehicle, disengage wire har-
ness assembly pushpin retainers.
(7) Remove the positive battery cable from the
starter motor B+ terminal stud.
(8) Remove the starter motor trigger wire from the
starter motor.
(9) Remove the positive cable wire harness assem-
bly from the vehicle.
NEGATIVE CABLE REMOVAL - GASOLINE
Both the battery negative cable and the battery
positive cable are serviced in the battery wire har-
ness. If either battery cable is damaged or faulty, the
battery wire harness unit must be replaced.
(1) Turn the ignition switch to the Off position. Be
certain that all electrical accessories are turned off.
(2) Loosen the battery negative cable terminal
clamp pinch-bolt hex nut.
(3) Disconnect the battery negative cable terminal
clamp from the battery negative terminal post. If
necessary, use a battery terminal puller to remove
the terminal clamp from the battery post.
(4) Remove the negative cable jumper from the left
side of the radiator closure panel.
(5) Remove the negative cable jumper from the left
side of the frame assembly.
(6) Remove the PDC cover and remove the gener-
ator output wire from the PDC.
(7) Following the wire, remove the pushpin retain-
ers holding the wire assembly in place.
(8) Remove the negative cable eyelet from the
power steering pump pivot bolt.
(9) Remove the generator output wire from the
generator.
(10) Remove the negative battery cable assembly,
by fishing out from under the compressor mounting
bracket, if equipped.
POSITIVE CABLE INSTALLATION - GASOLINE
(1) Position the battery wire harness into the
engine compartment.
(2) Install the positive battery cable on the battery.
(3) Install the positive battery cable on the PDC.
(4) Install the cover on the PDC.
(5) Connect the starter motor signal wire harness
connector, located on the PDC housing.
(6) Install wire harness assembly pushpin retain-
ers in their original position.
(7) From under the vehicle, install wire harness
assembly pushpin retainers.
(8) Install and tighten the nut that secures the
battery positive cable eyelet terminal to the B(+) ter-
minal stud on the starter solenoid. Tighten the nut to
10 N´m (90 in. lbs.).
(9) Connect the starter motor trigger wire on the
starter motor.
(10) Reconnect the battery positive cable terminal
clamp to the battery positive terminal post. Tighten
the terminal clamp pinch-bolt hex nut to 4 N´m (35
in. lbs.).
(11) Apply a thin coating of petroleum jelly or
chassis grease to the exposed surfaces of the battery
cable terminal clamps and the battery terminal
posts.
Fig. 25 Test Ground Circuit
1 - VOLTMETER
2 - BATTERY
3 - ENGINE GROUND
BR/BEBATTERY SYSTEM 8F - 23
BATTERY CABLE (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

STARTING
TABLE OF CONTENTS
page page
STARTING
DESCRIPTION...........................32
OPERATION.............................32
DIAGNOSIS AND TESTING.................33
STARTING SYSTEM.....................33
SPECIFICATIONS........................38
ENGINE STARTER MOTOR
DESCRIPTION...........................39
OPERATION.............................39
DIAGNOSIS AND TESTING.................39STARTERMOTOR......................39
REMOVAL..............................40
INSTALLATION...........................41
ENGINE STARTER MOTOR RELAY
DESCRIPTION...........................42
OPERATION.............................42
DIAGNOSIS AND TESTING.................42
STARTER RELAY.......................42
REMOVAL..............................43
INSTALLATION...........................43
STARTING
DESCRIPTION
The starting system consists of:
²Starter relay
²Starter motor (including an integral starter sole-
noid)
Other components to be considered as part of start-
ing system are:
²Battery
²Battery cables
²Ignition switch and key lock cylinder
²Clutch pedal position switch (manual transmis-
sion)
²Park/neutral position switch (automatic trans-
mission)
²Wire harnesses and connections.
The Battery, Starting, and Charging systems oper-
ate in conjunction with one another, and must be
tested as a complete system. For correct operation of
starting/charging systems, all components used in
these 3 systems must perform within specifications.
When attempting to diagnose any of these systems, it
is important that you keep their interdependency in
mind.
The diagnostic procedures used in each of these
groups include the most basic conventional diagnostic
methods, to the more sophisticated On-Board Diag-
nostics (OBD) built into the Powertrain Control Mod-
ule (PCM). Use of an induction-type milliampere
ammeter, volt/ohmmeter, battery charger, carbon pile
rheostat (load tester), and 12-volt test lamp may be
required.
Certain starting system components are monitored
by the PCM and may produce a Diagnostic Trouble
Code (DTC). Refer to Diagnostic Trouble Codes for
additional information and a list of codes.
OPERATION
The starting system components form two separate
circuits. A high-amperage feed circuit that feeds the
starter motor between 150 and 350 amperes (700
amperes - diesel engine), and a low-amperage control
circuit that operates on less than 20 amperes. The
high-amperage feed circuit components include the
battery, the battery cables, the contact disc portion of
the starter solenoid, and the starter motor. The low-
amperage control circuit components include the igni-
tion switch, the clutch pedal position switch (manual
transmission), the park/neutral position switch (auto-
matic transmission), the starter relay, the electro-
magnetic windings of the starter solenoid, and the
connecting wire harness components.
If the vehicle is equipped with a manual transmis-
sion, it has a clutch pedal position switch installed in
series between the ignition switch and the coil bat-
tery terminal of the starter relay. This normally open
switch prevents the starter relay from being ener-
gized when the ignition switch is turned to the
momentary Start position, unless the clutch pedal is
depressed. This feature prevents starter motor oper-
ation while the clutch disc and the flywheel are
engaged. The starter relay coil ground terminal is
always grounded on vehicles with a manual trans-
mission.
If the vehicle is equipped with an automatic trans-
mission, battery voltage is supplied through the low-
amperage control circuit to the coil battery terminal
of the starter relay when the ignition switch is
turned to the momentary Start position. The park/
neutral position switch is installed in series between
the starter relay coil ground terminal and ground.
This normally open switch prevents the starter relay
from being energized and the starter motor from
operating unless the automatic transmission gear
selector is in the Neutral or Park positions.
8F - 32 STARTINGBR/BE

When the starter relay coil is energized, the nor-
mally open relay contacts close. The relay contacts
connect the relay common feed terminal to the relay
normally open terminal. The closed relay contacts
energize the starter solenoid coil windings.
The energized solenoid pull-in coil pulls in the sole-
noid plunger. The solenoid plunger pulls the shift
lever in the starter motor. This engages the starter
overrunning clutch and pinion gear with the starter
ring gear on the manual transmission flywheel or on
the automatic transmission torque converter or
torque converter drive plate.
As the solenoid plunger reaches the end of its
travel, the solenoid contact disc completes the high-
amperage starter feed circuit and energizes the sole-
noid plunger hold-in coil. Current now flows between
the solenoid battery terminal and the starter motor,
energizing the starter.
Once the engine starts, the overrunning clutch pro-
tects the starter motor from damage by allowing the
starter pinion gear to spin faster than the pinionshaft. When the driver releases the ignition switch to
the On position, the starter relay coil is de-energized.
This causes the relay contacts to open. When the
relay contacts open, the starter solenoid plunger
hold-in coil is de-energized.
When the solenoid plunger hold-in coil is de-ener-
gized, the solenoid plunger return spring returns the
plunger to its relaxed position. This causes the con-
tact disc to open the starter feed circuit, and the shift
lever to disengage the overrunning clutch and pinion
gear from the starter ring gear.
DIAGNOSIS AND TESTING - STARTING
SYSTEM
The battery, starting, and charging systems oper-
ate in conjunction with one another, and must be
tested as a complete system. For correct starting/
charging system operation, all of the components
involved in these 3 systems must perform within
specifications.
Starting System Diagnosis
CONDITION POSSIBLE CAUSE CORRECTION
STARTER FAILS TO
OPERATE.1. Battery discharged or
faulty.1. Refer to Battery. Charge or replace battery, if required.
2. Starting circuit wiring
faulty.2. Refer to 8, Wiring Diagrams. Test and repair starter
feed and/or control circuits, if required.
3. Starter relay faulty. 3. Refer to Starter Relay in the Diagnosis and Testing
section of this group. Replace starter relay, if required.
4. Ignition switch faulty. 4. Refer to Ignition Switch and Key Lock Cylinder.
Replace ignition switch, if required.
5. Clutch pedal position
switch faulty.5. Refer to Clutch Pedal Position Switch.
6. Park/Neutral position
switch faulty or
misadjusted.6. Refer to Park/Neutral Position Switch. Replace
park/neutral position switch, if required.
7. Starter solenoid faulty. 7. Refer to Starter Motor. Replace starter motor assembly,
if required.
8. Starter motor faulty. 8. If all other starting system components and circuits test
OK, replace starter motor.
STARTER ENGAGES,
FAILS TO TURN
ENGINE.1. Battery discharged or
faulty.1. Refer to Battery. Charge or replace battery, if required.
2. Starting circuit wiring
faulty.2. Refer to 8, Wiring Diagrams. Test and repair starter
feed and/or control circuits, if required.
3. Starter motor faulty. 3. If all other starting system components and circuits test
OK, replace starter motor assembly.
4. Engine seized. 4. Refer to Engine Diagnosis in the Diagnosis and Testing
section of 9, Engine.
BR/BESTARTING 8F - 33
STARTING (Continued)

Starting System Diagnosis
CONDITION POSSIBLE CAUSE CORRECTION
STARTER ENGAGES,
SPINS OUT BEFORE
ENGINE STARTS.1. Starter ring gear faulty. 1. Refer to Starter Motor in Removal and Installation.
Remove starter motor to inspect starter ring gear.
Replace starter ring gear, if required.
2. Starter motor faulty. 2. If all other starting system components and circuits test
OK, replace the starter motor assembly.
STARTER DOES NOT
DISENGAGE.1. Starter motor
improperly installed.1. Refer to Starter Motor in the Removal and Installation
section of this group. Tighten the starter mounting
hardware to the correct tightness specifications.
2. Starter relay faulty. 2. Refer to Starter Relay in the Diagnosis and Testing
section of this group. Replace starter relay, if required.
3. Ignition switch faulty. 3. Refer to Ignition Switch and Key Lock Cylinder.
Replace ignition switch, if required.
4. Starter motor faulty. 4. If all other starting system components and circuits test
OK, replace starter motor.
INSPECTION
For complete starter wiring circuit diagrams, refer
to 8, Wiring Diagrams. Before removing any unit
from starting system for repair or diagnosis, perform
the following inspections:
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO 8, PASSIVE RESTRAINT SYS-
TEMS, BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT AND POSSIBLE PERSONAL INJURY.
²Battery- Visually inspect battery for indica-
tions of physical damage and loose or corroded cable
connections. Determine the state-of-charge and
cranking capacity of battery. Charge or replace bat-
tery, if required. Refer toBatteryin 8, Battery.
Note: If equipped with diesel engine, a dual bat-
tery system is used, and both batteries must be
inspected.
²Ignition Switch- Visually inspect ignition
switch for indications of physical damage and loose
or corroded wire harness connections. Refer toIgni-
tion Switch and Key Lock Cylinder.
²Clutch Pedal Position Switch- If equipped
with manual transmission, visually inspect clutch
pedal position switch for indications of physical dam-
age and loose or corroded wire harness connections.
Refer toClutch Pedal Position Switchin 6,
Clutch.
²Park/Neutral Position Switch- If equipped
with automatic transmission, visually inspect park/
neutral position switch for indications of physical
damage and loose or corroded wire harness connec-tions. Refer toPark/Neutral Position Switchin
21, Transmission.
²Starter Relay- Visually inspect starter relay
for indications of physical damage and loose or cor-
roded wire harness connections.
²Starter Motor- Visually inspect starter motor
for indications of physical damage and loose or cor-
roded wire harness connections.
²Starter Solenoid- Visually inspect starter sole-
noid for indications of physical damage and loose or
corroded wire harness connections.
²Wiring- Visually inspect wire harnesses for
damage. Repair or replace any faulty wiring, as
required. Refer to 8, Wiring Diagrams.
TESTING
COLD CRANKING TEST
For complete starter wiring circuit diagrams, refer
to 8, Wiring Diagrams. The battery must be fully-
charged and load-tested before proceeding. Refer to
Batteryin 8, Battery.
(1) Connect volt-ampere tester to battery terminals
(Fig. 1). See instructions provided by manufacturer of
volt-ampere tester being used.Note: If equipped
with dual battery system (diesel), tester should
be connected to driver side battery only. Also,
tester current reading must be taken from bat-
tery positive cable lead that connects to starter
motor.
(2) Fully engage parking brake.
(3) If equipped with manual transmission, place
gearshift selector lever in Neutral position and block
clutch pedal in fully depressed position. If equipped
with automatic transmission, place gearshift selector
lever in Park position.
8F - 34 STARTINGBR/BE
STARTING (Continued)