1998 DODGE RAM 1500 clutch

²Proper transmit/receive messages are occurring
on the PCI bus.
²Ignition key switch is in the RUN position.
Range shiftswill be allowed only if all of the fol-
lowing conditions are met:
²Front and rear wheel speed are within 21 km/hr
(13 mph).
²A change in the Selector Switch state indicating
a range shift has been requested.
²Transmission in NEUTRAL signal must be rec-
ognized for at least 1.5 seconds  100 msec. (Auto-
matic transmissions only)
²Proper transmit/receive messages are occurring
on the PCI bus.
²Clutch signal is recognized for 500 msec   50
msec (Manual transmissions only).
²Vehicle speed is less than or equal to 4.8 km/hr
(3 miles per hour).
²Ignition key switch is in the RUN position.
²A valid mode sensor signal is being sensed by
the TCCM.
Ashift into transfer case Neutralwill be
allowed only if all of the following conditions are met:
²Front and rear wheel speed are within 21 km/hr
(13 mph).
²The recessed Neutral Selection switch has been
depressed continuously for 4.0 seconds  100 msec
while all shift conditions have been continuously met.
²Transmission in NEUTRAL signal recognized
from the bus. (Automatic transmissions only)
²Clutch signal is recognized from the bus (Man-
ual transmissions only).
²Proper message transmissions/receptions are
occurring on the PCI bus.
²Vehicle speed is less than or equal to 4.8 km/hr
(3 miles per hour).
²Ignition key switch is in the RUN position,
engine off.
²Foot Brake is applied.
²A valid mode sensor signal is being sensed by
the TCCM.
Ashift out of transfer case Neutralwill be
allowed only if all of the following conditions are met:
²Front and rear wheel speed are within 21 km/hr
(13 mph).
²The recessed Neutral Selection switch has been
depressed continuously for 1.0 seconds  100 msec
while all shift conditions have been continuously met.
²Transmission in NEUTRAL signal recognized
from the bus.(Automatic transmissions only)
²Clutch signal is recognized from the bus (Man-
ual transmissions only).
²Proper message transmissions/receptions are
occurring on the PCI bus.
²Vehicle speed is less than or equal to 4.8 km/hr
(3 miles per hour).²Ignition key switch is in the RUN position.
²Foot Brake is applied.
²A valid mode sensor signal is being sensed by
the TCCM.
SHIFT SEQUENCES
Once all the driver controllable conditions for the
requested shift have been met, the TCCM begins a
shift timer with a maximum duration of 1 second per
'D' channel transition. If the shift timer expires
before the TCCM recognizes to correct mode sensor
code, the shift is considered to have been blocked.
The blocked shift will increment the blocked shift
counter by one. The TCCM strategy for handling
blocked shifts will be described later. The process the
TCCM performs for the various shifts will be
described first.
RANGE AND MODE SHIFTS
The process for performing all the range and mode
shifts are the same. The following steps describe the
process.
²Allow time for Selector Switch debounce; 250
msec  50 msec.
²Extinguish the source gear's LED while flashing
desired transfer case position's LED.
²Engage the shift motor for a maximum of 1 sec-
ond  100 msec per 'D' channel transition in the des-
tination gear's direction while monitoring the mode
sensor channel transitions.
²Disengage the shift motor when the correct
mode sensor code is recognized.
²Solidly illuminate the selected gear's LED.
²Transmit a bus message that the transfer case
shift is complete.
²If the desired mode sensor code is not received
after the shift timer expires (ie. a blocked or other
condition exists), stop driving the motor and wait for
200 msec  50 msec. The shift motor is then reversed
in the direction back toward the source gear for up to
1.0 seconds  100 msec. per 'D' channel. The TCCM
waits for 2.0 seconds  50 msec. and repeats the
attempt to shift to the desired position.
The exception to the preceding sequence is when a
shift from 4L to 2WD/AWD is requested. If 2WD/
AWD is requested from the 4L position, the transfer
case is first driven to the 4H position. If the 4H posi-
tion is reached, the transfer case is then driven back
to the 2WD/AWD position and the shift is considered
complete. If the transfer case does not reach any the
4H position, but is in the 2WD/AWD 'D' channel, or
the 2WD/AWD between gear position on the 4H side
of 2WD/AWD, the shift is also considered complete.
DRELECTRONIC CONTROL MODULES 8E - 17
TRANSFER CASE CONTROL MODULE (Continued)

TRANSMISSION CONTROL
MODULE
DESCRIPTION
The Transmission Control Module (TCM) (Fig. 9)
may be sub-module within the Powertrain Control
Module (PCM), Engine Control Module (ECM - Diesel
only) (Fig. 10), or a standalone module, depending on
the vehicle engine. The PCM, and TCM when
equipped, is located at the right rear of the engine
compartment, near the right inner fender.
OPERATION
The Transmission Control Module (TCM) controls
all electronic operations of the transmission. The
TCM receives information regarding vehicle opera-
tion from both direct and indirect inputs, and selects
the operational mode of the transmission. Direct
inputs are hardwired to, and used specifically by the
TCM. Indirect inputs are shared with the TCM via
the vehicle communication bus.
Some examples ofdirect inputsto the TCM are:
²Battery (B+) voltage
²Ignition ªONº voltage
²Transmission Control Relay (Switched B+)
²Throttle Position Sensor
²Crankshaft Position Sensor
²Transmission Range Sensor
²Pressure Switches
²Transmission Temperature Sensor
²Input Shaft Speed Sensor
²Output Shaft Speed Sensor
²Line Pressure Sensor
Some examples ofindirect inputsto the TCM
are:²Engine/Body Identification
²Manifold Pressure
²Target Idle
²Torque Reduction Confirmation
²Engine Coolant Temperature
²Ambient/Battery Temperature
²DRBIIItScan Tool Communication
Based on the information received from these var-
ious inputs, the TCM determines the appropriate
shift schedule and shift points, depending on the
present operating conditions and driver demand.
This is possible through the control of various direct
and indirect outputs.
Some examples of TCMdirect outputsare:
²Transmission Control Relay
²Solenoids
²Torque Reduction Request
Some examples of TCMindirect outputsare:
²Transmission Temperature (to PCM)
²PRNDL Position (to BCM)
In addition to monitoring inputs and controlling
outputs, the TCM has other important responsibili-
ties and functions:
²Storing and maintaining Clutch Volume Indexes
(CVI)
²Storing and selecting appropriate Shift Sched-
ules
²System self-diagnostics
Fig. 9 PCM/TCM Location
1 - RIGHT FENDER
2 - TRANSMISSION CONTROL MODULE
3 - POWERTRAIN CONTROL MODULE
Fig. 10 Diesel ECM
1 - ENGINE CONTROL MODULE (ECM)
2 - ECM MOUNTING BOLT
3 - 50-WAY CONNECTOR
4 - SUPPORT PLATE
5 - 60-WAY CONNECTOR
8E - 20 ELECTRONIC CONTROL MODULESDR

²Diagnostic capabilities (with DRBIIItscan tool)
NOTE: If the TCM has been replaced, the ªQuick
Learn Procedureº must be performed. (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MODULES/
TRANSMISSION CONTROL MODULE - STANDARD
PROCEDURE)
BATTERY FEED
A fused, direct battery feed to the TCM is used for
continuous power. This battery voltage is necessary
to retain memory in the TCM. When the battery (B+)
is disconnected, this memory is lost. When the bat-
tery (B+) is restored, this memory loss is detected by
the TCM and a Diagnostic Trouble Code (DTC) is set.
CLUTCH VOLUME INDEXES (CVI)
An important function of the TCM is to monitor
Clutch Volume Indexes (CVI). CVIs represent the vol-
ume of fluid needed to compress a clutch pack.
The TCM monitors gear ratio changes by monitor-
ing the Input and Output Speed Sensors. The Input,
or Turbine Speed Sensor sends an electrical signal to
the TCM that represents input shaft rpm. The Out-
put Speed Sensor provides the TCM with output
shaft speed information.
By comparing the two inputs, the TCM can deter-
mine transmission gear position. This is important to
the CVI calculation because the TCM determines
CVIs by monitoring how long it takes for a gear
change to occur (Fig. 11).
Gear ratios can be determined by using the
DRBIIItScan Tool and reading the Input/Output
Speed Sensor values in the ªMonitorsº display. Gear
ratio can be obtained by dividing the Input Speed
Sensor value by the Output Speed Sensor value.
For example, if the input shaft is rotating at 1000
rpm and the output shaft is rotating at 500 rpm,
then the TCM can determine that the gear ratio is
2:1. In direct drive (3rd gear), the gear ratio changes
to 1:1. The gear ratio changes as clutches are applied
and released. By monitoring the length of time it
takes for the gear ratio to change following a shift
request, the TCM can determine the volume of fluid
used to apply or release a friction element.
The volume of transmission fluid needed to apply
the friction elements are continuously updated for
adaptive controls. As friction material wears, the vol-
ume of fluid need to apply the element increases.
Certain mechanical problems within the input
clutch assembly can cause inadequate or out-of-rangeelement volumes. Also, defective Input/Output Speed
Sensors and wiring can cause these conditions. The
following chart identifies the appropriate clutch vol-
umes and when they are monitored/updated:
CLUTCH VOLUMES
Clutch When UpdatedProper Clutch
Volume
L/R2-1 or 3-1
downshift45 to 134
2C3-2 kickdown
shift25 to 85
OD 2-3 upshift 30 to 100
4C 3-4 upshift 30 to 85
UD4-3 kickdown
shift30 to 100
Fig. 11 Example of CVI Calculation
1 - OUTPUT SPEED SENSOR
2 - OUTPUT SHAFT
3 - CLUTCH PACK
4 - SEPARATOR PLATE
5 - FRICTION DISCS
6 - INPUT SHAFT
7 - INPUT SPEED SENSOR
8 - PISTON AND SEAL
DRELECTRONIC CONTROL MODULES 8E - 21
TRANSMISSION CONTROL MODULE (Continued)

STANDARD PROCEDURE
STANDARD PROCEDURE - TCM QUICK LEARN
The quick learn procedure requires the use of the
DRBtscan tool.
This program allows the electronic transmission
system to recalibrate itself. This will provide the
proper transmission operation. The quick learn pro-
cedure should be performed if any of the following
procedures are performed:
²Transmission Assembly Replacement
²Transmission Control Module Replacement
²Solenoid Pack Replacement
²Clutch Plate and/or Seal Replacement
²Valve Body Replacement or Recondition
To perform the Quick Learn Procedure, the follow-
ing conditions must be met:
²The brakes must be applied
²The engine speed must be above 500 rpm
²The throttle angle (TPS) must be less than 3
degrees
²The shift lever position must stay in PARK until
prompted to shift to overdrive
²The shift lever position must stay in overdrive
after the Shift to Overdrive prompt until the DRBt
indicates the procedure is complete
²The calculated oil temperature must be above
60É and below 200É
STANDARD PROCEDURE - DRIVE LEARN
When a transmission is repaired and a Quick
Learn procedure has been performed on the Trans-
mission Control Module (TCM), the following Drive
Learn procedure can be performed to fine tune any
shifts which are particularly objectionable.
NOTE: It is not necessary to perform the complete
Drive Learn procedure every time the TCM is Quick
Learned. Perform only the portions which target the
objectionable shift.
LEARN A SMOOTH 1ST NEUTRAL TO DRIVE SHIFT
Perform this procedure only if the complaint is for
a delayed or harsh shift the first time the transmis-
sion is put into gear after the vehicle is allowed to
set with the engine not running for at least 10 min-
utes. Use the following steps to have the TCM learn
the 1st N-D UD CVI.
NOTE: The transmission oil temperature must be
between 80 - 110ÉF (27 - 43ÉC).
(1) Start the engine only when the engine and
ignition have been off for at least ten (10) minutes.
(2) With the vehicle at a stop and the service
brake applied, record the 1st N-D UD CVI while per-forming a Neutral to Drive shift. The 1st N-D UD
CVI accounts for air entrapment in the UD clutch
that may occur after the engine has been off for a
period of time.
(3) Repeat Step 1 and Step 2 until the recorded 1st
N-D UD CVI value stabilizes.
NOTE: It is important that this procedure be per-
formed when the transmission temperature is
between 80 - 110ÉF (27 - 43ÉC). If this procedure
takes too long to complete fully for the allowed
transmission oil temperature, the vehicle may be
returned to the customer with an explanation that
the shift will improve daily during normal vehicle
usage. The TCM also learns at higher oil tempera-
tures, but these values (line pressure correction
values) are not available for viewing on the DRBT
III.
LEARN A SMOOTH NEUTRAL TO DRIVE GARAGE
SHIFT
Perform this procedure if the complaint is for a
delayed or harsh shift when the transmission is put
into gear after the vehicle has had its first shift. Use
the following steps to have the TCM learn the Norm
N-D UD CVI.
NOTE: The transmission oil temperature must be
between 80 - 110ÉF (27 - 43ÉC) to learn the UD CVI.
Additional learning occurs at temperatures as low
as 0ÉF and as high as 200ÉF. This procedure may be
performed at any temperature that experiences poor
shift quality. Although the UD CVI may not change,
shift quality should improve.
(1) Start the vehicle engine and shift to drive.
(2) Move the vehicle forward to a speed of at least
16 km/h (10 MPH) and come to a stop. This ensures
no air is present in the UD hydraulic circuit.
(3) Perform repeated N-D shifts at a stop while
pausing in Neutral for at least 2-3 seconds and mon-
itor Norm N-D UD CVI volume until the value stabi-
lizes. The value will change during the N-D shift.
This is normal since the UD value is different for the
N-D shift then the normal value shown which is used
for 4-3 coastdown and kickdowns. Perform repeated
shifts in this temperature range until the Norm N-D
UD CVI value stabilizes and the N-D shifts become
smooth.
LEARN THE 1ST 2-3 SHIFT AFTER A RESTART OR
SHIFT TO REVERSE
Use the following steps to have the TCM learn the
1st 2-3 shift OD CVI.
DRELECTRONIC CONTROL MODULES 8E - 23
TRANSMISSION CONTROL MODULE (Continued)

NOTE: The transmission oil temperature must be
above 80ÉF (27ÉC).
(1) With the vehicle engine running, select reverse
gear for over 2 seconds.
(2) Shift the transmission to Drive and accelerate
the vehicle from a stop at a steady 15 degree throttle
opening and perform a 2-3 shift while noting the 1st
2-3 OD CVI.
(3) Repeat Step 1 and Step 2 until the 1st 2-3
upshift becomes smooth and the 1st 2-3 OD CVI sta-
bilizes.
LEARN A SMOOTH 2-3 AND 3-4 UPSHIFT
NOTE: The transmission oil temperature must be
above 110ÉF (43ÉC).
Use the following steps to have the TCM learn the
OD and 4C CVI's.
(1) Accelerate the vehicle from a stop at a steady
15 degree throttle opening and perform multiple 1-2,
2-3, and 3-4 upshifts. The 2nd 2-3 shift following a
restart or shift to reverse will be shown during the
shift as a value between the 1st 2-3 OD CVI and the
normal OD CVI. Updates to the normal OD CVI will
occur after the 2nd shift into 3rd gear, following a
restart or shift to reverse.
(2) Repeat Step 1 until the 2-3 and 3-4 shifts
become smooth and the OD and 4C CVI become sta-
ble.
LEARN A SMOOTH 4-3 COASTDOWN AND PART
THROTTLE 4-3 KICKDOWN
NOTE: The transmission oil temperature must be
above 110ÉF (43ÉC).
Use the following steps to have the TCM learn the
UD shift volume.
(1) At a vehicle speed between 64-97 km/h (40-60
MPH), perform repeated 4-3 kickdown shifts.
(2) Repeat Step 1 until the UD volume becomes
somewhat stable and the shift becomes smooth.
LEARN A SMOOTH 1-2 UPSHIFT AND 3-2
KICKDOWN
Use the following steps to have the TCM learn the
2C shift volume.
NOTE: The transmission oil temperature must be
above 110ÉF (43ÉC).(1) With a vehicle speed below 48 km/h (30 MPH)
and the transmission in 3rd gear, perform multiple
3-2 kickdowns.
(2) Repeat Step 1 until the 3-2 kickdowns become
smooth and the 2C CVI becomes stable.
LEARN A SMOOTH MANUAL 2-1 PULLDOWN
SHIFT AS WELL AS A NEUTRAL TO REVERSE
SHIFT
NOTE: The transmission oil temperature must be
above 110ÉF (43ÉC).
Use the following steps to have the TCM learn the
LR volume.
(1) With the vehicle speed around 40-48 km/h
(25-30 MPH) in Manual 2nd, perform manual pull-
downs to Low or 1st gear at closed throttle.
(2) Repeat Step 1 until the LR CVI becomes stable
and the manual 2-1 becomes smooth.
LEARN A SMOOTH NEUTRAL TO REVERSE SHIFT
NOTE: The transmission oil temperature must be
above 110ÉF (43ÉC).
(1) With the vehicle at a stop, perform Neutral to
Reverse shifts until the shift is smooth. An unlearned
Neutral to Reverse shift may be harsh or exhibit a
double bump.
(2) If any of the shifts are still not smooth after
the clutch volume stabilizes, an internal transmis-
sion problem may be present.
LEARN A SMOOTH 4-5 UPSHIFT
NOTE: The transmission oil temperature must be
above 110ÉF (43ÉC).
Use the following steps to have the TCM learn the
Alt 2C CVI.
(1) Accelerate the vehicle through 88 km/h
(55mph) at a steady 10-15 degree throttle opening
and perform multiple 4-5 upshifts.
(2) Repeat Step 1 until the 4-5 shift become
smooth and theAlt 2C CVI become stable. There is a
separate 2C volume used and learned for 4-5 shifts,
2CA. It is independent of the 2C CVI learned on 3-2
kickdowns.
8E - 24 ELECTRONIC CONTROL MODULESDR
TRANSMISSION CONTROL MODULE (Continued)

Large eyelet type terminals are crimped onto the
opposite end of the battery cable wire and then sol-
der-dipped. The battery positive cable wires have a
red insulating jacket to provide visual identification
and feature a larger female battery terminal clamp
to allow connection to the larger battery positive ter-
minal post. The battery negative cable wires have a
black insulating jacket and a smaller female battery
terminal clamp.
OPERATION
The battery cables connect the battery terminal
posts to the vehicle electrical system. These cables
also provide a return path for electrical current gen-
erated by the charging system for restoring the volt-
age potential of the battery. The female battery
terminal clamps on the ends of the battery cable
wires provide a strong and reliable connection of the
battery cable to the battery terminal posts. The ter-
minal pinch bolts allow the female terminal clamps
to be tightened around the male terminal posts on
the top of the battery. The eyelet terminals secured
to the ends of the battery cable wires opposite the
female battery terminal clamps provide secure and
reliable connection of the battery to the vehicle elec-
trical system.
DIAGNOSIS AND TESTING - BATTERY CABLES
A voltage drop test will determine if there is exces-
sive resistance in the battery cable terminal connec-
tions or the battery cables. If excessive resistance is
found in the battery cable connections, the connec-
tion point should be disassembled, cleaned of all cor-
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: MODELS EQUIPPED WITH A DIESEL
ENGINE HAVE AN AUTOMATIC SHUTDOWN (ASD)RELAY LOCATED IN THE POWER DISTRIBUTION
CENTER (PDC). REMOVAL OF THE ASD RELAY
MAY NOT PREVENT THE DIESEL ENGINE FROM
STARTING. BE CERTAIN TO DISCONNECT THE
FUEL SHUTDOWN SOLENOID WIRE HARNESS
CONNECTOR TO PREVENT THE ENGINE FROM
STARTING. 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 tested (Refer to
8 - ELECTRICAL/BATTERY SYSTEM/BATTERY -
STANDARD PROCEDURE).
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 Integrated Power Module
(IPM), in the engine compartment. See the fuse and
relay layout label on the underside of the IPM cover
for ASD relay identification and location.
(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. 11). 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 two 12v bat-
teries, 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. 12). 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.
NOTE: If the vehicle is equipped with two 12v bat-
teries, step #2 must be performed twice, once for
each battery.
DRBATTERY SYSTEM 8F - 15
BATTERY CABLES (Continued)

STARTING
TABLE OF CONTENTS
page page
STARTING
DESCRIPTION.........................26
OPERATION...........................26
DIAGNOSIS AND TESTING - STARTING
SYSTEM............................27
SPECIFICATIONS
STARTING SYSTEM...................31
SPECIFICATIONS - TORQUE - STARTING
SYSTEM............................32
STARTER MOTOR
DIAGNOSIS AND TESTING - STARTER
MOTOR .............................32REMOVAL.............................33
INSTALLATION.........................34
STARTER MOTOR RELAY
DESCRIPTION.........................35
OPERATION...........................36
DIAGNOSIS AND TESTING - STARTER RELAY . 36
REMOVAL.............................37
INSTALLATION.........................37
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 in
Emission Control for 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 Start
position, unless the clutch pedal is depressed. This
feature prevents starter motor operation while the
clutch disc and the flywheel are engaged. The starter
relay coil ground terminal is always grounded on
vehicles with a manual transmission.
8F - 26 STARTINGDR

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 Start position. The park/neutral posi-
tion 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.
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.
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 pinion
shaft. When the ignition switch is released 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 Diagnosis and Testing.
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.
DRSTARTING 8F - 27
STARTING (Continued)