1998 DODGE RAM 1500 Electronic control module

SIDE IMPACT SENSOR
DESCRIPTION
On vehicles equipped with the optional side curtain
airbags, two side impact sensors are used, one each
for the left and right sides of the vehicle (Fig. 54).
These sensors are mounted remotely from the bi-di-
rectional safing sensor that is internal to the Airbag
Control Module (ACM). The side impact sensors are
secured within the right and left B-pillars just above
the front seat belt retractors and behind the lower
B-pillar trim in the passenger compartment.
The impact sensor housing has an integral connec-
tor receptacle, an integral mounting stud, and an
integral locating tab. A cavity in the center of the
molded black plastic impact sensor housing contains
the electronic circuitry of the sensor, which includes
an electronic communication chip and an electronic
impact sensor. Potting material fills the cavity to seal
and protect the internal electronic circuitry and com-
ponents. The side impact sensors are each connected
to the vehicle electrical system through a dedicated
take out and connector of the body wire harness.
The side impact sensors cannot be repaired or
adjusted and, if damaged or faulty, they must be
replaced.
OPERATION
The side impact sensors are electronic accelerome-
ters that sense the rate of vehicle deceleration, which
provides verification of the direction and severity of
an impact. Each sensor also contains an electronic
communication chip that allows the unit to commu-
nicate the sensor status as well as sensor fault infor-
mation to the microprocessor in the Airbag Control
Module (ACM). The ACM microprocessor continu-
ously monitors all of the passive restraint system
electrical circuits to determine the system readiness.
If the ACM detects a monitored system fault, it sets
a Diagnostic Trouble Code (DTC) and controls the
airbag indicator operation accordingly.
The impact sensors each receive battery current
and ground through dedicated left and right sensor
plus and minus circuits from the ACM. The impact
sensors and the ACM communicate by modulating
the voltage in the sensor plus circuit. The hard wired
circuits between the side impact sensors and the
ACM may be diagnosed and tested using conven-
tional diagnostic tools and procedures. However, con-
ventional diagnostic methods will not prove
conclusive in the diagnosis of the ACM or the impact
sensors. The most reliable, efficient, and accurate
means to diagnose the impact sensors, the ACM, and
the electronic message communication between the
sensors and the ACM requires the use of a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
REMOVAL
REMOVAL - STANDARD CAB
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
Fig. 54 Side Impact Sensor
1 - SENSOR
2 - CONNECTOR RECEPTACLE
3 - STUD
DRRESTRAINTS 8O - 59

SPEED CONTROL
TABLE OF CONTENTS
page page
SPEED CONTROL
DESCRIPTION..........................1
OPERATION............................2
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - VACUUM
SUPPLY TEST.........................2
DIAGNOSIS AND TESTING - ROAD TEST....3
SPECIFICATIONS
TORQUE - SPEED CONTROL.............3
CABLE
DESCRIPTION..........................4
OPERATION............................4
REMOVAL.............................4
INSTALLATION..........................5
SERVO
DESCRIPTION..........................6OPERATION............................6
REMOVAL.............................6
INSTALLATION..........................6
SWITCH
DESCRIPTION..........................7
OPERATION............................7
REMOVAL.............................8
INSTALLATION..........................8
VACUUM RESERVOIR
DESCRIPTION..........................9
OPERATION............................9
DIAGNOSIS AND TESTING - VACUUM
RESERVOIR..........................9
REMOVAL.............................9
INSTALLATION.........................10
SPEED CONTROL
DESCRIPTION
All 3.7L/4.7LGas Engines and/or Diesel With
Automatic Trans.
The speed control system is operated by the use of
a cable and a vacuum controlled servo. On all
engines except diesels, electronic control of the speed
control system is integrated into the Powertrain Con-
trol Module (PCM). If equipped with a diesel engine,
electronic control of the speed control system is inte-
grated into the Engine Control Module (ECM). The
controls consist of two steering wheel mounted
switches. The switches are labeled: ON/OFF, RES/
ACCEL, SET, COAST, and CANCEL.
The system is designed to operate at speeds above
30 mph (50 km/h).
WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS IN HEAVY TRAFFIC OR ON ROADS THAT
ARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.
5.7L Gas
The speed control system is fully electronically con-
trolled by the Powertrain Control Module (PCM).A
cable and a vacuum controlled servo are not
used. This is a servo-less system.The controls
consist of two steering wheel mounted switches. The
switches are labeled: ON/OFF, RES/ACCEL, SET,
COAST, and CANCEL.
The system is designed to operate at speeds above
30 mph (50 km/h).
WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS IN HEAVY TRAFFIC OR ON ROADS THAT
ARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.
DRSPEED CONTROL 8P - 1

5.9L Diesel With Manual Trans.
The speed control system is fully electronically con-
trolled by the Engine Control Module (ECM).A
cable and a vacuum controlled servo are not
used if the vehicle is equipped with a manual
transmission and a diesel engine. This is a ser-
vo-less system.The controls consist of two steering
wheel mounted switches. The switches are labeled:
ON/OFF, RES/ACCEL, SET, COAST, and CANCEL.
The system is designed to operate at speeds above
30 mph (50 km/h).
WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS IN HEAVY TRAFFIC OR ON ROADS THAT
ARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.
OPERATION
When speed control is selected by depressing the
ON switch, the PCM (the ECM with a diesel engine)
allows a set speed to be stored in its RAM for speed
control. To store a set speed, depress the SET switch
while the vehicle is moving at a speed between 35
and 85 mph. In order for the speed control to engage,
the brakes cannot be applied, nor can the gear selec-
tor be indicating the transmission is in Park or Neu-
tral.
The speed control can be disengaged manually by:
²Stepping on the brake pedal
²Depressing the OFF switch
²Depressing the CANCEL switch.
²Depressing the clutch pedal (if equipped).
NOTE: Depressing the OFF switch or turning off the
ignition switch will erase the set speed stored in
the PCM (the ECM with a diesel engine).
For added safety, the speed control system is pro-
grammed to disengage for any of the following condi-
tions:
²An indication of Park or Neutral
²A rapid increase rpm (indicates that the clutch
has been disengaged)
²Excessive engine rpm (indicates that the trans-
mission may be in a low gear)
²The speed signal increases at a rate of 10 mph
per second (indicates that the coefficient of friction
between the road surface and tires is extremely low)
²The speed signal decreases at a rate of 10 mph
per second (indicates that the vehicle may have
decelerated at an extremely high rate)Once the speed control has been disengaged,
depressing the RES/ACCEL switch (when speed is
greater than 30 mph) restores the vehicle to the tar-
get speed that was stored in the PCM (the ECM with
a diesel engine).
While the speed control is engaged, the driver can
increase the vehicle speed by depressing the RES/AC-
CEL switch. The new target speed is stored in the
PCM (the ECM with a diesel engine) when the RES/
ACCEL is released. The PCM (the ECM with a diesel
engine) also has a9tap-up9feature in which vehicle
speed increases at a rate of approximately 2 mph for
each momentary switch activation of the RES/AC-
CEL switch.
A ªtap downº feature is used to decelerate without
disengaging the speed control system. To decelerate
from an existing recorded target speed, momentarily
depress the COAST switch. For each switch activa-
tion, speed will be lowered approximately 1 mph.DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - VACUUM SUPPLY
TEST
3.7L / 4.7L Gas Powered Engines
3.7L/4.7L gas powered engines: actual engine vac-
uum, a vacuum reservoir, a one-way check valve and
vacuum lines are used to supply vacuum to the speed
control servo.
(1) Disconnect vacuum hose at speed control servo
and install a vacuum gauge into the disconnected
hose.
(2) Start engine and observe gauge at idle. Vac-
uum gauge should read at least ten inches of mer-
cury.
(3) If vacuum is less than ten inches of mercury,
determine source of leak. Check vacuum line to
engine for leaks. Also check actual engine intake
manifold vacuum. If manifold vacuum does not meet
this requirement, check for poor engine performance
and repair as necessary.
(4) If vacuum line to engine is not leaking, check
for leak at vacuum reservoir. To locate and gain
access to reservoir, refer to Vacuum Reservoir Remov-
al/Installation in this group. Disconnect vacuum line
at reservoir and connect a hand-operated vacuum
pump to reservoir fitting. Apply vacuum. Reservoir
vacuum should not bleed off. If vacuum is being lost,
replace reservoir.
8P - 2 SPEED CONTROLDR
SPEED CONTROL (Continued)

VEHICLE THEFT SECURITY
TABLE OF CONTENTS
page page
VEHICLE THEFT SECURITY
DESCRIPTION
DESCRIPTION - VEHICLE THEFT/
SECURITY SYSTEM....................1
DESCRIPTION - SENTRY KEY
IMMOBILIZER SYSTEM (SKIS)............1
DESCRIPTION ± SENTRY KEY
IMMOBILIZER MODULE (SKIM)............1
OPERATION
OPERATION - VEHICLE THEFT/SECURITY
SYSTEM.............................1
OPERATION - SENTRY KEY IMMOBILIZER
SYSTEM (SKIS)........................2
OPERATION ± SENTRY KEY IMMOBILIZER
MODULE (SKIM).......................2DIAGNOSIS AND TESTING
VEHICLE THEFT SECURITY SYSTEM......3
STANDARD PROCEDURE
CONFIGURING A NEW MODULE / SWITCH
OPERATING MODES....................3
SENTRY KEY IMMOBILIZER SYSTEM
INITIALIZATION........................3
SENTRY KEY IMMOBILIZER SYSTEM
TRANSPONDER PROGRAMMING..........4
SENTRY KEY IMMOBILIZER SYSTEM
INDICATOR LAMP
DESCRIPTION..........................5
OPERATION............................5
VEHICLE THEFT SECURITY
DESCRIPTION
DESCRIPTION - VEHICLE THEFT/SECURITY
SYSTEM
The Vehicle Theft/Security System (VTSS) is
designed to protect against whole vehicle theft. The
system monitors the vehicle doors and ignition for
unauthorized operation.
The VTSS activates:
²Sounding of the horn
²Flashing of the park lamps
²Flashing of the head lamps
The Remote Keyless Entry (RKE) has 1 mode of
operation,CUSTOMER USAGEmode. The cus-
tomer usage mode provides full functionality of the
module and is the mode in which the RKE module
should be operating when used by the customer.
DESCRIPTION - SENTRY KEY IMMOBILIZER
SYSTEM (SKIS)
The Sentry Key Immobilizer System (SKIS) is
designed to provide passive protection against unau-
thorized vehicle use by preventing the engine from
operating while the system is armed. The primary
components of this system are the Sentry Key Immo-
bilizer Module (SKIM), the Sentry Key transponder,
the Vehicle Theft/Security System (VTSS) indicator
LED, and the Powertrain Control Module (PCM).The SKIM is installed on the steering column near
the ignition lock cylinder. The transponder is located
under the molded rubber cap on the head of the igni-
tion key. The VTSS indicator LED is located in the
instrument cluster.
DESCRIPTION ± SENTRY KEY IMMOBILIZER
MODULE (SKIM)
The Sentry Key Immobilizer Module (SKIM) con-
tains a Radio Frequency (RF) transceiver and a cen-
tral processing unit, which includes the Sentry Key
Immobilizer System (SKIS) program logic. The SKIS
programming enables the SKIM to program and
retain in memory the codes of at least two, but no
more than eight electronically coded Sentry Key
transponders. The SKIS programming also enables
the SKIM to communicate over the Programmable
Communication Interface (PCI) bus network with the
Powertrain Control Module (PCM), and/or the
DRBIIItscan tool.
OPERATION
OPERATION - VEHICLE THEFT/SECURITY
SYSTEM
When in theCustomer Usagemode of operation,
the system is armed when the vehicle is locked using
the:
²Power Door Lock Switches
²Remote Keyless Entry (RKE) Transmitter
²Key Cylinder Switches
DRVEHICLE THEFT SECURITY 8Q - 1

SKIM cannot be repaired and, if faulty or damaged,
the unit must be replaced.
DIAGNOSIS AND TESTING
VEHICLE THEFT SECURITY SYSTEM
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO RESTRAINT SYSTEMS BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
NOTE: The most reliable, efficient, and accurate
means to diagnose the Vehicle Theft Security Sys-
tem (VTSS) and Sentry Key Immobilizer System
(SKIS) involves the use of a DRBlllTscan tool and
the proper Powertrain Diagnostic Procedures man-
ual.
The Vehicle Theft Security System (VTSS), Sentry
Key Immobilizer System (SKIS) and the Programma-
ble Communication Interface (PCI) bus network
should be diagnosed using a DRBIIItscan tool. The
DRBIIItwill allow confirmation that the PCI bus is
functional, that the Sentry Key Immobilizer Module
(SKIM) is placing the proper messages on the PCI
bus, and that the Powertrain Control Module (PCM)
and the Instrument Cluster are receiving the PCI
bus messages. Refer to the proper Powertrain or
Body Diagnostic Procedures manual.
Visually inspect the related wiring harness connec-
tors. Look for broken, bent, pushed out or corroded
terminals. If any of the conditions are present, repair
as necessary. Refer to Wiring Diagrams for complete
circuit descriptions and diagrams. Refer to 8 - ELEC-
TRICAL/ELECTRONIC CONTROL MODULES/SEN-
TRY KEY IMMOBILIZER MODULE - REMOVAL for
SKIM replacement.
STANDARD PROCEDURE
CONFIGURING A NEW MODULE / SWITCH
OPERATING MODES
To configure a new module or to switch operating
modes, a DRBIIItscan tool must be used.
(1) Hook up the DRBIIItscan tool to the Data
Link Connector (DLC).
(2) With the key in the ignition, turn the key to
the RUN position.(3) After the DRBIIItscan tool initialization, per-
form the following:
(a) Select ªTheft Alarm.º
(b) Select ªVTSS.º
(c) Select ªMiscellaneous.º
(4) Once in the ªMiscellaneousº screen:
(a) If you wish to configure a new module, select
ªConfigure Module.º
(b) If you wish to put the module into customer
usage mode, select ªEnable VTSS.º
(c) If you wish to put the module into dealer lot
mode, select ªDealer Lot.º
SENTRY KEY IMMOBILIZER SYSTEM
INITIALIZATION
The Sentry Key Immobilizer System (SKIS) initial-
ization should be performed following a Sentry Key
Immobilizer Module (SKIM) replacement.
It can be summarized by the following:
(1) Obtain the vehicles unique PIN number
assigned to it's original SKIM from the vehicle
owner, the vehicle's invoice or from Chrysler's Cus-
tomer Center.
(2) With the DRBIIItscan tool, select ªTheft
Alarm,º ªSKIM,º Miscellaneous.º Select ªSKIM Mod-
ule Replacedº function and the DRBIIItwill prompt
you through the following steps.
(3) Enter secured access mode using the unique
four digit PIN number.
(4) Program the vehicle's VIN number into the
SKIM's memory.
(5) Program the country code into the SKIM's
memory (U.S.).
(6) Transfer the vehicle's unique Secret Key data
from the PCM. This process will require the SKIM to
be insecured access mode. The PIN number must
be entered into the DRBIIItbefore the SKIM will
entersecured access mode. Oncesecured access
modeis active, the SKIM will remain in that mode
for 60 seconds.
(7) Program all customer keys into the SKIM's
memory. This required that the SKIM be insecured
access modeThe SKIM will immediately exit
secured access modeafter each key is pro-
grammed.
NOTE: If a PCM is replaced, the unique ªSecret
Keyº data must be transferred from the SKIM to the
PCM. This procedure requires the SKIM to be
placed in SECURED ACCESS MODE using the four
digit PIN code.
DRVEHICLE THEFT SECURITY 8Q - 3
VEHICLE THEFT SECURITY (Continued)

is released before parking the wiper blades near the
base of the windshield. If the control knob is held in
the depressed Wash position for more than about
thirty seconds, washer system operation will be sus-
pended until the control knob is released for about
two seconds then cycled back to the Wash position.
OPERATION
The wiper and washer system is designed to pro-
vide the vehicle operator with a convenient, safe, and
reliable means of maintaining visibility through the
windshield glass. The various components of this sys-
tem are designed to convert electrical energy pro-
duced by the vehicle electrical system into the
mechanical action of the wiper blades to wipe the
outside surface of the glass, as well as into the
hydraulic action of the washer system to apply
washer fluid stored in an on-board reservoir to the
area of the glass to be wiped. When combined, these
components provide the means to effectively main-
tain clear visibility for the vehicle operator by remov-
ing excess accumulations of rain, snow, bugs, mud, or
other minor debris from the outside windshield glass
surface that might be encountered while driving the
vehicle under numerous types of inclement operating
conditions.
The vehicle operator initiates all wiper and washer
system functions with the control knob on the end of
the control stalk of the multi-function switch that
extends from the left side of the steering column, just
below the steering wheel. Rotating the control knob
on the end of the control stalk, selects the Off, Delay,
Low, or High wiper system operating modes. In the
Delay mode, the control knob also allows the vehicle
operator to select from one of five intermittent wipe
Delay intervals. Depressing the control knob towards
the steering column actuates the momentary washer
system switch, which selects the Wash, Wipe-After-
Wash, and Pulse Wipe Modes depending upon when
and how long the switch is held closed. The multi-
function switch provides hard wired resistor multi-
plexed inputs to the instrument cluster for all of the
wiper and washer system functions. The instrument
cluster then sends electronic messages to the Front
Control Module (FCM) over the Programmable Com-
munications Interface (PCI) data bus requesting the
appropriate wiper and washer system operating
modes.
Wiper and washer system operation are completely
controlled by the instrument cluster and FCM logic
circuits, and that logic will only allow these systems
to operate when the ignition switch is in the Acces-
sory or On positions. Battery current is directed from
a B(+) fuse in the Integrated Power Module (IPM) to
the wiper on/off relay and the wiper high/low relay in
the IPM through a fused B(+) circuit. The FCM useslow side drivers to control wiper system operation by
energizing or de-energizing the wiper high/low and
wiper on/off relays. The FCM uses a high side driver
to control the operation of the washer pump motor
unit. The multi-function switch circuitry receives a
clean ground output from the instrument cluster on a
multi-function switch return circuit, then provides
resistor multiplexed inputs to the instrument cluster
on an intermittent wipe mux circuit to indicate the
selected wiper system mode and on a wash/beam
select mux circuit to indicate the selected washer sys-
tem mode.
The hard wired circuits and components of the
wiper and washer system may be diagnosed and
tested using conventional diagnostic tools and proce-
dures. However, conventional diagnostic methods
may not prove conclusive in the diagnosis of the
instrument cluster, the FCM, or the electronic mes-
sage inputs to or outputs from the instrument cluster
or FCM that control the wiper and washer system
operating modes. The most reliable, efficient, and
accurate means to diagnose the instrument cluster or
the FCM inputs and outputs related to the various
wiper and washer system operating modes requires
the use of a DRBIIItscan tool. Refer to the appro-
priate diagnostic information.
OPERATING MODES
Following are paragraphs that briefly describe the
operation of each of the wiper and washer system
operating modes.
CONTINUOUS WIPE MODE
When the Low position of the control knob on the
control stalk of the multi-function switch is selected
the instrument cluster sends an electronic wiper
switch low message to the FCM, then the FCM ener-
gizes the wiper on/off relay. This directs battery cur-
rent through the normally open contacts of the
energized wiper on/off relay and the normally closed
contacts of the de-energized wiper high/low relay to
the low speed brush of the wiper motor, causing the
wipers to cycle at low speed.
When the High position of the control knob is
selected the instrument cluster sends an electronic
wiper switch high message to the FCM, then the
FCM energizes both the wiper on/off relay and the
wiper high/low relay. This directs battery current
through the normally open contacts of the energized
wiper on/off relay and the normally open contacts of
the energized wiper high/low relay to the high speed
brush of the wiper motor, causing the wipers to cycle
at high speed.
When the Off position of the multi-function switch
control knob is selected, the instrument cluster sends
an electronic wiper switch off message to the FCM. If
8R - 4 WIPERS/WASHERSDR
WIPERS/WASHERS (Continued)

the wiper motor was operating at high speed, the
FCM immediately de-energizes the wiper high/low
relay causing the wiper motor to return to low speed
operation. Then one of two events will occur. The
event that occurs depends upon the position of the
wiper blades on the windshield at the moment that
the control knob Off position is selected.
If the wiper blades are in the down position on the
windshield when the Off position is selected, the
park switch that is integral to the wiper motor is
closed to ground and provides a hard wired park
switch sense input to the FCM. The FCM then de-en-
ergizes the wiper on/off relay and the wiper motor
ceases to operate. If the wiper blades are not in the
down position on the windshield at the moment the
Off position is selected, the park switch is an open
circuit and the FCM keeps the wiper on/off relay
energized, which causes the wiper motor to continue
running at low speed until the wiper blades are in
the down position on the windshield and the park
switch input to the FCM is again closed to ground.
INTERMITTENT WIPE MODE
When the control knob on the control stalk of the
multi-function switch is moved to one of the Delay
interval positions the instrument cluster sends an
electronic wiper switch delay message to the FCM,
then the FCM electronic intermittent wipe logic cir-
cuit responds by calculating the correct length of
time between wiper sweeps based upon the selected
delay interval input. The FCM monitors the changing
state of the wiper motor park switch through a hard
wired park switch sense input. This input allows the
FCM to determine the proper intervals at which to
energize and de-energize the wiper on/off relay to
operate the wiper motor intermittently for one low
speed cycle at a time.
The FCM logic is also programmed to provide vehi-
cle speed sensitivity to the selected intermittent wipe
delay intervals. In order to provide this feature the
FCM monitors electronic vehicle speed messages
from the Powertrain Control Module (PCM) and dou-
bles the selected delay interval whenever the vehicle
speed is about sixteen kilometers-per-hour (ten miles-
per-hour) or less.
PULSE WIPE MODE
When the control knob on the control stalk of the
multi-function switch is depressed to the momentary
Wash position for less than about one-half second,
the instrument cluster sends an electronic washer
switch message to the FCM, then the FCM the ener-
gizes the wiper on/off relay for one complete wipe
cycle. The FCM de-energizes the relay when the state
of the park switch sense changes to ground, parking
the wiper blades near the base of the windshield.WASH MODE
When the control knob on the control stalk of the
multi-function switch is depressed to the momentary
Wash position for more than about one-half second,
the instrument cluster sends an electronic washer
switch message to the FCM, then the FCM directs
battery current to the washer pump/motor unit. This
will cause the washer pump/motor unit to be ener-
gized for as long as the Wash switch is held closed up
to about thirty seconds, and to de-energize when the
front Wash switch is released.
When the control knob is depressed to the momen-
tary Wash position while the wiper system is operat-
ing in one of the Delay interval positions, the washer
pump/motor operation is the same. However, the
FCM also energizes the wiper on/off relay to override
the selected delay interval and operate the wiper
motor in a continuous low speed mode for as long as
the control knob is held depressed, then de-energizes
the relay and reverts to the selected delay mode
interval several wipe cycles after the control knob is
released. If the control knob is held depressed for
more than about thirty seconds, the FCM will sus-
pend washer pump/motor operation until the knob is
released for about two seconds, then cycled back to
the Wash position.
WIPE-AFTER-WASH MODE
When the control knob on the control stalk of the
multi-function switch is depressed to the momentary
Wash position for more than about one-half second
while the wiper system is not operating, the instru-
ment cluster sends an electronic washer switch mes-
sage to the FCM, then the FCM the directs battery
current to the washer pump/motor unit and energizes
the wiper on/off relay. This will cause the washer
pump/motor unit to be energized and operate the
wiper motor in a continuous low speed mode for as
long as the Wash switch is held closed up to about
thirty seconds. When the control knob is released,
the FCM de-energizes the washer pump/motor unit,
but allows the wiper motor to operate for several
additional wipe cycles before it de-energizes the
wiper on/off relay and parks the wiper blades near
the base of the windshield.
If the control knob is held depressed for more than
about thirty seconds, the FCM will suspend washer
pump/motor operation until the knob is released for
about two seconds, then cycled back to the Wash
position; however, the wipers will continue to operate
for as long as the Wash switch is held closed. The
FCM monitors the changing state of the wiper motor
park switch through a hard wired wiper park switch
sense circuit input. This input allows the FCM to
count the number of wipe cycles that occur after the
Wash switch is released, and to determine the proper
DRWIPERS/WASHERS 8R - 5
WIPERS/WASHERS (Continued)

interval at which to de-energize the wiper on/off
relay to complete the wipe-after-wash mode cycle.
DIAGNOSIS AND TESTING - WIPER &
WASHER SYSTEM
If the wiper motor operates, but the wipers do not
move on the windshield, replace the faulty wiper
module. If the washer pump/motor operates, but no
washer fluid is dispensed on the glass; or, if the wip-
ers operate, but chatter, lift, or do not clear the glass,
clean and inspect the wiper and washer system com-
ponents as required. (Refer to 8 - ELECTRICAL/
WIPERS/WASHERS - CLEANING) and (Refer to 8 -
ELECTRICAL/WIPERS/WASHERS - INSPECTION).
For diagnosis and testing of the multi-function
switch (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/MULTI-FUNCTION SWITCH -
DIAGNOSIS AND TESTING). Refer to the appropri-
ate 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.
The hard wired circuits and components of the
wiper and washer system may be diagnosed and
tested using conventional diagnostic tools and proce-
dures. However, conventional diagnostic methods
may not prove conclusive in the diagnosis of the
instrument cluster, the Front Control Module (FCM),
or the electronic message inputs to or outputs from
the instrument cluster and the FCM that control the
various wiper and washer system operating modes.
The most reliable, efficient, and accurate means to
diagnose the instrument cluster, the FCM, or the
electronic message inputs and outputs related to the
various wiper and washer system operating modes
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
CLEANING - WIPER & WASHER SYSTEM
WIPER SYSTEM
The squeegees of wiper blades exposed to the ele-
ments for a long time tend to lose their wiping effec-
tiveness. Periodic cleaning of the squeegees is
suggested to remove any deposits of salt or road film.
The wiper blades, arms, and windshield glass should
only be cleaned using a sponge or soft cloth and
windshield washer fluid, a mild detergent, or a non-
abrasive cleaner. If the wiper blades continue to
leave streaks, smears, hazing, or beading on the
glass after thorough cleaning of the squeegees and
the glass, the entire wiper blade assembly must be
replaced.
CAUTION: Protect the rubber squeegees of the
wiper blades from any petroleum-based cleaners,
solvents, or contaminants. These products can rap-
idly deteriorate the rubber squeegees.
WASHER SYSTEM
If the washer system is contaminated with foreign
material, drain the washer reservoir by removing the
washer pump/motor from the reservoir. Clean foreign
material from the inside of the washer pump/motor
inlet filter screen and the washer reservoir using
clean washer fluid, a mild detergent, or a non-abra-
sive cleaner. Flush foreign material from the washer
system plumbing by first disconnecting the washer
hoses from the washer nozzles, then running the
washer pump/motor to run clean washer fluid or
water through the system. Plugged or restricted
washer nozzles should be carefully back-flushed
using compressed air. If the washer nozzle obstruc-
tion cannot be cleared, replace the washer nozzle.
CAUTION: Never introduce petroleum-based clean-
ers, solvents, or contaminants into the washer sys-
tem. These products can rapidly deteriorate the
rubber seals and hoses of the washer system, as
well as the rubber squeegees of the wiper blades.
CAUTION: Never use compressed air to flush the
washer system plumbing. Compressed air pres-
sures are too great for the washer system plumbing
components and will result in further system dam-
age. Never use sharp instruments to clear a
plugged washer nozzle or damage to the nozzle ori-
fice and improper nozzle spray patterns will result.
8R - 6 WIPERS/WASHERSDR
WIPERS/WASHERS (Continued)