2006 MERCEDES-BENZ SPRINTER ESP

Communication Interface (SCI) data bus line for sup-
plemental restraint system programming or diagno-
sis and testing through the 16-way Data Link
Connector (DLC) located on the dash panel below the
driver side end of the instrument panel. A hard wired
output from the ACM is used for control of the airbag
indicator in the ElectroMechanical Instrument Clus-
ter (EMIC). (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER/AIRBAG INDICATOR -
OPERATION).
The ACM microprocessor continuously monitors all
of the supplemental restraint system electrical cir-
cuits to determine the system readiness. If the ACM
detects a monitored system fault, it sets an appropri-
ate Diagnostic Trouble Code (DTC) and sends an out-
put to the EMIC to turn on the airbag indicator. The
ACM illuminates the indicator for about four seconds
each time the ignition switch is turned to the On
position as a bulb test. If the indicator remains illu-
minated for about ten seconds after the ignition
switch is turned to the On position, the ACM has
detected a non-critical fault that poses no danger to
the vehicle occupants. If the airbag indicator illumi-
nates solid (not flashing) while driving or stays on
longer than ten seconds following the bulb test, the
ACM has detected a critical fault that may cause the
airbags not to deploy when required or to deploy
when not required. An active fault only remains for
the duration of the fault, or in some cases, for the
duration of the current ignition switch cycle, while a
stored fault causes a DTC to be stored in memory by
the ACM.
The ACM receives battery current through a fused
ignition switch output circuit. The ACM receives
ground through a ground circuit and take out of the
vehicle wire harness. This take out has an eyelet ter-
minal connector secured by a nut to a ground stud on
the floor panel directly below the ACM within the
driver side seat riser. A case ground is also provided
for the ACM through a ground circuit and eyelet ter-
minal connector secured under the left rear ACM
mounting screw. These connections allow the ACM to
be operational whenever the ignition switch is in the
On position.
The ACM also contains an energy-storage capaci-
tor. When the ignition switch is in the On position,
this capacitor is continually being charged with
enough electrical energy to deploy the supplemental
restraint components for up to one second following a
battery disconnect or failure. The purpose of the
capacitor is to provide backup supplemental restraint
system protection in case there is a loss of battery
current supply to the ACM during an impact.
Two sensors are contained within the ACM, an
electronic impact sensor and a safing sensor. These
electronic sensors are accelerometers that sense the
rate of vehicle deceleration, which provide verifica-
tion of the direction and severity of an impact. Onmodels equipped with optional side curtain airbags,
the ACM also monitors inputs from two remote side
impact sensors located within the left and right front
door step wells to control deployment of the side cur-
tain airbag units.
The safing sensor is an electronic accelerometer
sensor within the ACM that provides an additional
logic input to the ACM microprocessor. The safing
sensor is used to verify the need for a supplemental
restraint deployment by detecting impact energy of a
lesser magnitude than that of the primary electronic
impact sensors, and must exceed a safing threshold
in order for the airbags to deploy. Vehicles equipped
with optional side curtain airbags feature a second
safing sensor within the ACM to provide confirma-
tion to the ACM microprocessor of side impact forces.
This second safing sensor is a bi-directional unit that
detects impact forces from either side of the vehicle.
Pre-programmed decision algorithms in the ACM
microprocessor determine when the deceleration rate
as signaled by the impact sensors and the safing sen-
sors indicate an impact that is severe enough to
require supplemental restraint system protection.
When the programmed conditions are met, the ACM
sends the proper electrical signals to deploy the front
airbags and seat belt tensioners and, if the vehicle is
so equipped, either side curtain airbag unit.
The ACM also provides a hard wired electrical
crash signal output following a supplemental
restraint deployment event. This output is used to
signal other electronic modules in the vehicle to pro-
vide their enhanced accident response features,
which include automatically disabling the engine
from running and unlocking all of the doors. How-
ever, these responses are each dependent upon the
circuits, components, and modules controlling these
features remaining intact from collateral damage
incurred during the vehicle impact.
A single ACM is used for all variations of the sup-
plemental restraint system available in this vehicle.
This ACM is programmable and in order to function
properly it must be programmed for the correct vehi-
cle supplemental restraint system equipment using
an initialization procedure. The initialization proce-
dure requires the use of a diagnostic scan tool. Refer
to the appropriate diagnostic information. The hard
wired inputs and outputs for the ACM may be diag-
nosed and tested using conventional diagnostic tools
and procedures. However, conventional diagnostic
methods will not prove conclusive in the diagnosis of
the ACM or the supplemental restraint system. The
most reliable, efficient, and accurate means to diag-
nose the ACM or the supplemental restraint system
requires the use of a diagnostic scan tool. Refer to
the appropriate diagnostic information.
VARESTRAINTS 8O - 9

(3) Pull the driver airbag away from the steering
wheel far enough to access the electrical connection
at the back of the airbag housing.
CAUTION: Do not pull on the clockspring pigtail
wires to disengage the connector from the driver
airbag inflator connector receptacle. Improper
removal of these pigtail wires and their connector
insulator can result in damage to the airbag circuits
or the connector insulator.
(4) The clockspring driver airbag pigtail wire con-
nector is a tight snap-fit into the airbag inflator con-
nector receptacle, which is located on the back of the
driver airbag housing. Firmly grasp and pull or gen-
tly pry on the connector insulator and pull the con-
nector straight out from the airbag inflator to
disconnect it from the connector receptacle.
(5) Remove the driver airbag from the steering
wheel.
(6) If the driver airbag has been deployed, the
clockspring and the steering wheel must also be
replaced. (Refer to 8 - ELECTRICAL/RESTRAINTS/
CLOCKSPRING - REMOVAL) and (Refer to 19 -
STEERING/COLUMN/STEERING WHEEL -
REMOVAL).
INSTALLATION
The following procedure is for replacement of a
faulty or damaged driver airbag. If the airbag is
faulty or damaged, but not deployed, review the rec-
ommended procedures for handling non-deployed
supplemental restraints. (Refer to 8 - ELECTRICAL/
RESTRAINTS - STANDARD PROCEDURE - HAN-
DLING NON-DEPLOYED SUPPLEMENTAL
RESTRAINTS). If the driver airbag has been
deployed, review the recommended procedures for
service after a supplemental restraint deploymentbefore removing the airbag from the vehicle. (Refer to
8 - ELECTRICAL/RESTRAINTS - STANDARD PRO-
CEDURE - SERVICE AFTER A SUPPLEMENTAL
RESTRAINT DEPLOYMENT).
WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, seat belt
tensioner, impact sensor, or instrument panel com-
ponent diagnosis or service. Disconnect and isolate
the battery negative (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 disable the supplemental
restraint system. Failure to take the proper precau-
tions could result in accidental airbag deployment.
WARNING: To avoid personal injury or death, use
extreme care to prevent any foreign material from
entering the driver airbag, or becoming entrapped
between the driver airbag cushion and the driver
airbag trim cover. Failure to observe this warning
could result in occupant injuries upon airbag
deployment.
WARNING: To avoid personal injury or death, the
driver airbag trim cover must never be painted.
Replacement airbags are serviced with trim covers
in the original colors. Paint may change the way in
which the material of the trim cover responds to an
airbag deployment. Failure to observe this warning
could result in occupant injuries upon airbag
deployment.
Fig. 21 Driver Airbag Remove/Install
1 - AIRBAG CONNECTOR
2 - DRIVER AIRBAG3 - SCREW (2)
4 - STEERING WHEEL
VARESTRAINTS 8O - 19

straight out from the inflator to disconnect it from
the receptacle.
(7) Remove the passenger airbag and airbag door
from the instrument panel as a unit.
INSTALLATION
The following procedure is for replacement of a
faulty or damaged passenger airbag. If the airbag is
faulty or damaged, but not deployed, review the rec-
ommended procedures for handling non-deployed
supplemental restraints. (Refer to 8 - ELECTRICAL/
RESTRAINTS - STANDARD PROCEDURE - HAN-
DLING NON-DEPLOYED SUPPLEMENTAL
RESTRAINTS). If the passenger airbag has been
deployed, review the recommended procedures for
service after a supplemental restraint deployment
before removing the airbag from the vehicle. (Refer to
8 - ELECTRICAL/RESTRAINTS - STANDARD PRO-
CEDURE - SERVICE AFTER A SUPPLEMENTAL
RESTRAINT DEPLOYMENT).
WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, seat belt
tensioner, impact sensor, or instrument panel com-
ponent diagnosis or service. Disconnect and isolate
the battery negative (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 disable the supplemental
restraint system. Failure to take the proper precau-
tions could result in accidental airbag deployment.
WARNING: To avoid personal injury or death, use
extreme care to prevent any foreign material from
entering the passenger airbag, or becoming
entrapped between the passenger airbag cushion
and the passenger airbag door. Failure to observe
this warning could result in occupant injuries upon
airbag deployment.
WARNING: To avoid personal injury or death, the
passenger airbag door must never be painted.
Replacement passenger airbags are serviced with
doors in the original colors. Paint may change the
way in which the material of the airbag door
responds to an airbag deployment. Failure to
observe this warning could result in occupant inju-
ries upon airbag deployment.
(1) Carefully position the passenger airbag and
airbag door unit to the instrument panel (Fig. 29).
(2) When installing the passenger airbag, recon-
nect the vehicle wire harness connector to the airbag
inflator connector receptacle by pressing straight in
on the connector. You can be certain that the connec-tor is fully engaged by listening carefully for a dis-
tinct, audible click as the connector snaps into place.
(3) Push the passenger airbag unit forward far
enough to engage the lower edge of the airbag door
with the two lower clips in the instrument panel.
(4) Install and tighten the two screws that secure
the flange of the passenger airbag housing to the
bracket on the instrument panel structural support.
Tighten the screws to 10 N´m (89 in. lbs.).
(5) Install and tighten the two screws that secure
the passenger airbag door upper clips to the instru-
ment panel base trim. Tighten the screws to 2 N´m
(18 in. lbs.).
(6) Reinstall the instrument panel top cover tray
onto the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/INSTRUMENT PANEL TOP
COVER - TRAY - INSTALLATION).
(7) Do not reconnect the battery negative cable at
this time. The supplemental restraint system verifi-
cation test procedure should be performed following
service of any supplemental restraint system compo-
nent. (Refer to 8 - ELECTRICAL/RESTRAINTS -
STANDARD PROCEDURE - VERIFICATION TEST).
PASSENGER AIRBAG
BRACKET
REMOVAL
WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, seat belt
tensioner, impact sensor, or instrument panel com-
ponent diagnosis or service. Disconnect and isolate
the battery negative (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 disable the supplemental
restraint system. Failure to take the proper precau-
tions could result in accidental airbag deployment.
(1) Remove the passenger airbag from the instru-
ment panel. (Refer to 8 - ELECTRICAL/RE-
STRAINTS/PASSENGER AIRBAG - REMOVAL).
(2) Remove the four screws that secure the passen-
ger airbag bracket to the instrument panel structural
support (Fig. 30).
VARESTRAINTS 8O - 27

other minor debris from the outside windshield glass
surface that might be encountered while driving the
vehicle under numerous types of inclement operating
conditions.
Two wiper systems are available: the standard
intermittent wipe system, or an optional automatic
wipe system. The vehicle operator initiates all wiper
and washer system functions with the multi-function
switch wiper control stalk that extends from the
right side of the steering column, just below the
steering wheel. Depressing, raising, or pulling the
right control stalk of the multi-function switch
selects the desired wiper system operating mode (Fig.
2). The wiper system allows the vehicle operator to
select from two continuous wiper speeds, Hi or Lo,
either a fixed interval intermittent wipe mode or an
auto wipe mode (as the vehicle is equipped), and a
pulse wipe mode. Pushing the knob on the end of the
control stalk towards the steering column activates
the washer pump/motor, which dispenses washer
fluid onto the windshield glass through the washer
nozzles.
The hard wired inputs to and outputs from the
wiper and washer system components may be diag-
nosed and tested using conventional diagnostic tools
and methods. Refer to the appropriate diagnostic
information. Refer to the owner's manual in the vehi-
cle glove box for more information on the features
and operation of the wiper and washer system.
INTERMITTENT WIPE SYSTEM
When the ignition switch is in the On position, bat-
tery current from a fuse in the fuse block underneath
the steering column is provided through a fused igni-
tion switch output (run-start) circuit to the intermit-tent wipe logic circuitry of the wiper, turn signals
and engine start control module within the fuse
block, the multi-function switch, the wiper relay and
the wiper motor park switch. The internal circuitry
of the multi-function switch provides a direct hard
wired battery current output to the low speed or high
speed brushes of the wiper motor when the Low,
High, or Pulse position is selected, which causes the
wipers to cycle at the selected speed for as long as
that switch position remains selected.
In order to provide the intermittent wipe and wipe-
after-wash features, the intermittent wipe logic cir-
cuitry of the wiper, turn signals and engine start
control module within the fuse block monitors inputs
from the intermittent wipe and washer switch cir-
cuitry of the multi-function switch and the park
switch in the wiper motor. When the intermittent
wipe position is selected with the multi-function
switch control stalk, the intermittent wipe logic cir-
cuitry responds by energizing the wiper relay and
calculating the correct delay interval. The energized
wiper relay directs battery current through the inter-
mittent wipe position circuitry of the multi-function
switch to the low speed brush of the wiper motor.
The intermittent wipe logic circuit monitors the
wiper motor operation through the wiper on/off relay
output circuit, which allows it to determine the
proper timing to begin the next wiper blade sweep.
The normal delay interval is about five seconds.
When the Off position of the multi-function switch
wiper control stalk is selected, one of two events is
possible. The event that will occur depends upon the
position of the wiper blades on the windshield at the
moment that the 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, the intermittent wipe logic circuit de-ener-
gizes the wiper 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 closed to battery current
through the fused ignition switch output (run-start)
circuit. The intermittent wipe logic circuit energizes
the wiper relay and the wiper on-off relay output cir-
cuit directs battery current to the low speed brush of
the wiper motor through the normally open contact
of the wiper relay, then through the internal Off posi-
tion circuitry of the multi-function switch. This
causes the wiper motor to continue running until the
wiper blades are in the down position on the wind-
shield and the park switch is again closed to ground.
When the Wash position of the control knob on the
right control stalk of the multi-function switch is
selected, the washer switch circuitry directs battery
current to the washer pump motor and to the inter-
mittent wipe logic circuitry. When the washer switch
Fig. 2 Windshield Wiper/Washer Switch
1 - INTERMITTENT WIPE MODE (OR AUTO WIPE MODE IF
EQUIPPED)
2 - CONTINUOUS LOW SPEED WIPE MODE
3 - CONTINUOUS HIGH SPEED WIPE MODE
4 - WASHER MODE
5 - PULSE WIPE MODE
8R - 4 WIPERS/WASHERSVA

is closed with the wiper system turned Off, the inter-
mittent wipe logic circuitry operates the wiper motor
in the same manner as it does to provide the inter-
mittent wipe mode operation. After the state of the
washer switch changes to open, the intermittent wipe
logic circuitry monitors the wiper motor through the
wiper on-off relay output circuit, which allows it to
monitor the number of wiper blade sweeps. After the
appropriate number of wiper sweeps the intermittent
wipe logic circuitry operates the wiper motor to
return the wipers to their park position, then de-en-
ergizes the wiper relay.
AUTOMATIC WIPE SYSTEM
When the ignition switch is in the On position, bat-
tery current from a fuse in the fuse block underneath
the steering column is provided through a fused igni-
tion switch output (run-start) circuit to the rain sen-
sor control module under the instrument panel, to
the rain sensor within the base of the inside rear
view mirror on the windshield, and to the multi-func-
tion switch. The internal circuitry of the multi-func-
tion switch provides direct hard wired battery
current outputs to the rain sensor control module to
indicate the selected wiper operating mode. The con-
trol module logic monitors the inputs from the multi-
function switch as well as from the rain sensor and
the wiper motor park switch in order to provide the
outputs necessary to operate the wiper motor and the
washer pump motor as requested.
When the automatic wipe position is selected with
the multi-function switch control stalk, the rain sen-
sor control module logic circuitry responds by provid-
ing an acknowledgment sweep of the wipers. The
rain sensor calculates the correct wiper speed and
wiper sweep intervals required to remove the mois-
ture detected on the windshield glass and provides
this input to the rain sensor control module. The con-
trol module then energizes and de-energizes the
wiper motor automatically. The automatic wipe logic
will also provide a wipe-after-wash feature to clear
washer fluid that is directed onto the windshield
when the washer system is utilized.
When the Off position of the multi-function switch
wiper control stalk is selected, one of two events is
possible. The event that will occur depends upon the
position of the wiper blades on the windshield at the
moment that the 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 the rain sensor control module logic cir-
cuit de-energizes the wiper motor. If the wiper blades
are not in the down position at the moment the Off
position is selected, the park switch is an open cir-
cuit. The control module logic circuit directs battery
current to the low speed brush of the wiper motor,
which causes the wiper motor to continue runninguntil the wiper blades are in the down position on
the windshield and the park switch is again closed to
ground.
When the Wash position of the control knob on the
right control stalk of the multi-function switch is
selected with the wiper system turned Off, the rain
sensor control module logic circuitry operates the
wiper motor in the same manner as it does to provide
the automatic wipe mode operation. After the state of
the washer switch changes to open the control mod-
ule monitors the wiper motor through the wiper park
switch sense circuit, which allows it to monitor the
number of wiper blade sweeps. After the appropriate
number of wiper sweeps the control module operates
the wiper motor to return the wipers to their park
position, then de-energizes the wiper motor.
OPERATING MODES
The components of the wiper and washer system
are designed to provide the following operating
modes:
²Automatic Wipe Mode- On vehicles so
equipped, the internal circuitry of the multi-function
switch, the rain sensor control module and the rain
sensor work in concert to provide wiper system oper-
ation automatically whenever moisture is detected on
the windshield glass.
²Continuous Wipe Mode- The two-speed wiper
motor, the internal circuitry of the multi-function
switch, and the wiper system logic circuits work in
concert to provide two continuous wipe cycles, low
speed or high speed.
²Intermittent Wipe Mode- On vehicles so
equipped, the internal circuitry of the multi-function
switch, the intermittent wipe circuitry of the wiper,
turn signals and engine start control module in the
fuse block, and the wiper relay work in concert to
provide an intermittent wipe mode with a single,
fixed delay interval.
²Pulse Wipe Mode- The internal circuitry of
the multi-function switch and the wiper system logic
circuits work in concert to provide a pulse wipe mode
that will allow the wiper motor to be operated for a
single, complete wipe cycle.
²Washer Mode- When the washer system is
activated with the multi-function switch while the
wiper system is operating, washer fluid will be dis-
pensed onto the windshield glass through the washer
nozzles for as long as the washer pump/motor is
energized.
²Wipe-After-Wash Mode- The wiper system
logic circuitry provides a wipe-after-wash feature. If
the wipers are turned Off, this feature will operate
the washer pump/motor and the wipers for as long as
the washer system is activated, then provide several
additional wipe cycles after the washer system is
deactivated before parking the wiper blades near the
base of the windshield.
VAWIPERS/WASHERS 8R - 5

falls below the predetermined minimum, the switch
contacts of the normally open switch close. The
washer fluid level switch is connected to the vehicle
electrical system through the washer pump/motor
unit take out and connector of the vehicle wire har-
ness. The switch receives a path to ground at all
times through another take out of the vehicle wire
harness with a single eyelet terminal connector that
is secured under a ground screw located near the
right headlamp in the engine compartment.
The switch is connected in series between ground
and the washer fluid switch sense input to the Elec-
troMechanical Instrument Cluster (EMIC). When the
switch closes, the EMIC senses the ground on the
washer fluid switch sense circuit. The EMIC is pro-
grammed to respond to this input by illuminating the
washer fluid indicator. The washer fluid level switch
input to the EMIC may be diagnosed using conven-
tional diagnostic tools and methods.
VAWIPERS/WASHERS 8R - 17

TERMINOLOGY
This is a list of terms and definitions used in the
wiring diagrams.
LHD.................Left Hand Drive Vehicles
RHD ...............Right Hand Drive Vehicles
ATX . . Automatic Transmissions-Front Wheel Drive
MTX . . . Manual Transmissions-Front Wheel Drive
AT....Automatic Transmissions-Rear Wheel Drive
MT .....Manual Transmissions-Rear Wheel Drive
SOHC...........Single Over Head Cam Engine
DOHC..........Double Over Head Cam Engine
Built-Up-Export....... Vehicles Built For Sale In
Markets Other Than North America
Except Built-Up-Export . Vehicles Built For Sale In
North America
CIRCUIT INFORMATION
Each wire shown in the diagrams contains a code
which identifies gage of wire, and color.
WIRE COLOR CODE CHART
COLOR CODE COLOR
BL BLUE
BK BLACK
BR BROWN
DB DARK BLUE
DG DARK GREEN
GY GRAY
LB LIGHT BLUE
LG LIGHT GREEN
OR ORANGE
PK PINK
RD RED
TN TAN
VT VIOLET
WT WHITE
YL YELLOW
* WITH TRACER
SECTION IDENTIFICATION AND INFORMATION
The wiring diagrams are grouped into individual
sections. If a component is most likely found in a par-
ticular group, it will be shown complete (all wires,
connectors, and pins) within that group. For exam-
ple, the Auto Shutdown Relay is most likely to be
found in Group 30, so it is shown there complete. It
can, however, be shown partially in another group if
it contains some associated wiring.
Splice diagrams in Section 8W-70 show the entire
splice and provide references to other sections thesplices serves. Section 8W-70 only contains splice dia-
grams that are not shown in their entirety some-
where else in the wiring diagrams.
Section 8W-80 shows each connector and the cir-
cuits involved with that connector. The connectors
are identified using the name/number on the dia-
gram pages.
WIRING SECTION CHART
GROUP TOPIC
8W-01 thru 8W-
09General information and Diagram
Overview
8W-10 thru 8W-
19Main Sources of Power and Ve-
hicle Grounding
8W-20 thru 8W-
29Starting and Charging
8W-30 thru 8W-
39Powertrain/Drivetrain Systems
8W-40 thru 8W-
49Body Electrical items and A/C
8W-50 thru 8W-
59Exterior Lighting, Wipers and
Trailer Tow
8W-60 thru 8W-
69Power Accessories
8W-70 Splice Information
8W-80 Connector Pin Outs
8W-91 Connector, Ground and Splice
Locations
CONNECTOR, GROUND, AND SPLICE INFOR-
MATION
CAUTION: Not all connectors are serviced. Some
connectors are serviced only with a harness. A typ-
ical example might be the Supplemental Restraint
System connectors. Always check parts availability
before attempting a repair.
IDENTIFICATION
In-line connectors are identified by a number, as
follows:
²In-line connectors located in the engine compart-
ment are C100 series numbers
²In-line connectors located in the Instrument
Panel area are C200 series numbers.
²In-line connectors located in the body are C300
series numbers.
²Jumper harness connectors are C400 series
numbers.
VA8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 5

²Grounds and ground connectors are identified
with a ªGº and follow the same series numbering as
the in-line connectors.
²Splices are identified with an ªSº and follow the
same series numbering as the in-line connectors.
²Component connectors are identified by the com-
ponent name instead of a number. Multiple connec-
tors on a component use a C1, C2, etc. identifier.
LOCATIONS
Section 8W-91 contains connector/ground/splice
location illustrations. The illustrations contain the
connector name (or number)/ground number/splice
number and component identification. Connector/
ground/splice location charts in section 8W-91 refer-
ence the figure numbers of the illustrations.
The abbreviation T/O is used in the component
location section to indicate a point in which the wir-
ing harness branches out to a component. The abbre-
viation N/S means Not Shown in the illustrations
WARNINGS - GENERAL
WARNINGSprovide information to prevent per-
sonal injury and vehicle damage. Below is a list of
general warnings that should be followed any time a
vehicle is being serviced.
WARNING: ALWAYS WEAR SAFETY GLASSES FOR
EYE PROTECTION.
WARNING: USE SAFETY STANDS ANYTIME A PRO-
CEDURE REQUIRES BEING UNDER A VEHICLE.
WARNING: BE SURE THAT THE IGNITION SWITCH
ALWAYS IS IN THE OFF POSITION, UNLESS THE
PROCEDURE REQUIRES IT TO BE ON.
WARNING: SET THE PARKING BRAKE WHEN
WORKING ON ANY VEHICLE. AN AUTOMATIC
TRANSMISSION SHOULD BE IN PARK. A MANUAL
TRANSMISSION SHOULD BE IN NEUTRAL.
WARNING: OPERATE THE ENGINE ONLY IN A
WELL-VENTILATED AREA.
WARNING: KEEP AWAY FROM MOVING PARTS
WHEN THE ENGINE IS RUNNING, ESPECIALLY THE
FAN AND BELTS.
WARNING: TO PREVENT SERIOUS BURNS, AVOID
CONTACT WITH HOT PARTS SUCH AS THE RADIA-TOR, EXHAUST MANIFOLD(S), TAIL PIPE, CATA-
LYTIC CONVERTER AND MUFFLER.
WARNING: DO NOT ALLOW FLAME OR SPARKS
NEAR THE BATTERY. GASES ARE ALWAYS
PRESENT IN AND AROUND THE BATTERY.
WARNING: ALWAYS REMOVE RINGS, WATCHES,
LOOSE HANGING JEWELRY AND AVOID LOOSE
CLOTHING.
DIAGNOSIS AND TESTING
WIRING HARNESS
TROUBLESHOOTING TOOLS
When diagnosing a problem in an electrical circuit
there are several common tools necessary. These tools
are listed and explained below.
²Jumper Wire - This is a test wire used to con-
nect two points of a circuit. It can be used to bypass
an open in a circuit.
WARNING: NEVER USE A JUMPER WIRE ACROSS
A LOAD, SUCH AS A MOTOR, CONNECTED
BETWEEN A BATTERY FEED AND GROUND.
²Voltmeter - Used to check for voltage on a cir-
cuit. Always connect the black lead to a known good
ground and the red lead to the positive side of the
circuit.
CAUTION: Most of the electrical components used
in today's vehicles are Solid State. When checking
voltages in these circuits, use a meter with a 10 -
megohm or greater impedance rating.
²Ohmmeter - Used to check the resistance
between two points of a circuit. Low or no resistance
in a circuit means good continuity.
CAUTION: Most of the electrical components used
in today's vehicles are Solid State. When checking
resistance in these circuits use a meter with a 10 -
megohm or greater impedance rating. In addition,
make sure the power is disconnected from the cir-
cuit. Circuits that are powered up by the vehicle's
electrical system can cause damage to the equip-
ment and provide false readings.
²Probing Tools - These tools are used for probing
terminals in connectors (Fig. 4). Select the proper
size tool from Special Tool Package 6807, and insert
it into the terminal being tested. Use the other end
of the tool to insert the meter probe.
8W - 01 - 6 8W-01 WIRING DIAGRAM INFORMATIONVA