door lock MERCEDES-BENZ SPRINTER 2006 Workshop Manual

10.5 POWER DOOR LOCKS/RKE
10.5.1 FRONT DOORS
S
C
H
E
M
A
T
I
C
D
I
A
G
R
A
M
S
296
SCHEMATIC DIAGRAMS

10.5.3 SWITCH AND MISCELLANEOUS CIRCUITS
S
C
H
E
M
A
T
I
C
D
I
A
G
R
A
M
S
298
SCHEMATIC DIAGRAMS
10.5 POWER DOOR LOCKS/RKE (Continued)

the status of the driver side front seat belt. This
audible warning occurs independent of the visual
warning provided by the EMIC ªSeatbeltº indicator.
²Lights-On Warning- The EMIC chime tone
generator will generate repetitive chime tones at a
fast rate when either front door is opened with the
ignition switch in any position except On, and the
exterior lights are turned On. The EMIC uses inter-
nal programming and hard wired inputs from the left
(lighting) control stalk of the multi-function switch,
the ignition switch, and both front door jamb
switches to determine the current status of these
switches. This chime will continue to sound until the
exterior lighting is turned Off, until the ignition
switch is turned to the On position, or until both
front doors are closed, whichever occurs first.
²Key-In-Ignition Warning- The EMIC chime
tone generator will generate repetitive chime tones at
a fast rate when the key is in the ignition lock cylin-
der, the ignition switch is in any position except On,
and either front door is opened. The EMIC uses
internal programming and hard wired inputs from
the key-in ignition switch, the ignition switch, and
both front door jamb switches to determine the cur-
rent status of these switches. The chime will con-
tinue to sound until the key is removed from the
ignition lock cylinder, until the ignition switch is
turned to the On position, or until both front doors
are closed, whichever occurs first.
²Audible Turn Signal/Hazard Warning Sup-
port- The EMIC contactless relay will generate
repetitive clicks at a slow rate during normal turn
signal/hazard warning operation, or at a fast rate
when a turn signal lamp bulb or circuit is inopera-
tive, in concert with the operation of the turn signal
indicators in the cluster. These clicks are designed to
emulate the sound of the opening and closing of the
contact points in a conventional electromechanical
turn signal or hazard warning flasher. The EMIC
uses a hard wired input received from the turn sig-
nal relay in the fuse block beneath the steering col-
umn through the turn signal or hazard warning
switch circuitry of the multi-function switch to deter-
mine when to flash the turn signal indicators and
activate the contactless relay on the cluster electronic
circuit board. The turn signal clicks will continue to
sound until the turn signal switch is turned Off, or
until the ignition switch is turned to the Off position,
whichever occurs first. The hazard warning clicks
will continue to sound until the hazard warning
switch is turned Off.
The EMIC provides chime service for all available
features in the chime warning system. The EMIC relies
upon its internal programming and hard wired inputs
from the front door ajar switches, the key-in ignition
switch, the ignition switch, the seat belt switch, and the
turn signal/hazard warning (multi-function) switches.
The EMIC relies upon electronic message inputsreceived from other electronic modules over the CAN
data bus network to provide chime service for the low
engine oil level warning. Upon receiving the proper
inputs, the EMIC activates the chime tone generator or
the contactless relay to provide the audible warning to
the vehicle operator. The internal programming of the
EMIC determines the priority of each chime request
input that is received, as well as the rate and duration
of each tone that is to be generated. See the owner's
manual in the vehicle glove box for more information on
the features provided by the chime warning system.
The hard wired chime warning system inputs to
the EMIC, as well as other hard wired circuits for
this system may be diagnosed and tested using con-
ventional diagnostic tools and procedures. However,
conventional diagnostic methods may not prove con-
clusive in the diagnosis of the EMIC, the CAN data
bus network, or the electronic message inputs used
by the EMIC to provide chime warning system ser-
vice. The most reliable, efficient, and accurate means
to diagnose the EMIC, the CAN data bus network,
and the electronic message inputs for the chime
warning system requires the use of a diagnostic scan
tool. Refer to the appropriate diagnostic information.
DIAGNOSIS AND TESTING - CHIME WARNING
SYSTEM
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, or instrument panel component diagno-
sis or service. Disconnect and isolate the battery
negative (ground) cable, then wait two minutes for
the system capacitor to discharge before perform-
ing further diagnosis or service. This is the only
sure way to disable the supplemental restraint sys-
tem. Failure to take the proper precautions could
result in accidental airbag deployment.
The hard wired chime warning system inputs to
the ElectroMechanical Instrument Cluster (EMIC),
as well as other hard wired circuits for this system
may be diagnosed and tested using conventional
diagnostic tools and procedures. However, conven-
tional diagnostic methods may not prove conclusive
in the diagnosis of the EMIC, the Controller Area
Network (CAN) data bus network, or the electronic
message inputs used by the EMIC to provide chime
warning system service. The most reliable, efficient,
and accurate means to diagnose the EMIC, the CAN
data bus network, and the electronic message inputs
for the chime warning system requires the use of a
diagnostic scan tool. Refer to the appropriate diag-
nostic information.
8B - 2 CHIME/BUZZERVA

ELECTRONIC CONTROL MODULES
TABLE OF CONTENTS
page page
CENTRAL TIMER MODULE
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING - CENTRAL TIMER
MODULE.............................2
REMOVAL.............................2
INSTALLATION..........................3
CONTROLLER ANTILOCK BRAKE
DESCRIPTION..........................3
REMOVAL.............................3INSTALLATION..........................3
ENGINE CONTROL MODULE
DESCRIPTION..........................3
REMOVAL.............................6
INSTALLATION..........................6
TRANSMISSION CONTROL MODULE
DESCRIPTION..........................6
OPERATION............................7
STANDARD PROCEDURE - TCM ADAPTATION . 10
CENTRAL TIMER MODULE
DESCRIPTION
The central timer module (CTM) is located beneath
the driver seat. The CTM uses information carried on
the programmable communications interface (PCI)
data bus network along with many hard wired inputs
to monitor many sensor and switch inputs. In
response to those inputs, the circuitry and program-
ming of the CTM allow it to supply the vehicle occu-
pants with audible and visual information, and to
control and integrate many functions and features of
the vehicle through both hard wired outputs and the
transmission of message outputs to other modules in
the vehicle over the PCI data bus.
The features that the CTM supports or controls
include the following:
²Central Locking- The CTM on vehicles
equipped with the optional Vehicle Theft Security
System (VTSS) includes a central locking/unlocking
feature.
²Enhanced Accident Response- The CTM pro-
vides an optional enhanced accident response fea-
ture. This is a programmable feature.
²Panic Mode- The CTM provides support for
the optional RKE system panic mode including horn,
headlamp, and park lamp flash features.
²Power Lock Control- The CTM provides the
optional power lock system features, including sup-
port for the automatic door lock and door lock inhibit
modes.
²Programmable Features- The CTM provides
support for certain programmable features.
²Remote Keyless Entry- The CTM provides
the optional Remote Keyless Entry (RKE) system fea-
tures, including support for the RKE Lock (with
optional horn and park lamps flash), Unlock (with
park lamps flash, driver-door-only unlock, andunlock-all-doors), Panic, and illuminated entry
modes, as well as the ability to be programmed to
recognize up to four RKE transmitters. The RKE
horn, driver-door-only unlock, and unlock-all-doors
features are programmable.
²Vehicle Theft Security System- The CTM
provides control of the optional Vehicle Theft Secu-
rity System (VTSS) features, including support for
the central locking/unlocking mode and control of the
Security indicator in the instrument cluster.
Hard wired circuitry connects the CTM to the elec-
trical system of the vehicle. Refer to the appropriate
wiring information.
Many of the features in the vehicle controlled or
supported by the CTM are programmable using the
DRBIIItscan tool. However, if any of the CTM hard-
ware components are damaged or faulty, the entire
CTM unit must be replaced. The hard wired inputs
or outputs of all CTM versions can be diagnosed
using conventional diagnostic tools and methods;
however, for diagnosis of the CTM or the PCI data
bus, the use of a DRBIIItscan tool is required. Refer
to the appropriate diagnostic information.
OPERATION
The central timer module (CTM) monitors many
hard wired switch and sensor inputs as well as those
resources it shares with other modules in the vehicle
through its communication over the programmable
communications interface (PCI) data bus network.
The internal programming and all of these inputs
allow the CTM to determine the tasks it needs to
perform and their priorities, as well as both the stan-
dard and optional features that it should provide.
The CTM then performs those tasks and provides
those features through both PCI data bus communi-
cation with other modules and hard wired outputs
through a number of driver circuits, relays, and
VAELECTRONIC CONTROL MODULES 8E - 1

actuators.These outputs allow the CTM the ability to
control numerous accessory systems in the vehicle.
The CTM monitors its own internal circuitry as
well as many of its input and output circuits, and
will store a Diagnostic Trouble Code (DTC) in elec-
tronic memory for any failure it detects. These DTCs
can be retrieved and diagnosed using a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
HARD WIRED INPUTS
The hard wired inputs to the CTM include the fol-
lowing:
²Fused B(+)
²Fused ignition switch output (run-acc)
²Fused ignition switch output (run-start)
²Ground
²Key-in ignition switch sense
²Sliding door switch sense
²Passenger door switch sense
²Driver door switch sense
²PCI bus circuit
HARD WIRED OUTPUTS
The hard wired outputs of the CTM include the fol-
lowing:
²Door lock relay output
²Door unlock relay output
²VTSS indicator driver
MESSAGING
The CTM uses the following messages received
from other electronic modules over the PCI data bus:
²Airbag Deploy (ACM)
²Beep request (CMTC)
²Charging System Failure (PCM)
²Chime request (EMIC)
²Engine RPM (PCM)
²OK to Arm VTSS (PCM)
²Security indicator request (SKIM)
²System Voltage (PCM)
²Valid/Invalid Key (SKIM)
²Vehicle Distance (PCM)
²Vehicle Speed (PCM)
DIAGNOSIS AND TESTING - CENTRAL TIMER
MODULE
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, or instrument panel component diagno-
sis or service. Disconnect and isolate the battery
negative (ground) cable, then wait two minutes for
the system capacitor to discharge before perform-
ing further diagnosis or service. This is the only
sure way to disable the supplemental restraint sys-tem. Failure to take the proper precautions could
result in accidental airbag deployment.
The hard wired inputs to and outputs from the
central timer module (CTM) may be diagnosed and
tested using conventional diagnostic tools and meth-
ods. Refer to the appropriate wiring information.
However, conventional diagnostic methods may not
prove conclusive in the diagnosis of the CTM. In
order to obtain conclusive testing of the CTM, the
programmable communications interface (PCI) data
bus network and all of the modules that provide
inputs to or receive outputs from the CTM must also
be checked. The most reliable, efficient, and accurate
means to diagnose the CTM, the PCI data bus net-
work, and the modules that provide inputs to, or
receive outputs from, the CTM requires the use of a
DRBIIItscan tool. Refer to the appropriate diagnos-
tic information.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Slide the driver seat to the full forward posi-
tion.
(3) Disconnect the wire harness connector for the
seat belt latch. (Fig. 1).
(4) Remove the screws that secure the closeout
panel beneathe the driver seat cushion and remove
the panel.
(5) Remove the screws that secure the central
timer module to the bracket.
(6) Disconnect the wire harness connectors from
the central timer module.
(7) Remove the central timer module from the
vehicle.
8E - 2 ELECTRONIC CONTROL MODULESVA

(3) Using a voltmeter connected to the battery
posts (see the instructions provided by the manufac-
turer of the voltmeter), measure the open-circuit volt-
age (Fig. 5).
See the Open-Circuit Voltage Table. This voltage
reading will indicate the battery state-of-charge, but
will not reveal its cranking capacity. If a battery has
an open-circuit voltage reading of 12.4 volts or
greater, it may be load tested to reveal its cranking
capacity (Refer to 8 - ELECTRICAL/BATTERY SYS-
TEM/BATTERY - STANDARD PROCEDURE).
OPEN CIRCUIT VOLTAGE TABLE
Open Circuit Voltage Charge Percentage
11.7 volts or less 0%
12.0 volts 25%
12.2 volts 50%
12.4 volts 75%
12.6 volts or more 100%
STANDARD PROCEDURE - IGNITION - OFF
DRAW TEST
The term Ignition-Off Draw (IOD) identifies a nor-
mal condition where power is being drained from the
battery with the ignition switch in the Off position. A
normal vehicle electrical system will draw from five
to thirty-five milliamperes (0.005 to 0.035 ampere)
with the ignition switch in the Off position, and all
non-ignition controlled circuits in proper working
order. Up to thirty-five milliamperes are needed to
enable the memory functions for the Powertrain Con-
trol Module (PCM), digital clock, electronically tuned
radio, and other modules which may vary with the
vehicle equipment.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 fuseblock. This will reduce battery discharg-
ing.
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.
(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 Fuse Blocks, one at a time until the
amperage reading becomes very low, or nonexistent.
Refer to the appropriate wiring information in this
service manual for complete fuseblock fuse, circuit
breaker, and circuit identification. This will isolate
Fig. 5 Testing Open Circuit Voltage
8F - 10 BATTERY SYSTEMVA

INDICATORS
Indicators are located in various positions within
the EMIC and are all connected to the EMIC elec-
tronic circuit board. The ambient temperature indica-
tor (optional), brake indicator, brake wear indicator,
charging indicator, coolant low indicator, high beam
indicator, low fuel indicator, park brake indicator,
seatbelt indicator, turn signal indicators, and washer
fluid indicator operate based upon hard wired inputs
to the EMIC. The airbag (SRS) indicator is normally
controlled by a hard wired input from the Airbag
Control Module (ACM); however, if the EMIC sees an
abnormal or no input from the ACM, it will automat-
ically turn the airbag indicator On until the hard
wired input from the ACM has been restored. The
Malfunction Indicator Lamp (MIL) is normally con-
trolled by CAN data bus messages from the Engine
Control Module (ECM); however, if the EMIC loses
CAN data bus communication, the EMIC circuitry
will automatically turn the MIL on until CAN data
bus communication is restored. The EMIC uses CAN
data bus messages from the ECM, the ACM, and the
Controller Antilock Brake to control all of the
remaining indicators.
The various EMIC indicators are controlled by dif-
ferent strategies; some receive battery feed from the
EMIC circuitry and have a switched ground, while
others are grounded through the EMIC circuitry and
have a switched battery feed. However, all indicators
are completely controlled by the EMIC microproces-
sor based upon various hard wired and electronic
message inputs. Except for the indications provided
by the multi-function indicator Liquid Crystal Dis-
play (LCD) unit, all indicators are illuminated at a
fixed intensity, which is not affected by the selected
illumination intensity of the EMIC general illumina-
tion lamps.
The hard wired indicator inputs may be diagnosed
using conventional diagnostic methods. However,
proper testing of the EMIC circuitry and the CAN
bus message controlled indicators requires the use of
a diagnostic scan tool. Refer to the appropriate diag-
nostic information. Specific details of the operation
for each indicator may be found elsewhere in this
service information.
CLUSTER ILLUMINATION
The EMIC has several general illumination lamps
that are illuminated when the exterior lighting is
turned on with the multi-function switch. The illumi-
nation intensity of these lamps is adjusted by a dim-
ming level input received from the multi-function
indicator ª+º (plus) and ª±º (minus) switch push but-
tons that extend through the lower edge of the clus-
ter lens below the right end of the multi-function
indicator. When the exterior lighting is turned Off,
the display is illuminated at maximum brightness.
When the exterior lighting is turned On and thetransmission gear selector is in the Park position,
depressing the plus switch push button brightens the
display lighting, and depressing the minus switch
push button dims the display lighting. The EMIC
also provides a Pulse-Width Modulated (PWM) panel
lamps dimmer output that can be used to synchro-
nize the illumination lighting levels of external illu-
mination lamps (up to about 23 to 30 watts) with
that of the EMIC.
The hard wired multi-function switch input and
the EMIC panel lamps dimmer output may be diag-
nosed using conventional diagnostic methods. How-
ever, proper testing of the PWM control of the EMIC
and the electronic dimming level inputs from the
multi-function indicator push buttons requires the
use of a diagnostic scan tool. Refer to the appropriate
diagnostic information.
INPUT AND OUTPUT CIRCUITS
HARD WIRED INPUTS
The hard wired inputs to the EMIC include the fol-
lowing:
NOTE: Final approved circuit names were not yet
available at the time this information was compiled.
²Airbag Indicator Driver
²Ambient Temperature Sensor Signal
(Optional)
²Brake Wear Indicator Sense
²Charging Indicator Driver
²Coolant Level Switch Sense
²Front Door Jamb Switch Sense
²Fuel Level Sensor Signal
²Fused B(+)
²Fused Ignition Switch Output
²High Beam Indicator Driver
²Key-In Ignition Switch Sense
²Left Turn Signal
²Park Brake Switch Sense
²Right Turn Signal
²Seat Belt Switch Sense
²Washer Fluid Switch Sense (Optional)
Refer to the appropriate wiring information for
additional details.
HARD WIRED OUTPUTS
The hard wired outputs of the EMIC include the
following:
²Engine Running Relay Control
²Panel Lamps Driver
Refer to the appropriate wiring information for
additional details.
8J - 6 INSTRUMENT CLUSTERVA

REAR TURN LAMP BULB
REMOVAL.............................23
INSTALLATION.........................23
REPEATER LAMP BULB
REMOVAL.............................23
INSTALLATION.........................24
REPEATER LAMP UNIT
REMOVAL.............................24INSTALLATION.........................25
TAIL LAMP UNIT
REMOVAL.............................25
INSTALLATION.........................26
TURN SIGNAL RELAY
REMOVAL.............................26
INSTALLATION.........................26
LAMPS / LIGHTING - EXTE-
RIOR
DESCRIPTION
The exterior lighting system for this model
includes the following exterior lamps:
²Backup Lamps- The backup (or reverse) lamps
are integral to the tail lamp units mounted to the
back of the quarter panel on each side of the tailgate
at the rear of the vehicle.
²Brake Lamps- The brake (or stop) lamps
include a bulb and reflector that are integral to the
tail lamp units mounted to the back of the quarter
panel on each side of the tailgate opening, and the
Center High Mounted Stop Lamp (CHMSL) that is
centered on the rear edge of the roof panel above the
tailgate opening.
²Daytime Running Lamps- Vehicles manufac-
tured for sale in Canada have a Daytime Running
Lamps (DRL) relay that illuminates the low beam
headlamp bulbs whenever the engine is running.
²Fog Lamps- Fog lamp bulbs and reflectors are
included in both front lamp units of vehicles
equipped with this option.
²Hazard Warning Lamps- The hazard warning
lamps include all of the right and left turn signal and
repeater lamps.
²Headlamps- Separate low beam and high
beam headlamp bulbs are installed in the front lamp
unit on each side of the front grille opening. A head-
lamp leveling actuator motor is also integral to each
front lamp unit.
²Park Lamps- The park lamps include the front
park/side marker lamps and front position lamps
that are integral to the front lamp units mounted on
either side of the front grille opening, as well as the
rear park lamps and rear side marker lamps that are
integral to the tail lamp units mounted to the back of
the quarter panel on each side of the tailgate open-
ing. Included in the park lamps circuit are two rear
license plate lamp units mounted on the left rear
tailgate door. The park lamps may also include
optional clearance lamps, which are located on each
side of a vehicle that is so equipped.
²Turn Signal Lamps- The turn signal lamps
include the front turn lamps that are integral to the
front lamp units, the rear turn lamps that are inte-
gral to the tail lamp units, and a repeater lampmounted to each front fender just above the front
wheel opening.
Other components of the exterior lighting system
for this model include:
²Brake Lamp Switch- A plunger-type brake
lamp switch is located on the steering column sup-
port bracket under the instrument panel and actu-
ated by the brake pedal arm.
²Daytime Running Lamp Relays- Vehicles
manufactured for sale in Canada have two Daytime
Running Lamps (DRL) relays. Dedicated right and
left side relays illuminate the low beam headlamp
bulb installed in each front lamp unit whenever the
engine is running. These relays are located in dedi-
cated vehicle wire harness connectors within the
driver side front seat riser.
²Fog Lamp Relay- Vehicles equipped with the
optional fog lamps have a fog lamp relay located in a
dedicated vehicle wire harness connector within the
driver side front seat riser.
²Fog Lamp Switch- A fog lamp switch is
mounted in the instrument cluster bezel, below the
cluster and outboard of the steering column on vehi-
cles equipped with this option.
²Headlamp Leveling Motor- A headlamp lev-
eling actuator motor is located on the back of each
headlamp housing and adjusts both the low beam
headlamp, high beam headlamp, and fog lamp (if
equipped) reflector frames in unison.
²Headlamp Leveling Switch- A thumbwheel
actuated headlamp leveling switch is mounted in the
instrument cluster bezel, below the cluster and out-
board of the steering column.
²Multi-Function Switch- The multi-function
switch is located on the top of the steering column,
just below the steering wheel. The multi-function
switch is connected directly to the fuse block located
below the steering column through an integral inter-
face connector. Only the left (lighting), right (wiper)
control stalks and the hazard warning switch button
for the multi-function switch are visible, the remain-
der of the switch is concealed beneath the steering
column shrouds. The multi-function switch includes a
left (lighting) control stalk and a right (wiper) control
stalk. The left control stalk is dedicated to providing
almost all of the driver controls for the exterior light-
ing system.
²Trailer Tow Connector- Vehicles equipped
with a factory-approved, field-installed trailer towing
8L - 2 LAMPS/LIGHTING - EXTERIORVA

right rear door is standard equipment on wagon mod-
els. The sliding and rear door jamb switches are not
available for van models.
²Entry/Exit Lamp- An entry/exit lamp to illu-
minate each front and sliding side door step well is
optional equipment on wagon models.
²Time Delay Relay- Vehicles equipped with the
optional remote cargo lamp switches also have a time
delay relay located in the electrical center within the
driver side front seat riser.
Hard wired circuitry connects the interior lighting
system components to the electrical system of the
vehicle. These hard wired circuits are integral to sev-
eral wire harnesses, which are routed throughout the
vehicle and retained by many different methods.
These circuits may be connected to each other, to the
vehicle electrical system and to the interior lighting
system components through the use of a combination
of soldered splices, splice block connectors, and many
different types of wire harness terminal connectors
and insulators. Refer to the appropriate wiring infor-
mation. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
further details on wire harness routing and reten-
tion, as well as pin-out and location views for the
various wire harness connectors, splices and grounds.
OPERATION
The interior lighting systems can be divided into
two general classifications based upon the circuit
that controls their operation: The interior lighting
circuit, or the exterior lighting circuit. The hard
wired circuits and components of the interior lighting
systems may be diagnosed and tested using conven-
tional diagnostic tools and procedures.
INTERIOR LIGHTING CIRCUIT
Depending upon the vehicle model (van or wagon)
and the selected vehicle options the interior lighting
circuit may include dome/cargo lamps located over-
head in the front and rear of the vehicle, a dome/
reading lamp located in the header area above the
windshield between the sun visors, and entry/exit
lamps located in the front and sliding side door step
wells.
WAGON MODELS
In all wagon models, the lamps in the interior
lighting circuit are provided with battery current at
all times by a fuse in the fuse block beneath the
steering column. The front, side, and rear door jamb
switches control a ground path for each of these
lamps, except for the optional reading lamp. If the
lamp has an optional integral switch, that switch has
three separate positions. The first position provides a
ground path independent of the door jamb switches
to turn the lamp On. The second, or center position
allows the door jamb switches to control the lamp.The third position segregates that lamp from the
door jamb switch input, turning the lamp Off. In the
case of the optional dome/reading lamp, the integral
lamp switch has a fourth position which will illumi-
nate only the reading lamp bulb.
VAN MODELS
Unless a van model is equipped with an optional
remote cargo lamp switch, all of the lamps in the
interior lighting circuit operate the same way as the
wagon models except that there are only two door
jamb switches, one for each front door. If the vehicle
is equipped with an optional remote cargo lamp
switch, the lamps in the rear of the vehicle on the
interior lighting circuit are provided with battery
current by the time delay relay. The time delay relay
is a smart relay containing active electronic elements
that comprise an electronic timer logic circuit. When
the remote cargo lamp switches provide the proper
input to the time delay relay, the relay logic responds
by energizing the relay control coil. The energized
relay control coil provides battery current to all of
the lamps on the rear interior lighting circuit and to
the indicator Light-Emitting Diode (LED) units in
the remote cargo switches causing each to illuminate.
If a remote cargo lamp switch remains On for more
than about fifteen minutes, the time delay relay will
then automatically de-energize the rear interior
lighting circuits until the remote cargo lamp switch
is cycled Off and then back On.
EXTERIOR LIGHTING CIRCUIT
The exterior lighting circuit provides battery cur-
rent to the optional ash receiver/cigar lighter lamp
and to the illumination Light-Emitting Diode (LED)
unit within the remote cargo lamp switch in the
instrument panel accessory switch bezel whenever
the exterior lamps are turned On.
SPECIFICATIONS - INTERIOR LIGHTING
VALAMPS/LIGHTING - INTERIOR 8L - 29

CARGO / DOME LAMP UNIT
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Insert the tip of a small flat-bladed screwdriver
into the notch on one edge of the cargo/dome lamp
housing to depress the retainer clip and pull that
edge of the lamp away from its mounting location
(Fig. 3).
(3) Pull the cargo/dome lamp unit from its mount-
ing location far enough to access and disconnect the
vehicle wire harness from the lamp connector recep-
tacle.
(4) Remove the cargo/dome lamp unit from its
mounting location.
INSTALLATION
(1) Position the cargo/dome lamp unit to its
mounting location.
(2) Reconnect the vehicle wire harness connector
to the cargo/dome lamp connector receptacle (Fig. 3).
(3) Position the edge of the cargo/dome lamp hous-
ing opposite from the retainer clip into the mounting
hole.
(4) Push firmly and evenly on the notched edge of
the cargo/dome lamp housing until the retainer clip
latches into place.
(5) Reconnect the battery negative cable.
CARGO LAMP SWITCH
REMOVAL
REMOVAL - INSTRUMENT PANEL
(1) Disconnect and isolate the battery negative
cable.(2) Remove the accessory switch bezel from the
instrument panel. (Refer to 23 - BODY/INSTRU-
MENT PANEL/ACCESSORY SWITCH BEZEL -
REMOVAL).
(3) From the back of the accessory switch bezel,
disconnect the vehicle wire harness connector for the
cargo lamp switch from the receptacle on the back of
the switch (Fig. 4).
(4) From the back of the accessory switch bezel,
depress the two latches on the outside of the switch
body and push the switch out through the front of
the bezel.
REMOVAL - BULKHEAD
(1) Disconnect and isolate the battery negative
cable.
(2) Carefully pry the cargo lamp switch and switch
bezel out of the switch box on the back of the cargo
compartment bulkhead panel.
(3) Pull the cargo lamp switch and bezel away
from the switch box far enough to access and discon-
nect the vehicle wire harness connector for the
switch from the receptacle on the back of the switch.
(4) From the back of the switch bezel, depress the
two latches on the outside of the cargo lamp switch
body and push the switch out through the top of the
switch bezel.
REMOVAL - REAR PILLAR
(1) Disconnect and isolate the battery negative
cable.
(2) Carefully pry the cargo lamp switch and switch
bezel out of the switch mounting hole on the inside of
the rear door opening pillar.
Fig. 3 Cargo/Dome Lamp Unit Remove/Install
1 - LAMP HOUSING
2 - SWITCH BUTTON
3 - NOTCHFig. 4 Cargo Lamp Switch - Accessory Switch Bezel
Mounted Remove/Install
1 - SWITCH (TYPICAL)
2 - ACCESSORY SWITCH BEZEL
3 - BLOCK-OUT PLATE
4 - LATCH (2)
VALAMPS/LIGHTING - INTERIOR 8L - 31