2006 MERCEDES-BENZ SPRINTER buttons

circuit board. The fuel gauge is serviced as a unit
with the instrument cluster.
OPERATION
The fuel gauge gives an indication to the vehicle
operator of the level of fuel in the fuel tank. This
gauge is controlled by the instrument cluster circuit
board based upon cluster programming and a hard
wired input received by the cluster from the fuel
level sensor in the fuel tank. The fuel gauge is an air
core magnetic unit that receives battery current on
the instrument cluster electronic circuit board when
the instrument cluster detects that the ignition
switch is in the On position. The cluster is pro-
grammed to move the gauge needle back to the low
end of the scale after the ignition switch is turned to
the Off position. The instrument cluster circuitry
controls the gauge needle position and provides the
following features:
²Fuel Level Sensor Input (At Ignition On)-
When the cluster detects the ignition switch has been
turned to the On position, the cluster moves the
gauge needle to the proper relative position on the
gauge scale as signaled by the fuel level sensor with-
out any electronic damping.
²Fuel Level Sensor Input (After Ignition On)
- After the ignition switch has been turned to the On
position, the cluster applies an algorithm to the input
from the fuel level sensor to electronically dampen
gauge needle movement against the negative effect
that fuel sloshing within the fuel tank can have on
accurate gauge readings.
²Fuel Level Sensor Input Open- If the fuel
level sensor input to the instrument cluster is an
open circuit, the cluster will move the fuel gauge nee-
dle to the ªEº (Empty) position on the gauge scale,
but the low fuel indicator will not be illuminated.
The fuel level sensor in the fuel tank provides a
hard wired input to the instrument cluster circuitry
through the fuel level sense circuit. The fuel level
sensor is a potentiometer that changes resistance
according to the fuel level. The instrument cluster
applies a fuel tank characteristic curve and fuel tank
reserve valve setting to the fuel level sensor input,
which must be configured when the cluster is initial-
ized. These characteristics determine the algorithm
the cluster uses to display the fuel level data on the
fuel gauge and the control for the low fuel warning
indicator. As the fuel level decreases, the resistance
through the fuel level sensor increases. The fuel level
sensor and the fuel level sense circuit to the instru-
ment cluster can be diagnosed using conventional
diagnostic tools and methods. For proper diagnosis of
the instrument cluster circuitry that controls the fuel
gauge, a diagnostic scan tool is required. Refer to the
appropriate diagnostic information.
GEAR SELECTOR INDICATOR
DESCRIPTION
An electronic automatic transmission gear selector
indicator is standard equipment on all instrument
clusters. The gear selector indicator information is
displayed in the center of the multi-function indicator
Liquid Crystal Display (LCD) located near the lower
edge of the instrument cluster, directly below the
speedometer. The gear selector indicator displays the
following characters as they are selected: ªP,º ªR,º
ªN,º ªD,º ª4,º ª3,º ª2,º and ª1.º Respectively, these
characters represent the currently selected park,
reverse, neutral, drive, fourth gear, third gear, second
gear, and first gear positions of the transmission gear
selector lever on the instrument panel.
The indications of the gear selector indicator are
not visible unless the multi-function indicator LCD is
illuminated and the engine is running. When illumi-
nated, each indication appears as a dark character
silhouetted against an amber field. When the exterior
lighting is turned Off, the display is illuminated at
maximum brightness. When the exterior lighting is
turned On, the display illumination level can be
adjusted in concert with the cluster general illumina-
tion lighting using the ª+º (plus) and ª2º (minus)
multi-function indicator push buttons. The gear
selector indicator is serviced as a unit with the
instrument cluster.
OPERATION
The electronic gear selector indicator gives an indi-
cation to the vehicle operator of the transmission
gear that is currently selected with the automatic
transmission gear selector lever. This indicator is
controlled by the instrument cluster circuit board
based upon cluster programming and electronic mes-
sages received from the Transmission Control Module
(TCM) over the Controller Area Network (CAN) data
bus. The gear selector indicator information is dis-
played by the multi-function indicator Liquid Crystal
Display (LCD) unit on the instrument cluster elec-
tronic circuit board. The multi-function indicator
LCD is completely controlled by the instrument clus-
ter logic circuit, and that logic will only allow the
gear selector indicator information to be displayed
when the instrument cluster detects that the ignition
switch is in the On position. Therefore, the gear
selector indicator will always be off when the ignition
switch is in any position except On.
The TCM continually monitors the transmission
range sensor, then sends the proper gear selector
indicator position messages to the instrument cluster.
For proper diagnosis of the transmission range sen-
sor, the TCM, the CAN data bus, or the electronic
message inputs to the instrument cluster that control
the gear selector indicator, a diagnostic scan tool is
8J - 18 INSTRUMENT CLUSTERVA

next required engine oil maintenance is anticipated.
ASSYST also provides several audible indications
using the electronic tone generator on the instrument
cluster circuit board to supplement these visual dis-
plays.
The indications of the ASSYST engine oil mainte-
nance indicator are not visible when the LCD is not
illuminated. When illuminated, the ASSYST indica-
tions appear as dark characters and icons silhouetted
against an amber field. When the exterior lighting is
turned Off, the display is illuminated at maximum
brightness. When the exterior lighting is turned On,
the display illumination level can be adjusted in con-
cert with the cluster general illumination lighting
using the ª+º (plus) and ª2º (minus) multi-function
indicator push buttons. The ASSYST engine oil main-
tenance indicator is serviced as a unit with the
instrument cluster.
OPERATION
The ASSYST engine oil maintenance indicator
microprocessor uses numerous criteria besides time
and mileage to evaluate vehicle maintenance require-
ments. Time data is taken from the electronic digital
clock integral to the instrument cluster. Vehicle dis-
tance data is obtained from the Controller Antilock
Brake (CAB) over the Controller Area Network
(CAN) data bus. Coolant temperature, engine oil
temperature, engine oil level, engine oil quality,
engine speed, and engine load data are obtained from
the Engine Control Module (ECM) over the CAN
data bus. Using all of the available data and internal
programming, the ASSYST microprocessor then cal-
culates the estimated time and distance to the next
required engine oil maintenance interval. The
ASSYST uses the multi-function indicator LCD to
display that data and, when necessary, issues audible
alerts to the vehicle operator through the electronic
tone generator on the cluster circuit board.
See the owner's manual in the vehicle glove box for
more information on the features, use, operation and
resetting procedures for the ASSYST maintenance
computer. Proper diagnosis and testing of the
ASSYST engine oil maintenance computer, the CAN
data bus and the electronic data bus message inputs
to the EMIC that are used by the ASSYST computer
for its calculations requires the use of a diagnostic
scan tool. Refer to the appropriate diagnostic infor-
mation.
MALFUNCTION INDICATOR
LAMP (MIL)
DESCRIPTION
A Malfunction Indicator Lamp (MIL) is standard
equipment on all instrument clusters. The MIL islocated near the lower edge of the instrument cluster,
to the right of the multi-function indicator display.
The MIL consists of the International Control and
Display Symbol icon for ªEngineº imprinted within a
rectangular cutout in the opaque layer of the instru-
ment cluster overlay. The dark outer layer of the
overlay prevents the indicator from being clearly vis-
ible when it is not illuminated. An amber Light
Emitting Diode (LED) behind the cutout in the
opaque layer of the overlay causes the icon to appear
silhouetted against an amber field through the trans-
lucent outer layer of the overlay when the indicator
is illuminated from behind by the LED, which is sol-
dered onto the instrument cluster electronic circuit
board. The MIL is serviced as a unit with the instru-
ment cluster.
OPERATION
The Malfunction Indicator Lamp (MIL) gives an
indication to the vehicle operator when the Engine
Control Module (ECM) has recorded a Diagnostic
Trouble Code (DTC) for an On-Board Diagnostics II
(OBDII) emissions-related circuit or component mal-
function. The MIL is controlled by a transistor on the
instrument cluster circuit board based upon cluster
programming and electronic messages received by
the cluster from the ECM over the Controller Area
Network (CAN) data bus. The MIL Light Emitting
Diode (LED) is completely controlled by the instru-
ment cluster logic circuit, and that logic will only
allow this indicator to operate when the instrument
cluster detects that the ignition switch is in the On
position. Therefore, the LED will always be off when
the ignition switch is in any position except On. The
LED only illuminates when it is provided a path to
ground by the instrument cluster transistor. The
instrument cluster will turn on the MIL for the fol-
lowing reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the MIL is illuminated as a
bulb test. The indicator will remain illuminated until
the engine is started, or until the ignition switch is
turned to the Off position, whichever occurs first.
²MIL Lamp-On Message- Each time the clus-
ter receives a MIL lamp-on message from the ECM,
the indicator will be illuminated. The indicator will
remain illuminated until the detected fault is
repaired, or until the ignition switch is turned to the
Off position, whichever occurs first. For more infor-
mation on the ECM and the DTC set and reset
parameters, (Refer to 25 - EMISSIONS CONTROL -
OPERATION).
²Communication Error- If the cluster receives
no lamp-on or lamp-off message from the ECM, the
MIL is illuminated by the instrument cluster. The
indicator remains controlled and illuminated by the
cluster until a valid lamp-on or lamp-off message is
received from the ECM.
VAINSTRUMENT CLUSTER 8J - 21

The ECM continually monitors the fuel and emis-
sions system circuits and sensors to decide whether
the system is in good operating condition. The ECM
then sends the proper lamp-on or lamp-off messages
to the instrument cluster. If the instrument cluster
turns on the MIL after the bulb test, it may indicate
that a malfunction has occurred and that the fuel
and emissions systems may require service. For
proper diagnosis of the fuel and emissions systems,
the ECM, the CAN data bus, or the electronic mes-
sage inputs to the instrument cluster that control the
MIL, a diagnostic scan tool is required. Refer to the
appropriate diagnostic information.
MULTI - FUNCTION INDICA-
TOR
DESCRIPTION
A multi-function indicator is standard equipment
on all instrument clusters. The multi-function indica-
tor is located near the lower edge of the instrument
cluster, directly below the speedometer. The multi-
function indicator consists of a Liquid Crystal Dis-
play (LCD) unit and four push button-controlled
switches that are soldered onto the instrument clus-
ter electronic circuit board. The LCD is visible
through a large rectangular cutout in the instrument
cluster overlay, while the four switch push buttons
extend through a black plastic switch bezel located
on the cluster lens directly below the LCD. The four
multi-function indicator push buttons allow the vehi-
cle operator to configure and adjust several of the
display features. The buttons are labeled from left to
right: ªmiº (miles) or ªkmº (kilometers), an icon
depicting an analog clock face (clock), ª2º (minus),
and ª+º (plus).
The multi-function indicator LCD displays both
alpha-numeric characters and numerous icons to pro-
vide information to the vehicle operator. The indica-
tions of the multi-function indicator are not visible
when the LCD is not illuminated. When illuminated
the indications appear as dark characters and icons
silhouetted against an amber field. When the exterior
lighting is turned Off, the display is illuminated at
maximum brightness. When the exterior lighting is
turned On the display illumination level can be
adjusted in concert with the cluster general illumina-
tion lighting using the ª+º (plus) and ª2º (minus)
multi-function indicator push buttons. The multi-
function indicator LCD unit and push button
switches are serviced as a unit with the instrument
cluster.
OPERATION
The multi-function indicator has several display
capabilities including odometer, trip odometer, clock,engine oil level data, gear selector indicator
(PRNDL), certain diagnostic information and, on
vehicles so equipped, an optional Active Service SYS-
Tem (ASSYST) engine oil maintenance indicator and
an optional outside ambient temperature indicator.
The multi-function indicator is completely controlled
by the instrument cluster logic circuit, and that logic
will allow this indication to be viewed whenever the
multi-function indicator Liquid Crystal Display
(LCD) is activated. Therefore, the indicator remains
functional regardless of the ignition switch position.
With the ignition switch in the Off or Accessory posi-
tions and the key removed from the ignition lock cyl-
inder, the display is activated when the park lamps
are turned On or, for about thirty seconds after any
one of the multi-function indicator switch push but-
tons is depressed. Otherwise, the display unit is
active for about thirty seconds after the key is
inserted into the ignition lock cylinder, and inactive
about thirty seconds after the key is removed from
the ignition lock cylinder.
The multi-function indicator ªmiº (miles) or
ªkmº(kilometers) switch push button is used to con-
trol the odometer/trip odometer display modes. The
multi-function indicator clock switch push button is
used to control the clock/outside temperature display
modes. The multi-function indicator ª+º (plus) and
ª2º (minus) switch push buttons are used to adjust
the cluster general illumination dimming level, the
clock, and other cluster settings. See the owner's
manual in the vehicle glove box for more information
on the features, use, operation and setting proce-
dures for the various standard and optional multi-
function indicator displays.
Proper testing of the multi-function indicator LCD
unit, the CAN data bus and the electronic data bus
message inputs to the instrument cluster that control
some of the multi-function indicator functions
requires the use of a diagnostic scan tool. Refer to
the appropriate diagnostic information. Additional
details for the odometer/trip odometer, the clock, the
gear selector indicator, the ambient temperature indi-
cator and the ASSYST warning and reminder func-
tions of the multi-function indicator may be found
elsewhere in this service information.
ODOMETER
DESCRIPTION
An odometer and trip odometer are standard
equipment in all instrument clusters. The odometer
and trip odometer values are displayed on the left
side of the multi-function indicator Liquid Crystal
Display (LCD). The LCD is soldered onto the cluster
electronic circuit board and is visible through a win-
dow with a clear lens located near the lower edge of
8J - 22 INSTRUMENT CLUSTERVA

the instrument cluster, directly below the speedome-
ter. However, the odometer and trip odometer infor-
mation are not displayed simultaneously. The ªmiº
(miles) or ªkmº (kilometers) switch on the instrument
cluster circuit board toggles the display between
odometer and trip odometer modes by depressing the
switch push button that extends through the lower
edge of the cluster lens, directly below the multi-
function indicator LCD.
The odometer and trip odometer information is
stored in the instrument cluster memory. This infor-
mation can be increased when the proper inputs are
provided to the instrument cluster, but the informa-
tion cannot be decreased. The odometer can display
values up to 999,999 kilometers (999,999 miles). The
odometer latches at these values, and will not roll
over to zero. The trip odometer can display values up
to 999.9 kilometers (999.9 miles) before it rolls over
to zero. The odometer display does not have a deci-
mal point and will not show values less than a full
unit (kilometer or mile), while the trip odometer dis-
play does have a decimal point and will show tenths
of a unit (kilometer or mile). The unit of measure
(kilometers or miles) for the odometer and trip odom-
eter display is imprinted on the cluster overlay below
the left end of the LCD. The unit of measure for the
instrument cluster odometer/trip odometer is selected
at the time that it is manufactured, and cannot be
changed.
The indications of the odometer/trip odometer are
not visible when the LCD is not illuminated. When
illuminated the indications appear as dark charac-
ters silhouetted against an amber field. When the
exterior lighting is turned Off, the display is illumi-
nated at maximum brightness. When the exterior
lighting is turned On the display illumination level
can be adjusted in concert with the cluster general
illumination lighting using the plus and minus multi-
function indicator push buttons. The odometer has a
ªRental Carº mode, which will activate the multi-
function indicator LCD and illuminate the odometer
information for about thirty seconds after one of the
multi-function indicator push buttons is momentarily
depressed, or after the key is inserted into the igni-
tion switch lock cylinder with the ignition switch in
the Off position.
The odometer/trip odometer and the miles/kilome-
ters switch, and the miles/kilometers switch push
button are serviced as a unit with the instrument
cluster.
OPERATION
The odometer and trip odometer give an indication
to the vehicle operator of the distance the vehicle has
traveled. This indicator is controlled by the instru-
ment cluster circuitry based upon cluster program-
ming and electronic messages received by the cluster
from the Controller Anti-lock Brake (CAB) over theController Area Network (CAN) data bus. The odom-
eter and trip odometer information is displayed by
the multi-function indicator Liquid Crystal Display
(LCD). The LCD will display the odometer informa-
tion whenever it is activated, and will display the
last previously selected odometer or trip odometer
information when the ignition switch is turned to the
On position. The instrument cluster circuitry controls
the LCD and provides the following features:
²Odometer/Trip Odometer Display Toggling-
Actuating the multi-function indicator ªmiº (miles) or
ªkmº (kilometers) switch push button momentarily
with the LCD illuminated will toggle the display
between the odometer and trip odometer information.
Each time the LCD is illuminated with the ignition
switch in the On or Start positions, the display will
automatically return to the last mode previously
selected (odometer or trip odometer).
²Trip Odometer Reset- When the multi-func-
tion indicator ªmiº (miles) or ªkmº (kilometers) switch
push button is pressed and held for longer than
about two seconds, the trip odometer will be reset to
000.0 kilometers (miles). The LCD must be display-
ing the trip odometer information in order for the
trip odometer information to be reset.
The CAB continually monitors the vehicle speed
pulse information received from the four wheel speed
sensors, then sends the proper distance messages to
the instrument cluster. For proper diagnosis of the
wheel speed sensors, the CAB, the CAN data bus, or
the electronic message inputs to the instrument clus-
ter that control the odometer/trip odometer, a diag-
nostic scan tool is required. Refer to the appropriate
diagnostic information.
PARK BRAKE INDICATOR
DESCRIPTION
A park brake indicator is standard equipment on
all instrument clusters. The park brake indicator is
located near the lower edge of the instrument cluster,
to the left of the multi-function indicator display. The
park brake indicator consists of stencil-like cutout of
the word ªPARKº in the opaque layer of the instru-
ment cluster overlay. The dark outer layer of the
overlay prevents the indicator from being clearly vis-
ible when it is not illuminated. A red Light Emitting
Diode (LED) behind the cutout in the opaque layer of
the overlay causes the ªPARKº text to appear in red
through the translucent outer layer of the overlay
when the indicator is illuminated from behind by the
LED, which is soldered onto the instrument cluster
electronic circuit board. The park brake indicator is
serviced as a unit with the instrument cluster.
VAINSTRUMENT CLUSTER 8J - 23

TRANSPONDER KEY
DESCRIPTION
The Sentry Key Immobilizer System (SKIS) which
communicates with the Sentry Key Remote Entry
Module (SKREEM), uses a transponder chip that is
integral to each key fob (Fig. 6). Ignition keys are
supplied with the vehicle when it is shipped from the
factory. The transponder chip is located within the
Remote Keyless Entry (RKE) fob.
OPERATION
Each Sentry Key has a unique transponder identi-
fication code permanently programmed into it by the
manufacturer. Likewise, the Sentry Key Remote
Entry Module (SKREEM) has a unique ªSecret Key9
code programmed into it by the manufacturer as
well. When a Sentry Key is programmed into the
memory of the SKREEM, the SKREEM stores the
transponder identification code from the Sentry Key,
and the Sentry Key learns the ªSecret Keyº code
from the SKREEM. Once the Sentry Key learns the
ªSecret Keyº code of the SKREEM, it is also perma-
nently programmed into the transponder's memory.
The Sentry Key's transponder is within the range
of the SKREEM's transponder ring when it is
inserted into the ignition lock cylinder. When the
ignition switch is turned to the ON position, the
SKREEM communicates with the Sentry Key via a
radio frequency (RF) signal. The SKREEM deter-
mines if a valid key is present based on the informa-
tion it receives from the Sentry Key. If a valid key is
detected, that fact is communicated to the Engine
Control Module (ECM) via the Controller Area Net-
work (CAN) data bus and the vehicle is allowed to
continue running. If an invalid key is received by theECM or no status at all is communicated, the vehicle
will stall after two (2) seconds of running. The indi-
cator light will be flashing at this point. The Sentry
Key's transponder can not be repaired. If it is faulty
or damaged, it must be replaced.
Common communication problems:
²Two transponder keys too close together.
²Speed Pass too close to transponder key.
Solid indicator that there is a system failure.
²Loss of ECM communication.
²Failed transponder ring circuit.
Fig. 6 TRANSPONDER KEY
1 - TRANSPONDER KEY FOB
2 - RKE BUTTONS
3 - INDICATOR LIGHT
4 - KEY BLADE RELEASE BUTTON
5 - KEY BLADE
VAVEHICLE THEFT SECURITY 8Q - 5