Mercedes-Benz Sprinter / Dodge Sprinter. Manual — part 221

Located between the rear cover and the cluster

hood is the cluster housing. The molded plastic clus-
ter housing serves as the carrier for the cluster elec-
tronic

circuit

board

and

circuitry,

the

cluster

connector receptacles, the gauges, a Light Emitting
Diode (LED) for each cluster indicator and general
illumination lamp, the multi-function indicator LCD
unit, electronic tone generators, the cluster overlay,
the gauge pointers, the multi-function indicator
switches and the four switch push buttons.

The cluster overlay is a laminated plastic unit. The

dark, visible, outer surface of the overlay is marked
with all of the gauge dial faces and graduations, but
this layer is also translucent. The darkness of this
outer layer prevents the cluster from appearing clut-
tered or busy by concealing the cluster indicators
that are not illuminated, while the translucence of
this layer allows those indicators and icons that are
illuminated to be readily visible. The underlying
layer of the overlay is opaque and allows light from
the LED for each of the various indicators and illu-
mination lamps behind it to be visible through the
outer layer of the overlay only through predeter-
mined cutouts. A rectangular opening in the overlay
at the base of the speedometer provides a window
through which the illuminated multi-function indica-
tor LCD unit can be viewed.

Several versions of the EMIC module are offered

on this model. These versions accommodate all of the
variations of optional equipment and regulatory
requirements for the various markets in which the
vehicle will be offered. The microprocessor-based
EMIC utilizes integrated circuitry, Electrically Eras-
able Programmable Read Only Memory (EEPROM)
type memory storage, information carried on the
Controller Area Network (CAN) data bus, along with
several hard wired analog and multiplexed inputs to
monitor systems, sensors and switches throughout
the vehicle.

In response to those inputs, the hardware and soft-

ware of the EMIC allow it to control and integrate
many electronic functions and features of the vehicle
through both hard wired outputs and the transmis-
sion of electronic message outputs to other electronic
modules in the vehicle over the CAN data bus. (Refer
to

8

-

ELECTRICAL/ELECTRONIC

CONTROL

MODULES/COMMUNICATION - DESCRIPTION -
CAN BUS).

Besides typical instrument cluster gauge and indi-

cator support, the electronic functions and features
that the EMIC supports or controls include the fol-
lowing:

• Active Service System - In vehicles equipped

with the Active Service SYSTem (ASSYST) engine oil
maintenance indicator option, the EMIC electronic
circuit board includes a second dedicated micropro-
cessor. This second microprocessor evaluates various
data including time, mileage, and driving conditions

to calculate the required engine oil service intervals,
and provides both visual and audible alerts to the
vehicle operator when certain engine oil maintenance
services are required.

• Audible Warnings - The EMIC electronic cir-

cuit board is equipped with an audible tone generator
and programming that allows it to provide various
audible alerts to the vehicle operator, including buzz-
ing and chime tones. An audible contactless elec-
tronic relay is also soldered onto the circuit board to
produce audible clicks that is synchronized with turn
signal indicator flashing to emulate the sounds of a
conventional turn signal or hazard warning flasher.
These audible clicks can occur at one of two rates to
emulate both normal and bulb-out turn or hazard
flasher

operation.

(Refer

to

8

-

ELECTRICAL/

CHIME/BUZZER - DESCRIPTION).

• Panel Lamps Dimming Control - The EMIC

provides a hard wired 12-volt Pulse-Width Modulated
(PWM) output that synchronizes the dimming level
of all panel lamps dimmer controlled lamps with that
of the cluster general illumination lamps and multi-
function indicator.

The EMIC houses four analog gauges and has pro-

visions for up to nineteen indicators (Fig. 3). The
EMIC includes the following analog gauges:

• Coolant Temperature Gauge

• Fuel Gauge

• Speedometer

• Tachometer
The EMIC includes provisions for the following

indicators (Fig. 3):

• Airbag (SRS) Indicator

• Antilock Brake System (ABS) Indicator

• Brake Indicator

• Brake Wear Indicator

• Charging Indicator

• Clogged Fuel Filter Indicator

• Constant Engine Speed (ADR) Indicator

• Coolant Low Indicator

• Electronic Stability Program (ESP) Indica-

tor

• High Beam Indicator

• Low Fuel Indicator

• Malfunction Indicator Lamp (MIL)

• Multi-Function Indicator (LCD)

• Park Brake Indicator

• Seatbelt Indicator

• Traction Control (ASR) Indicator

• Traction Control (ASR) Malfunction Indica-

tor

• Turn Signal (Right and Left) Indicators

• Washer Fluid Indicator

• Wait-To-Start Indicator

• Water-In-Fuel Indicator

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INSTRUMENT CLUSTER

8J - 3

Except for the indications provided within the

multi-function indicator LCD unit, each indicator in
the EMIC is illuminated by a dedicated LED that is
soldered onto the EMIC electronic circuit board.
Cluster illumination is accomplished by dimmable
LED back lighting, which illuminates the gauges for
visibility when the exterior lighting is turned on. The
cluster general illumination LED units are also sol-
dered onto the EMIC electronic circuit board. The
LED units are not available for service replacement
and, if damaged or faulty, the entire EMIC must be
replaced.

Hard wired circuitry connects the EMIC to the

electrical system of the vehicle. These hard wired cir-
cuits are integral to the vehicle 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 sys-
tem and to the EMIC through the use of a combina-
tion of soldered splices, splice block connectors, and
many different types of wire harness terminal con-
nectors and insulators. Refer to the appropriate wir-
ing information. The wiring information includes
wiring diagrams, proper wire and connector repair

Fig. 3 Gauges & Indicators

1 - AIRBAG INDICATOR

16 - SEATBELT INDICATOR

2 - TACHOMETER

17 - ABS INDICATOR

3 - LEFT TURN INDICATOR

18 - MULTI-FUNCTION INDICATOR PLUS/MINUS SWITCH
PUSH BUTTONS

4 - SPEEDOMETER

19 - MULTI-FUNCTION INDICATOR (INCLUDES: CLOCK, GEAR
SELECTOR INDICATOR, ODOMETER, TRIP ODOMETER, EN-
GINE OIL LEVEL DATA, AMBIENT TEMPERATURE INDICATOR
[OPTIONAL], & ACTIVE SERVICE SYSTEM [ASSYST] ENGINE
OIL MAINTENANCE INDICATOR [OPTIONAL])

5 - TRACTION CONTROL INDICATOR

20 - MULTI-FUNCTION INDICATOR MODE (MILES [KILOME-
TERS]/TIME) SWITCH PUSH BUTTONS

6 - RIGHT TURN INDICATOR

21 - COOLANT LOW INDICATOR

7 - ENGINE TEMPERATURE GAUGE

22 - BRAKE INDICATOR

8 - FUEL GAUGE

23 - OIL LEVEL INDICATOR

9 - WAIT-TO-START INDICATOR

24 - BRAKE WEAR INDICATOR

10 - WASHER FLUID INDICATOR (OPTIONAL)

25 - WATER-IN-FUEL INDICATOR

11 - CONSTANT ENGINE SPEED (ADR) INDICATOR (OPTION-
AL)

26 - CHARGING INDICATOR

12 - LOW FUEL INDICATOR

27 - HIGH BEAM INDICATOR

13 - TRACTION CONTROL MALFUNCTION INDICATOR

28 - PARK BRAKE INDICATOR

14 - MALFUNCTION INDICATOR LAMP

29 - FUEL FILTER CLOGGED INDICATOR

15 - ELECTRONIC STABILITY PROGRAM (ESP) INDICATOR
(OPTIONAL)

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INSTRUMENT CLUSTER

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procedures, further details on wire harness routing
and retention, as well as pin-out and location views
for the various wire harness connectors, splices and
grounds.

The EMIC modules for this model are serviced only

as complete units. The EMIC module cannot be
adjusted or repaired. If a gauge, an LED indicator,
the multi-fuction indicator LCD unit, an electronic
tone generator, the electronic circuit board, the cir-
cuit board hardware, the cluster overlay, the cluster
housing, the cluster hood, the cluster lens, or the
cluster rear cover are damaged or faulty, the entire
EMIC module must be replaced.

OPERATION

The ElectroMechanical Instrument Cluster (EMIC)

is designed to allow the vehicle operator to monitor
the conditions of many of the vehicle components and
operating systems. The gauges, meters and indicators
in the EMIC provide valuable information about the
powertrain, fuel and emissions systems, cooling sys-
tem, lighting systems, safety systems and many
other convenience items. The EMIC is installed in
the instrument panel so that all of these monitors
can be easily viewed by the vehicle operator when
driving, while still allowing relative ease of access for
service. The microprocessor-based EMIC hardware
and software uses various inputs to control the
gauges and indicators visible on the face of the clus-
ter. Some of these inputs are hard wired, but many
are in the form of electronic messages that are trans-
mitted by other electronic modules over the Control-
ler Area Network (CAN) data bus network. (Refer to
8 - ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/COMMUNICATION - OPERATION).

The EMIC microprocessor smooths the input data

using algorithms to provide gauge readings that are
accurate, stable and responsive to operating condi-
tions. These algorithms are designed to provide
gauge readings during normal operation that are con-
sistent with customer expectations. However, when
abnormal conditions exist such as high coolant tem-
perature, the algorithm can drive the gauge pointer
to an extreme position and the microprocessor can
sound a chime through the on-board audible tone
generator to provide distinct visual and audible indi-
cations of a problem to the vehicle operator. The
instrument cluster circuitry also provides audible
turn signal and hazard warning support by emulat-
ing the “ticking” sound associated with a conven-
tional electro-mechanical flasher using a contactless
relay. The relay will also provide an indication of a
turn signal failure by sounding at double the usual
frequency. Each audible warning is provided to the
vehicle operator to supplement a visual indication.

The EMIC circuitry operates on battery current

received through a non-switched fused B(+) circuit,
and on a fused ignition switch output circuit. The

EMIC circuitry is grounded through a ground circuit
and take out of the frame wire harness with an eye-
let terminal connector that is secured to a stud by a
nut at a ground location on the dash panel just for-
ward of the instrument cluster. Separate switched
ground inputs from the key-in ignition switch and
the front door jamb switches provide wake-up signals
to the EMIC circuitry. This arrangement allows the
EMIC to provide some features regardless of the igni-
tion switch position, while other features will operate
only with the ignition switch in the On position.

Proper diagnosis and testing of the EMIC, the

CAN data bus, the data bus electronic message
inputs to and outputs from the EMIC, as well as the
retrieval or erasure of a Diagnostic Trouble Code
(DTC) requires the use of a diagnostic scan tool.
Refer to the appropriate diagnostic information. See
the owner’s manual in the vehicle glove box for more
information on the features, use and operation of the
EMIC.

GAUGES

All gauges receive battery current through the

EMIC circuitry only when the instrument cluster
detects the ignition switch is in the On position. With
the ignition switch in the Off position, battery cur-
rent is not supplied to any gauges and the EMIC cir-
cuitry is programmed to move all of the gauge
needles back to the low end of their respective scales.
Therefore, the gauges do not accurately indicate any
vehicle condition unless the ignition switch is in the
On position.

All of the EMIC gauges are air core magnetic

units. Two fixed electromagnetic coils are located
within each gauge. These coils are wrapped at right
angles to each other around a movable permanent
magnet. The movable magnet is suspended within
the coils on one end of a pivot shaft, while the gauge
needle is attached to the other end of the shaft. One
of the coils has a fixed current flowing through it to
maintain a constant magnetic field strength. Current
flow through the second coil changes, which causes
changes in its magnetic field strength. The current
flowing through the second coil is changed by the
EMIC circuitry in response to messages received over
the CAN data bus. The gauge needle moves as the
movable permanent magnet aligns itself to the
changing magnetic fields created around it by the
electromagnets.

Proper diagnosis and testing of the gauges, the

CAN data bus and the electronic data bus message
inputs to the EMIC that control each gauge require
the use of a diagnostic scan tool. Refer to the appro-
priate

diagnostic

information.

Specific

operation

details for each gauge may be found elsewhere in
this service information.

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INSTRUMENT CLUSTER

8J - 5

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 “+” (plus) and “–” (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 the

transmission 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.

• Airbag Indicator Driver

• Ambient

Temperature

Sensor

Signal

(Optional)

• Brake Wear Indicator Sense

• Charging Indicator Driver

• Coolant Level Switch Sense

• Front Door Jamb Switch Sense

• Fuel Level Sensor Signal

• Fused B(+)

• Fused Ignition Switch Output

• High Beam Indicator Driver

• Key-In Ignition Switch Sense

• Left Turn Signal

• Park Brake Switch Sense

• Right Turn Signal

• Seat Belt Switch Sense

• Washer 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:

• Engine Running Relay Control

• Panel Lamps Driver
Refer to the appropriate wiring information for

additional details.

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