SMART Series 451 Service Manual page 85

SN_Typ 451_us.book Seite 84 Freitag, 30. November 2007 1:56 13
Interior
Instrument cluster
In the center of the instrument cluster is the speed-
ometer scale with the multifunction display under-
neath.
On each side is a strip with indicators and warning
displays, as well as the control buttons for the multi-
function display.
The task of the instrument cluster is to provide the
driver with information about the various operating
states and to provide acoustic or visual warnings in
the event of critical operating conditions. It is the
display unit for the vehicle speed and for other
systems. In addition, the instrument cluster computes
the maintenance intervals and shows them in the
multifunction display.
Multifunction display
The task of the multifunction display is to provide the
driver with information about variable changes in the
vehicle, the ambient conditions and the road.
The variable displays include:
• Outside temperature
• Main odometer
• Trip odometer
• Gear indicator (in manual mode)
• Automatic transmission indicator (in automatic
mode)
• Fuel reserve indicator (US gal)
• Maintenance interval display with symbol
• Fuel level and reserve indicator
• Clock
84 Introduction of the smart fortwo, Model Series 451
The instrument cluster is a device on the data
bus/CAN bus in the overall network. Most of the
signals are transmitted or received over CAN. The
following signals are supplied to the instrument
cluster over direct lines:
• Signal from outside temperature indicator
temperature sensor
• Signal from "Fanfare horns and airbag clock spring
contact" (only on variant with SAL).
The vehicle speed is displayed by an electronic
speedometer that is driven by a stepper motor. The
ESP control unit reads the information for the speed
display from the wheel speed sensors in the form of
signals, and forwards it over CAN to the instrument
cluster. The instrument cluster processes the
incoming signals and uses them to calculate the
vehicle speed and distance traveled.
Multifunction display
P54.32-5677-00