3 Series E91 330xi (N52) TOUR
The junction box electronics send the following signals to the instrument cluster:
•
Coolant level (Check-Control message)
•
Washer fluid level (Check-Control message)
•
Fuel level via 2 fuel level sensors (used by instrument cluster to compute the Check-Control message)
•
Parking brake applied (general brake warning lamp)
The junction box is also the gateway between the PT-CAN and the K-CAN. The PT-CAN is used, e.g. for
DME/DDE and DSC messages.
The K-CAN is used, e.g. for terminal control signals from the CAS control unit.
The instrument cluster receives its power supply from the junction box terminals 30 and 31.
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MRS: Multiple restraint system
The multiple restraint system (MRS) is a bus participant on the K-CAN.
The MRS control unit sends the message whether the airbag warning light or seat belt indicator light needs to be
actuated.
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DME or DDE: Digital engine electronics or digital diesel electronics
The DME/DDE supplies the following signals (for example) to the instrument cluster: Engine speed and injection
rate.
The message is sent through the PT-CAN and then through the K-CAN. The DME/DDE also indicates whether
an exhaust-related fault has developed (actuation of emissions warning light).
> On vehicles from 03/2007
Depending on the engine version installed, an automatic engine start/stop system may be fitted. The engine
management controls this function.
If a fault develops in the automatic engine start/stop system, the engine management will generate a
corresponding Check-Control message. The instrument cluster displays the Check-Control message.
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DSC: Dynamic Stability Control
The brake pad wear sensors are connected to the DSC control unit. The DSC also sends further messages to
actuate indicator and warning lights in the instrument cluster:
•
ABS indicator and warning light.
•
DSC indicator and warning light.
•
DTC indicator light.
•
General brake warning light
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EGS: Electronic transmission control
On vehicles with automatic transmission:
A signal from the EGS control unit causes the gear program display or gear indicator in manual mode to be
shown in the LCD display.
On vehicles with manual transmission:
No gear indicator. The area is used (via encoding) for a larger on-board computer function display.
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Cruise control with brake function or active cruise control
On vehicles with 6-cylinder engine and longitudinal dynamic management (LDM control unit):
The set speed is transmitted by the LDM control unit to the instrument cluster on the PT-CAN and K-CAN.
During active cruise control, an additional indicator light is activated as a distinguishing feature for cruise control
with brake function. The distance to the vehicle in front is indicated with 3 bars. The set speed for active cruise
control appears briefly in the LCD display (in addition to permanent display with the moving-disc instrument).
> BMW 3-Series:
SBT Instrument cluster E81, E87, E90, E91, E92, E93
BMW AG - TIS
22.02.2013 01:54
Issue status (12/2007) Valid only until next DVD is issued
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