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Control unit with display in dash panel insert
The upshift indicator
Function
The upshift indicator in the driver information sys-
tem is a new function designed to help the driver to
reduce fuel consumption. The function is integrated
in the engine management software. It is featured
on all petrol and diesel models with manual gear-
box.
As modern vehicle engines deliver high torque even
at low rpm, it is often possible to drive in a higher
gear.In this case, a gearshift recommendation is
indicated to the driver via the driver information sys-
tem. The gearshift recommendation may involve
skipping a gear.
The actual gear position is indicated continuously in
the driver information system. This information is
derived from the actual engine speed and road
speed signals. Neither the actual gear position nor
any gearshift recommendations are indicated while
the clutch is actuated (for longer than 2 seconds).
No gearshift recommendation is given when the
engine is operating at full throttle either.
Normally no gearshift recommendation is issued
when the vehicle is in overrun. However, if the
engine speed drops below a critical threshold, a rec-
ommendation to shift down a gear will be given.
To implement the "upshift indicator" function, the
engine control unit also requires information from
the steering angle sender G85, the ABS control unit
J104 and the convenience system control unit J393.
The engine control unit receives this information via
CAN bus.
393_043
Upshift indicator in Midline or Highline dash panel insert
Indicator
The gearshift recommendation computed by the engine control unit is transmitted via CAN bus to the dash
panel insert and displayed in the driver information system. There are two possible states of the display:
1 The actual gear position is displayed with or without a gearshift recommendation.
2 No display. This is the case if the clutch is actuated for longer than two seconds or if the driver has deac-
tivated the function on the MMI.
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