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Emergency Running Programs for the Easytronic (F13
MTA/F17+MTA)
Note: The purpose of
the emergency running programs is to guarantee the ability of the
vehicle to be used insofar as is possible. This takes place, even
if there is a fault, in a manner which is not critical for the
driver. If certain signals are missing it is sufficient to draw on
substitute/reference values, an emergency program is activated for
other signals, if they are not available to the Easytronic control
unit, or the vehicle is shut down. The sections below describe how
the vehicle behaves, depending on the emergency running program
active. A distinction is made between faults with fault memory
entries and faults without fault memory entries.
Emergency running program "Gearbox actuator shut
down"
- It is no longer possible to change gear
- The gear remains active which was selected when the fault
occurred.
- The clutch opens if an attempt is made to change into another
gear.
Emergency running program "clutch actuator and
gearbox actuator control shut down"
- The clutch actuator is frozen in the current position.
- It is no longer possible to change gear
- The gear remains active which was selected when the fault
occurred.
- The engine stalls on stopping.
- The clutch can "slip" at high acceleration.
Emergency Program "Torque Tracking Off"
- As a consequence of the fact that tracking is no longer
present, the clutch only goes to the positions "fully open" or
"fully closed". In normal operation, the clutch position is always
dependent on the current engine torque (clutch characteristic curve
torque/path). If the vehicle is in manual gear change mode, the
reaction to the intended manual gear change takes somewhat longer
than normal.
Emergency Running Program "Hill Detecting Off"
- No further hill detection by the software takes place (either
uphill nor downhill), otherwise normal operation is present. The
vehicle changes gear more frequently than normal in hilly
areas.
Emergency Running Program "Clutch Adaptation
Off"
- The contact point and friction coefficient adaptation is
switched off by the emergency running program "Clutch adaptation
off". It can then be possible that the contact point of the clutch
begins to wander and is not tracked in the software. This can cause
the comfort of the ride to suffer. In normal driving mode the
parameters are adapted cyclically.
Emergency Running Program "Emergency Run 1"
- Change-over procedure from 1st to 2nd gear takes place very
early.
- Change-over procedure 2/3 and 3/4 from 4700 rpm.
- Engaging 5th gear is prevented.
- All changing down procedures take place very late (just above
idling speed).
- Only automatic mode is active, manual gear change
inactive.
Emergency Running Program "Emergency Run 2"
- Change-over procedure from 1st to 2nd gear takes place very
early.
- Change-over procedure 2/3 and 3/4 from 4000 rpm.
- Engaging 5th gear is prevented.
- All changing down procedures take place very late (just above
idling speed).
Emergency Running Program "Selector Lever
Emergency Run"
- If the selector lever sends implausible signals when the
vehicle is in motion (serial and/or redundant),then the procedure
is as follows: as long as the speed of the vehicle is less than x
km/h (currently 5 km/h), the old selector lever is retained. Below
this speed threshold, "N" is specified. The purpose of this
emergency running program is to bring the vehicle to a standstill
safely. The control unit does not detect any valid selector lever
signals and "N" is then the only safe position ("F" in the
display).
Emergency running program "push button fault
Requirements from push buttons are ignored. This applies until
the next ignition off/on phase if the P 1723 is found to be faulty.
Even if the fault memory entry is reset (not present), the push
buttons do not become active again until after ignition off/on.
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