Self-Study Program

58
367_114
Certain adaption conditions have to be met so that
adaptions can be performed:
The ATF temperature must be between 66 °C and
110 °C.
Engine load must be within a defined range (very
low engine load or low accelerator pedal angle).
No faults registered in the fault memory of the
gearbox control unit
A defined driving state (e.g. certain adaptions
are only performed when the vehicle is
stationary and when the engine is running at
idling speed)
Good road conditions (no uphill gradient or
downhill gradient, straight road)
The gearbox adaption status is established over
a prolonged period of time in service. A further
feature of the gearbox control unit is that the
adaption frequency is reduced with increasing
mileage. This means that the adaption frequency
of a gearbox with low mileage or with cancelled
adaption values is very high. On the other hand,
gearboxes with high mileage has longer adaption
intervals.
Gearbox control unit
A
Pre-filling
Quick filling time
(quick filling)
Filling pressure
B
Shift pressure
C
Holding pressure
The following aspects of the gearshift sequence are
adapted:
Quick filling time (pre-filling)
Filling pressure (pre-filling)
Shift pressure (engaging and disengaging
clutch)
Holding pressure
Explanation / definition of the individual adaption
ranges:
Quick filling time = period during which increased
pressure is applied to the clutch in order to engage
the clutch assembly and fill the clutch cylinder
chamber.
Filling pressure = pressure which is required to
compress the clutch plate assembly to the point
where the clutch just comes into engagement
but a significant amount of this torque is still
not transmitted.
Shift pressure = pressure which acts during the slip
phase.
Holding pressure = pressure required to keep the
clutch securely closed.
Adaptions are made during gearshift cycles and
when the vehicle is stationary with the engine
running at idling speed.
Legend
n_mot = engine speed
n_t = turbine speed
m_mot = engine torque
P_zu = engaging clutch
P_ab = disengaging clutch
t = time
A, B, C = adaption range
Upshift under acceleration sequence