GF72.29-P-0003FL Power Windows (PW (EFH)), Function

GF72.29-P-0003FL Power Windows (PW [EFH]), Function

Function requirements, general
^ No overvoltage or undervoltage
^ C. 15R ON or c. 15 ON or
^ Run-on time active (up to t = 5 min. after circuit 15R Off, if front doors are not yet open)

The electronic ignition lock control unit (N73) transmits the circuit status c. 15 via the interior CAN (CAN B). The door status is recognized by the left front door lock (A85) or right front door lock (A85/1) read in by the left front door control unit (N69/1) or right front door control unit (N69/2) and transmitted via the interior CAN.

Power windows (PW), general
The side windows in the front and rear doors can be opened and closed with the power windows.

The convenience feature is a possibility to open and close the side windows from one central control point. The convenience features are described in the separate convenience feature (CF) function.

Operation possibilities:
- Driver side power window and outside mirror adjustment switch group (S20):
- Left front power window switch (S20s1)
- Right front power window switch (S20s2)
- Left rear power window switch (S20s3)
- Right rear power window switch (S20s4)
- Passenger-side power window switch (S21/2)
- Left rear power window switch (S21/3)
- Right rear power window switch (S21/4)

Press and hold down power window switch to perform a manual function.
To start an automatic function it is sufficient to momentarily actuate beyond the catch point.
Actuation takes places for as long as the corresponding request is maintained or until the side window reaches the lower or upper stop. Each actuation is limited to a maximum of t = 25 s.

Depending on priority, active power window adjustments can be aborted by the other control points.
Control of the rear power window switch can be inhibited via the rear side window child safety lock switch (S20s5)

The power window system comprises the following partial functions:
^ Function sequence for manual raising and lowering
^ Function sequence for automatic raising and lowering
^ Function sequence for child safety lock
^ Function sequence for position recognition
^ Function sequence for normalization
^ Function sequence for denormalization
^ Function sequence for excess force limiter
^ Function sequence for anti-pinch protection
^ Function sequence for thermal protection
^ Priority function sequence

Additional function requirements for manual raising and lowering
^ Child safety lock switched off (only for rear window)

Function sequence for manual raising and lowering
Actuate and hold down corresponding power window switch to the first catch point or beyond in the opening or closing direction.

The position of the power window switches in the driver side switch group is read in by the left front door control unit via left front door LIN (LIN B5).

The switch positions of the passenger and rear door power window switch are read in by the right front door control unit, le rear door control unit (N69/3) or right rear door control unit (N69/4).

The door control unit then actuates the corresponding:
- Left front door power window motor (M10/3),
- Right front door power window motor (M10/4),
- Left rear door power window motor (M10/5) or
- Right rear door power window motor (M10/6).

Actuation is performed as long as the corresponding request is present or the lower and upper stop are reached.
The duration of actuation is limited to max. t = 25 s.

Additional function requirements for automatic raising and lowering
^ Power windows normalized
^ Child safety lock switched off (only for rear window)

Function sequence for automatic raising and lowering
The corresponding power window switch must be actuated just beyond the first catch point in the opening or closing direction and then released.

The further function sequence corresponds to the manual and raising and lowering function, only actuation of the power window motors is stopped automatically when the lower or upper stop is reached. The anti-pinch protection function is always active during automatic raising.

Function sequence for child safety lock
When child safety lock is active, no actions are produced by actuation of the left and right rear power window switches Actuations already activated are interrupted immediately. The status of the rear side window child safety lock switch is read in by the left front door control unit via front left door LIN and transmitted to the rear door control units via interior CAN.
If the child safely lock function is activated, the LED in the rear side window child safety lock switch is on.

If the position of the rear side window child safety lock switch can no longer be read with certainty, the child safety lock function is regarded as permanently switched on.

Function sequence for position recognition
The location counter in the door control unit in question evaluates the signals from the Hall sensor on the power window motors.

The zero position is the upper stop (side window fully closed) and is set by the normalization procedure.
Depending on the actuation direction, the counter is increased when "opening" and correspondingly decreased when "closing" The side windows.

Normalization function sequence
Normalization means learning in the upper mechanical window stop (zero point) into the door control unit.
For this purpose completely close corresponding side window with the manual raising function. The window lowers approx. s = 20 mm after the request.
A new request for manual closing must be performed within t= 4 s and still be present for t > 300 ms after reaching the upper limit stop.
The location counter in the relevant door control unit is then set to z = 0 and the normalization is completed.

Function sequence for denormalization
The power windows are denormalized under the following circumstances:
- The door control unit recognizes a location counter status greater than the adjustment range.
- The door control unit recognizes a location counter status beyond the tolerance of the zero point stored.
- The door control unit does not recognize Hall sensor signals when the power window motor is actuated.

The cause for denormalization is stored in the corresponding door control unit. When the power windows are denormalized, only the manual raising and lowering functions are possible.

Additional function requirements for excess force limiter
^ Window position in excess force limiter range of s = 4 mm to s = 200 mm window opening size

Function sequence for excess force limiter
If an increase of force is recognized by the door control unit when closing the side window, this is evaluated as pinching. Closing is stopped immediately and the side window is opened automatically approx. s = 20 mm.

The excess force limiter function is activated depending on the type of raising (automatic/manual).
If a new request is present within a short period of time, the sensibility of the excess force limiter is reduced; if pinching is recognized again, actuation is interrupted immediately and the side is opens s = 20 mm.

if a request is again present within a short time after the second stop, the window is closed without excess force limiter.

On power windows which have not been normalized, the excess force limiter is deactivated within a short time after two closing requests. This allows normalization at the upper stop.

Additional function requirements for anti-pinch protection
^ Power windows normalized

Function sequence for anti-pinch protection
If, during raising of a side window, the corresponding door control unit does not recognize a change of the Hall sensor signals, this is evaluated as pinching. Raising is immediately stop and the side window is opens automatically.

When a new request is present within a short time the operation is again interrupted and the window is then opened.
When a new request is present within a short time after the 2nd request, only manual closing is possible.

The anti-pinch protection function is activated depending on the type of raising (automatic/manual).

Function sequence for thermal protection
The protection for the power window motors is guaranteed by a software thermal protection in the corresponding door control unit.
This temperature in the motors is calculated in consideration of the voltage, current and duration of actuation as well as outside temperature.

Priority function sequence
A command with higher priority is performed if a power window function with lower priority is currently active.
The function with lower priority is interrupted first and with the second valid actuation the corresponding function starts.

If a command with lower priority is still present after completion of an operation request with higher priority, the former command is ignored. It is first necessary for the controls to recognize non-actuation of the lower priority command before the corresponding function can be activated.
A command with lower priority cannot affect an active power window function of higher priority.

Priority sequence:
1. Driver-side switch group
2. Remaining power window switches
3. Actuation via diagnosis button
4. Close windows via PRE-SAFE
5. Open window with crash ventilation
6. Convenience opening/closing via transmitter key (A8/1)
7. Convenience opening/closing via recirculated air function