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

GF72.29-P-0003LE Power Windows (PW [EFH]), Function
- as of model year 09

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

The circuit status is transmitted by the EIS control unit (N73) to the interior CAN. The status of the front doors is recognized by the left door lock unit (A85) or right door lock unit (A85/1), read in by the left front door control unit (N69/1) or right front door control unit(N69/2) and transmitted to the interior CAN.

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

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.

Driver-side control point:
The following switches are integrated in the driver power window outside mirror and trunk lid switch group (S20/1):
- Left front power window switch (S20/1s1)
- Right front power window switch (S20/1s2)
- Left rear power window and side window roller blind switch (S20/1s3)
- Right rear power window and side window roller blind switch (S20/1s4)
- Child protection switch for rear side windows (S20/1s5)

The side windows can be opened and closed centrally from the driver position with these switches.
Operation can be inhibited via the control points in the rear with the rear side window child safety lock (S20/1s5).

Front passenger control point:
The side window in the passenger door can be opened and closed via the passenger power window switch (S21/2).

Control points in rear:
The following control elements are installed in the rear depending on the equipment:

Vehicles without code (297) Roller sun blinds in rear doors, without code (413) Panoramic glass sunroof with top sliding roof and without code (540) Electric roller sun blind for rear window ):
- Left rear power window switch (S21/3)
- Right rear power window switch (S21/4)

Vehicles with code (297) Roller sun blinds in rear doors, with code (413) Panoramic glass sunroof with top sliding roof or with code (540) Electric roller sun blind for rear window ):
- Left rear door power window/roller blind switch group (S21/21)
- Right rear power window and side window roller blind switch (S21/21s1)
- Left rear power window and side window roller blind switch (S21/21s2)
- Right rear door power window/roller blind switch group (S21/22)
- Right rear power window and side window roller blind switch (S21/22s1)
- Left rear power window and side window roller blind switch (S21/22s2)

Both sides windows in the rear doors can be opened and closed via the rear door switch groups.

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 anti-pinch protection
^ Function sequence for thermal protection
^ Priority function sequence

Additional function requirements for manual raising and lowering
^ Power windows normalized
^ Child safety lock switched off (only for rear side 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 positions of the power window switch in the driver power window outside mirror and trunk lid switch group are read in by The left front door control unit via the front door LIN.
The switch position of the passenger power window switch can be read in directly by the right door control unit.
The positions of the rear power window switch are read in directly by the left rear door control unit (N69/3) or right rear door control unit (N69/4).
The signals from the rear door power window switch group are transmitted to the corresponding rear door control unit via the rear door LIN.

The left front door control unit actuates the left rear power window motor (M10/3), the right front door control unit actuates the right front power window motor (M10/4).
The left rear door control unit actuates the left rear power window motor (M10/5) and the right rear door control unit actuates the right rear power window motor (M10/6).

Actuation takes places for as long as the corresponding request is maintained or until the side window reaches the lower or upper stop.

The duration of the actuation for the power window motors is limited to max. t = 25 s.

Additional function requirements for automatic raising and lowering
^ Power windows normalized

Function sequence for automatic raising and lowering
Actuate corresponding power window switch momentarily beyond the first catch point in the opening and closing direction. The remaining function sequence corresponds to that of manual raising and lowering. The anti-pinch protection function is always active during automatic raising.

Function sequence for child safety lock
The status of the child safety lock switch in the rear side window is read in by the left door control unit via the left door LIN and transmitted to the rear door control units via interior CAN. If the child safety lock is activated, the LED in the rear side window child safety lock comes on and operation via the rear power window switch is inhibited.

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 sensors on the power window motors. The zero position is the upper stop (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 window.

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. After releasing the power window switch, the side window lowers approx.approx. s = 20 mm. The power window switch must be actuated again within t = 4 s and the switch must be actuated for another t > 300 + ms upon reaching the upper end position of the window. The location counter in the responsible door control unit is then set to z = 0.

Function sequence for denormalization
The following functions denormalize the power windows
- A door control unit recognizes a location counter status greater than the maximum adjustment range.
- The door control unit recognizes a location counter status beyond the tolerance of the zero point stored.
- A door control unit recognizes no or faulty Hall sensor signals or an incorrect rotation direction when actuating the power window motor.
- The supply voltage (c. 30) for one door control unit remains off for t = 60 s.

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 anti-pinch protection
^ Power windows normalized

Function sequence for anti-pinch protection
If the force does not increase or the Hall sensor signals do not change when raising the side window of the door control unit or rear control unit, this is evaluated as pinching. Raising is immediately stopped and the side opens automatically..

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

The ant-pinch protection function comprises the following partial functions:
^ Function sequence for anti-pinch protection after manual actuation
^ Function sequence for anti-pinch protection after automatic actuation

Additional function requirements for anti-pinch protection after manual actuation
^ Side window open s = 3 mm to s = 230 mm

Function sequence for anti-pinch protection after manual actuation
Anti-pinch protection is activated during manual raising and operates in three stages of different intensity.
If a door control unit or the rear control unit recognizes pinching (overload), actuation is interrupted and the side window is opened when the power window switch is released for a maximum of s = 125 mm (programmable).
If a new request is present within t = 2 s, the response time of the excess force limiter is increased; if pinching is recognized again the actuation is interrupted and the side window is opened s = 20 mm. If a new request is present from t = 5 s to t = 10 s after the 2nd stop, the window is closed without the excess force limiter.

Function sequence for anti-pinch protection after automatic actuation
If a front door control unit or a rear door control unit recognizes pinching, the actuation is interrupted and the side window is opened immediately.
When a new request is present within t = 2 s, the operation is again interrupted and the window is then opened.
When a new request is present within 2 s after the 2nd request, only manual closing is possible.

The excess force limiter is disabled when the window is actuated a second time within t = 2 s on non-normalized power windows. This allows normalization at the upper stop

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. The temperature of the power window motor bearings is calculated according to the voltage, power, actuation duration and outside and inside temperature.
After a certain threshold value is reached, the corresponding power window motor is actuated only until the request is no longer present or the end stop is reached.
It is possible to reactuate the power window motor after a cooling phase calculated by the left door control unit.

Priority function sequence
1. Alarm closing
2. Driver-side control point
3. Passenger control point or control points in rear
4. Actuation for handicapped vehicle (special equipment)
5. Close windows via PRE-SAFE
6. Open window with crash ventilation
7. Actuation with diagnosis
8. Central opening/closing via Keyless-Go (with code (889) Keyless Go)
9. Central opening/closing via transmitter key (A8/1)
10. Convenience opening/closing via recirculated air function

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.