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

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

Function requirements, general
^ Circuit 15R ON or circuit 15 ON
^ Run-on time active (up to t = 5 min. after circuit 15R Off, if 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 doors and the rear side windows can be opened and closed with the power windows.
It is possible to open and close the side windows in the doors manually and automatically.
It is possible to open and close the rear side windows manually and automatically.

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

Model 207.4:
Actuation of the power windows in combination with soft top functions is described in the separate function description "Soft top".

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 corresponding power window switch to perform a manual function.
To activate the automatic adjustment 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.
The duration of actuation is limited to max. t = 25 s.

Control of the rear power window switch can be inhibited via the rear side window child safety lock switch (S20s5)

The function sequences are well-defined with various priorities. 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.

Priority sequence:
1. Driver side power window switch group
2. Remaining power window switches
3. Actuation via diagnosis button
4. Closing side window with PRE-SAFE (further information is given in the PRE-SAFE function description)
5. Opening side window with crash ventilation (further information is given in the supplemental restraint system (SRS) function description)
6. Comfort opening/closing with transmitter key (A8/1) (further information is given in the convenience feature (CF) function description)
7. Comfort opening/closing via air recirculation function (further information is given in the convenience feature (CF) function description)

The power window system comprises the following partial functions:
^ Function sequence for normalization
^ Function sequence for manual raising and lowering
^ Function sequence for automatic raising and lowering
^ Function sequence for short stroke
^ Function sequence for excess force limiter
^ Function sequence for lockup recognition
^ Function sequence for thermal protection

Function sequence for normalization
Normalization means learning in the upper mechanical side window stop (zero point) into the corresponding front door control unit or rear door control unit (N22/6).
For this purpose completely close corresponding side window with the manual raising function. The side 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 is set to z = 0 in the responsible front door control unit or rear door control unit and the normalization procedure is completed.
The location counter in the corresponding front door control unit evaluates the signal from the Hall sensor integrated into the left front door power window motor (M10/3) or right front door power window motor (M10/4). The location counter in the rear door control unit evaluates the signals from the Hall sensor integrated into the left rear power window motor (M10/5) or right rear power window motor (M10/6)

Depending on the actuation direction, the counter status is increased when "opening" and correspondingly decreased when "closing" the side window

The ratio between counter status and armature rotations of the power window motor is four to one.

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

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

Normalization is a basic requirement to use the entire power window functions

Additional function requirements for manual raising and lowering
^ 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. 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.

The requirements for the left power window switch in the driver side switch group are read in by the left front door control unit via the left door LIN (LIN B5).

The requirements for the passenger side power window switch is read in by the right front door control unit. The requirements for the left rear power window switch and right rear power window switch is read in by the rear control unit.

The corresponding front door control unit actuates the following components:
- Left front door power window motor
- Right front door power window motor

The rear door control unit actuates the following components:
- Left rear power window motor
- Right rear power window motor

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

automatic raising is not possible on the rear side windows.

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.

The side window is moved to the short stroke position when the window raising operation is active and the corresponding door is opened simultaneously. The side window is moved to the end position when the window is raising and the corresponding door is closed simultaneously.
The side window is moved to the short stroke position when the window is raising and a door is open.
When the window is lowering, the side window is moved to the end position regardless of the corresponding door status

Additional function requirements for short stroke
^ Power windows normalized

Function sequence for short stroke
The short stroke function comprises the following partial functions:
^ Function sequence for short stroke for side window in door
^ Function sequence for short stroke for rear side window

Function sequence for short stroke for side window in door
When a door is opened, the side window in the door is lowered to the short stroke position (approx. 4 mm).
After closing the door, the side window is closed again. Control is performed from the corresponding front door control unit.

Function sequence for short stroke for rear side window
When a door or a side window is opened, the associated rear side window is lowered automatically to the short stroke position
- approx. s = 4 mm (with code (494) USA version)
- approx. s = 12 mm (not with code (494) USA version)

The short stroke position of the rear side windows can be programmed in the rear control module using the national version

After closing the door or the side window, the associated rear side window is closed again.
The requests are transmitted by the corresponding front door control to the rear door control unit via the interior CAN. The rear power window motors are actuated by the rear control unit.

Additional function requirements for excess force limiter
^ Side window open (s = 4 mm to 230 mm)
^ Power windows normalized

Function sequence for excess force limiter
The front door control units and rear door control unit recognize an increase in force by monitoring the power consumption when closing the side windows (anti-pinch protection)

Manual raising function:
1st actuation: Stopping at a force of FM1 = 100 N + 15 N, when power window switch is released, side window opens s = 20 + 5 mm

2nd actuation: Stopping at a force of FM2) = FM1= + 30 N, when power window switch is released, side window opens s = 20 + 5 mm

3rd actuation: Closing without excess force limiter, interruption when power window switch is released

Automatic raising function:
1st actuation: Stopping at a force of FA1 = 60 N - 10 N and side window opens s = 125 + 5 mm

2nd actuation: Stopping at a force of FA2 = FA1 +30 N and side window opens s = 125 + 5 mm

3rd actuation: Only manual raising possible

Adaptive excess force limiter:
The system is designed adaptively to prevent mechanical sluggishness in the window operation being evaluated as pinching This means, that the system recognizes sluggishness and calculates an increased force for the next request (additional F = 10 N).
This ensures a constant speed when raising and lowering the power windows even under conditions such as advanced wear or outer influences such as moisture and icing. The adaptation is limited to a maximum value of F = 80 N.

Mechanical vibrations caused by bad road conditions are not recognized as pinching and do not lead to reversal of the rising window. The "bad road recognition" required for this purpose is activated starting at a speed of > 8 km/h.
The instrument cluster (A1) calculates the vehicle speed from the wheel speed and provides this information to the interior CAN.

The "poor road recognition" is a part of the pinch protection algorithm and is calculated by the corresponding front door control unit or rear door control unit from internal data.

additional function requirements for blockage detection
^ Side window open (s = 4 mm to 230 mm)
^ Power windows normalized

Function sequence for lockup recognition
If one of the following operations is recognized by the front door control unit or rear door control unit when raising the side window, the corresponding actuation is interrupted and the side window is lowered slightly (reversed):
- Increase in force of F > 160 N
- Hall sensor signals not changed within t = 150 ms + 20 ms

For details on reversing, see: "Function sequence for excess force limiter"

Function sequence for thermal protection
The power window motors are protected by a software-based thermal protection function in the respective front and rear door control unit. The software simulates temperature characteristics depending on the operating time. Parameters required for this are determined in tests and are stored in the corresponding door control unit.

The permissible ambient temperature range of the power window motor is: - 40 °C to + 85 °C