Power windows (PW [EFH]), function (MODEL 204.0/2 up to Model Year 8) - GF72.29-P-0003CW

MODEL 204.0/2 up to Model Year 8

General information

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

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

The power window function comprises the following partial functions:

Manual raising and lowering
Automatic raising and lowering
Child safety lock
Position detection
Normalization
Denormalization
Anti-pinch protection
Excess force limiter
Adaptation
Thermal fuse
Sequence of priority

Operation possibilities:

Driver side power window and outside mirror adjustment switch group (S20):
The individual windows can be opened and closed via the left front power window switch (S20s1), right front power window switch (S20s2), left rear power window switch (S20s3) and right rear power window switch (S20s4).

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

Active settings triggered by other control points can also be interrupted.
Only the corresponding window can be opened and closed via the passenger side power window switch (S21/2), left rear power window switch (S21/3) and right rear power window switch (S21/4).

Function requirements

Circuit 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)
Power window fully functional

The status of the circuit is stored by the electronic ignition lock control unit (N73) on the interior CAN. The status of the front doors is recognized by the left front door lock (A85) or the 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 stored on the interior CAN.

Manual opening and closing feature

Function prerequisite

Power window normalized

If the power window is denormalized, actuation is only accomplished for t = 0.5 s each time.

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 switch in the driver-side switch group is read in by the left front door control unit via left door LIN.

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

The corresponding 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 request is present or until the window has reached the lower or upper stop (however for a maximum of t = 25 s). The excess force limiter is activated as pinch protection.

Automatic raising and lowering

Function prerequisite

Power window 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 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 is activated during automatic raising.

Function sequence for child safety lock

When child safety lock (child safety lock switch pressed) is active, no actions are produced by actuation of the rear power window switches. Actuations already activated are interrupted immediately.

The status of the child safety lock switch 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 function is activated, the LED in the child safety lock switch is 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.

Depending on the actuation direction, the counter is increased when "opening" and correspondingly decreased when closing" the windows.

The zero position is set by normalization. It is located in the upper lock-up position (window completely closed).

Normalization function sequence

Normalization means learning in the upper mechanical window stop (zero point) into the door control unit.

For this purpose, completely close the window in question with the manual raising function. Continue to hold down power window

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

switch for t > 300 ms when the upper end stop of the window is reached.

The location counter in the door control unit is then set to z = 0.

The power window motors are actuated in intervals of t = 0.5 s

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 maximum window travel.
The door control unit recognizes a location counter status greater than the tolerance above the stored zero position.
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.

Obstruction protection

Function requirements

Power window normalized
Window open (s = 230 mm to 4 mm)

Function sequence for anti-pinch protection

When the door control unit recognizes an increase in the force of F = 160 N over the motion path traveled when rolling up the window or when the Hall sensor signals do not change with a period of t = 150 ms + 20 ms, pinching is recognized. Raising is immediately stopped and the window opens s = 125 mm.

Excess force limiter

Function requirements

Power window normalized

Function sequence for excess force limiter

Manual raising (power window switch actuated to first catch): If the door control unit recognizes pinching, the operation is interrupted. When a new request is present within 2 s, interruption is accomplished again.

When a request is again present within 2 s after the second stop, the window is closed without excess force limiter.

Manual raising (power window switch actuated and hold down beyond first catch):

If the door control unit recognizes pinching, the actuation is interrupted and the window is opened s = 20 mm. If a request is present again within t = 2 s, interruption is accomplished again and the window is then opened s = 20 mm. If, within t = 2 s after the 2nd request a request is recognized again, the actuation is interrupted.

Automatic raising:

If the door control unit recognizes pinching, the actuation is interrupted and the window is opened s = 125 mm. When a new request is present within t= 2 s, the operation is again interrupted and the window is then opened approx. 125 mm.

When a new request is present within t = 2 s after the 2nd request, only manual closing is possible.

If the power windows are not normalized, the excess force limiter is deactivated within t = 2 s following the 2nd actuation. This allows normalization at the upper stop.

Adaptation function sequence

In the event of sluggish windows (window guide, seal), the door control units "learn" the change in the motor force for rolling up the window without reversing after normalization.

For this reason, it may be necessary to roll up the windows a second time manually above the pinching range of s = 230 mm up to the upper stop following normalization when the windows are sluggish.

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 is calculated in consideration of the voltage, current and duration of actuation as well as outside temperature. The switch-off threshold is laid out so that an active actuation is not interrupted. The power window motor is still actuated as long as the request is present or a lock-up position is reached.

Reversing is possible during automatic raising when the excess force limiter is actuated.

Priority function sequence

Driver-side switch group
Remaining power window switches
Actuation via STAR DIAGNOSIS
Close window with PRE-SAFE (with code (299) PRE-SAFE)
Open window with crash ventilation
Convenience opening/closing via transmitter key (A8/1)
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.

Function schematic for power windows (PW), manual/automatic raising/lowering		PE72.29-P-2052-99FAA
Power windows (PW), location of components		GF72.29-P-0003-01CW
Power window (PW), block diagram		GF72.29-P-0003-03CW
Transmitter key, component description	A8/1	GF80.57-P-6010CW
Door lock, component description	A85, A85/1	GF80.20-P-4124CW
Power window motor, component description	M10/3, M10/4, M10/5 and M10/6	GF72.29-P-6030CW
Left front door control unit, component description	N69/1	GF72.29-P-6001CW
Right front door control unit, component description	N69/2	GF72.29-P-6009CW
Rear door control unit, component description	N69/3, N69/4	GF72.29-P-6021CW
Electronic ignition switch control unit, component description	N73	GF80.57-P-6001CW
Driver-side power window switch group and outside mirror adjustment, component description	S20	GF54.25-P-4250CW