Power windows (PW [EFH]), function (MODEL 204 as of model year 2009 /YoM 08) - GF72.29-P-0003CE

MODEL 204 as of model year 2009 /YoM 08

Fig 1: Identifying Power Windows CAN Communication Diagram

Courtesy of MERCEDES-BENZ USA

Function requirements, general

No overvoltage or undervoltage
Circuit 15R "ON" or circuit 15 "ON" or
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 transmits the circuit status circuit 15 via the interior CAN. The status of the doors is recognized by the left door lock or right door lock, read in by the left door control unit or right rear door control unit and transmitted over the interior CAN.

Power windows, general

The front side windows in the doors can be opened and closed with the power window lifters.

Additional convenience features are available for opening and closing, allowing the side windows to be opened and closed from one 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:
- Left front power window switch (S20s1)
- Right front power window switch (S20s2)
Passenger-side power window switch
Left rear power window switch (model 204.0/2/9)
Right rear power window switch (model 204.0/2/9)

Manual actuation is possible by pressing and holding down the corresponding power window switch for the side window to be opened.

To activate the 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.

The function sequences are assigned different priorities depending on the requirements. 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:

Driver-side switch group
Remaining power window switches
Actuation via diagnosis button
Open window with crash ventilation
Convenience opening/closing via transmitter key (A8/1)
Convenience opening/closing via recirculated air function

The power window function 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 excess force limiter

Function sequence for normalization

Normalization is teaching in the upper mechanical stop (zero point) of the side window into the corresponding front door control unit or rear door control unit (on model 204.0/2/9). For this purpose completely close corresponding side window with the manual raising function. The window lowers approx. s = 20 mm after the

Function sequence for anti-pinch protection
Function sequence for thermal protection

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 mechanical side window end stop.

The location counter of the corresponding front door control unit or rear door control unit (on model 204.0/2/9) is set to z = 0 and the normalization procedure is terminated.

The location counter of the corresponding front door control unit or rear door control unit (on model 204.0/2/9) valuates the signals of the Hall sensors integrated into the power window motor.

The counter status is increased when "opening" and decreased when "closing" the side windows.

The ratio between the counter reading (z) and the armature rotation of the power window motor (AU) is: i = z : AU = 4 : 1

The power windows are denormalized under the following conditions:

One of the front door control units or rear door control units (on model 204.0/2/9) recognizes a location counter status greater than the maximum adjustment range.
One of the front door control units or rear door control units (on model 204.0/2/9) recognizes a location counter status beyond the zero point tolerance of the stored zero point.
One of the front door control units or rear door control units (on model 204.0/2/9) does not recognize Hall sensor signals when actuating the power window motor.

The cause for the denormalization is stored in the corresponding front door control unit or rear door control unit (on model 204.0/2/9)

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.

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.

Model 204:

The signals from the left front power window switch in the power window switch group and driver side outside mirror adjustment are read in by the left front door control unit via the left door LIN. The left front door control unit then actuates the left front door power window motor. The signals from the passenger side power window switch are read in accordingly by the right control front door unit. The right front door control unit then actuates the left front door power window motor.

Models 204.0/2/9:

The signals from the left rear power window switch are read in correspondingly by the left rear door control unit. The left rear door control unit then actuates the left rear door power window motor. The signals from the right rear power window switch on the right rear power window are read in correspondingly by the right rear control unit.

The right rear door control unit then actuates the right rear door power window motor.

Additional function requirements for automatic raising and lowering

Power windows normalized

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 remaining function sequence corresponds to that of manual raising and lowering.

Actuation of the power window motors is discontinued automatically upon reaching the bottom or top stop. The anti-pinch protection function is always active during automatic raising.

Additional function requirements for excess force limiter

Side window position in area of s = 4 to 230 mm opening width
Power windows normalized

Function sequence for excess force limiter

If, when closing the side window, the corresponding front door control unit or rear door control unit (on model 204.0/2/9) recognizes an increase in force of F > 160 N via power consumption, this is evaluated as pinching. Closing is stopped immediately and the side window is opened automatically approx. s = 20 mm.

The system is designed adaptively to prevent mechanical sluggishness being evaluated as pinching This means that the system recognizes sluggishness by the increased current consumption of the specific power window motor and calculates an additional force of F = 10 N for the next request.

This ensures a constant speed when opening or closing the power windows even in the face of advanced wear or external influences such as moisture and ice. The adaptation is limited to a maximum value of F = 80 N.

The excess force limiter function is activated depending on the type of raising (automatic/manual).

If a new request is received immediately thereafter, the sensitivity of the excess for limiter is reduced. If pinching is recognized again, actuation of the power window motor is discontinued and the side window is opened automatically by s = 20 mm.

If a request is present again after the 2nd 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.

Mechanical vibrations caused by bad road conditions are not recognized as pinching and do not lead to reversal of the rising side window. The "bad road recognition" required for this purpose is activated starting at a speed of > 8 km/h.

Additional function requirements for anti-pinch protection

The excess force limiter function is activated depending on the type of raising (automatic/manual).

The side window must reverse before reaching a pinching force of F > 100 N.

Power windows normalized

Function sequence for anti-pinch protection

If the door control unit does not recognize any change in the within t = 150 + 20 ms when closing the side window, this is evaluated as pinching. Raising is immediately stopped and the side is opens s = 20 mm. If a new request is present immediately thereafter, the operation is interrupted again and the window then opened. If a new request is present immediately after the 2nd request, only manual closing is possible.

Function sequence for thermal protection

The protection for the power window motor is guaranteed by a software thermal protection in the corresponding 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

	Electrical function diagram for power windows	PE72.29-P-2050-97FAA
	Overview of system components for power windows (PW)	GF72.29-P-9997CE