(Power Windows (PW (EFH)), Function - GF72.29-P-0003GR)
MODEL 166
Up To Model Year 2016
Function requirements, general
- No overvoltage or undervoltage
- Circuit 15R ON or run-on time active (up to t = 5 minutes after circuit 15R OFF and front door still not open)
The electronic ignition lock control unit transmits the terminal status 15 via the interior CAN.
The left front door control unit captures the status of the left front door and sends this via the interior CAN.
The right front door control unit captures the status of the right front door and sends this 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
- Left front power window switch
- Right front power window switch
- Left rear power window switch
- Right rear power window switch
- Passenger-side power window switch
- Left rear power window switch
- Right rear power window switch
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 (maximum t = 25 s) as the corresponding request is pending or until the side window reaches the lower or upper stop. Control of the rear power window switch can be inhibited via the rear side window child safety lock switch.
The priority of possible functions depends on their requirement. A command with higher priority is performed if a function with lower priority is currently active. A lower priority function is interrupted first and is accomplished only after the second valid request. 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 request before the corresponding function can be activated.
Priority sequence:
- Driver-side power window and outside mirror adjustment switch group
- Remaining power window switches
- Actuation via diagnostic tester
- Close windows via PRE-SAFE
- Open window with crash ventilation
- Comfort opening/closing via central locking (CL)
- Convenience opening/closing via recirculated air function
The power window functions comprise 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 automatic reserving function
- Function sequence for overheating protection
- Function sequence - child safety lock
The electric pop-out windows function (in model 166.8) is described in a separate document "Electric pop-out windows, function".
The priority of possible functions depends on their requirement. A command with higher priority is performed if a function with lower priority is currently active. A lower priority function is interrupted first and is accomplished only after the second valid request. 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 request before the corresponding function can be activated.
Function sequence for normalization
Normalization is the basis for assigning the momentary positions to the positions sensed by the corresponding front door control unit and rear door control unit of the side window.
To this end, the corresponding side window must be completely closed manually, and the power window switch must continue to be pressed for approx. t = 300 ms. If the power window switch is then released, the side window lowers approx. s =20 mm. The side window must then be closed completely within t= 4 s and the power window switch must be actuated for another t > 300_ms.
The corresponding signal path is described in the chapter "Manual raising and lowering".
The location counter in the relevant front door control unit or rear door control unit is set to z = 0 and normalization is completed. The location counter evaluates the signals from the Hall sensor integrated in the corresponding power window motor. The counter status is increased when opening and decreased when closing the side windows.
The ratio between counter status and armature rotations of the power window motor is 4: 1.
The power windows are denormalized under the following conditions:
- Position counter status greater than maximum adjustment range
- Position counter status going beyond zero point tolerance for stored zero point
- No Hall sensor signals when power window motor in question is actuated
The cause of denormalization is stored in the applicable front door control unit or rear door control unit. When the power windows are denormalized, only the manual raising and lowering functions are possible.
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 (max. t = 25 s) as the corresponding request is present or the lower and upper limit stops are reached.
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 directly by the right control front door unit. The right front door control unit then actuates the left front door power window motor.
The signals from the rear power window switch are read in by the corresponding rear door control unit. The rear door control unit actuates the left rear power window motor, the right rear door power window motor 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 to the greatest extent. Actuation of the power window motors is discontinued automatically upon reaching the bottom or top stop. The automatic reserving function is 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
The excess force limiter function operates when the window is raised automatically or manually, however, at different sensitivity levels (escalation stages). The power consumption of the power window motor serves as a reference for excessive force.
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 individual escalation stages depend on the operating request and history and are shown in the table below.
| Manual closing | 1. Actuation (escalation stage 1) | 2nd actuation (escalation stage 2) | 3rd actuation (escalation stage 3) |
|---|---|---|---|
| Holding power window switches | Stops at F = 100 N + 15 N | Stops at F = 130 N + 15 N | Actuation remains active |
| Releasing power window switches | Reversing s = 20 mm + 5 mm | Reversing s = 20 mm + 5 mm | Actuation stopped |
| Automatic closing | |||
| Releasing power window switches | Stop at F = 60 N - 10 N; reversing s = 125 mm + 5 mm | Stop at F = 80 N - 10 N; reversing s = 125 mm + 5 mm | Only manual raising possible |
If the power window switch is actuated again within t ≤ 2 after completion of the reversing maneuver, the status changes. When the power window switch is actuated again after a time of t = 2 s, escalation stage 1 (1st actuation) is started.
If pinching is recognized during automatic raising triggered by the comfort closing function via the air recirculation function, the corresponding front door control unit or rear door control unit starts with escalation stage 1 (1st actuation).
If pinching is recognized during automatic raising, triggered by the Keyless-Go function (with code (889) KEYLESS-GO) or side window closing function by PRE-SAFE (with code (299) PRE-SAFE® system), the corresponding front door control unit or rear door control unit initiates escalation stage 2 (2nd actuation).
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.
| Electrical function diagram for power windows | PE72.29-P-2050-97NAA | ||
| Overview of system components for power windows | GF72.29-P-9993GR |