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

Model 217, 222 

Courtesy of MERCEDES-BENZ USA

Shown on model 222 

Courtesy of MERCEDES-BENZ USA

Shown: model 217 

Function requirements, general 

• No overvoltage or undervoltage
• Circuit 15 run-in time or run-on time active (up to 5 min after circuit 15 OFF and front doors still not opened)

The electronic ignition lock control unit transmits the circuit status of circuit 15 to the front door control units and rear door control units (model 222) or rear control unit (model 217) via the interior CAN.

Power windows (PW), general 

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

The convenience feature is a possibility to open and close the side windows from one central control point.

The side windows can be opened and closed via the following control points:

• Driver-side power window switch group
• Power window switch, front passenger side

On model 222 the rear side windows can be opened and closed additionally via the following control points:

• Left rear door power window switch (except code 297 (Roller sun blinds in rear doors), except code 413 (Panoramic sliding sunroof) and except code 540 (Electric roller sun blind for rear window))
• Right rear door power window switch (except code 297 (Roller sun blinds in rear doors), except code 413 (Panoramic sliding sunroof) and except code 540 (Electric roller sun blind for rear window))
• Left rear door switch group (with code 297 (Roller sun blinds in rear doors), code 413 (Panoramic sliding sunroof) or code 540 (Electric roller sun blind for rear window))
• Right rear door switch group (with code 297 (Roller sun blinds in rear doors), code 413 (Panoramic sliding sunroof) or code 540 (Electric roller sun blind for rear window))

Press and hold down power window switch to catch point to perform a manual function. To start an automatic function it is sufficient to momentarily actuate beyond the catch point.

Actuation takes place for as long as the corresponding request is maintained or until the side windows reach the lower or upper stop. The duration of actuation is limited to max. 25 s.

Model 222

Operation of the rear power windows can be inhibited by the driver 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 request with higher priority is still present after completion of an operation request with higher priority, the former request is ignored. The rest position of this request must first be detected before the corresponding function is activated.

Priority sequence:

1. Driver-side power window switch group
2. Remaining power window switches
3. Actuation via diagnostic tester
4. Close side windows via PRE-SAFE®
5. Open side windows with crash ventilation
6. Convenience opening/closing through central locking
7. Convenience opening/closing via recirculated air function

The power window functions comprise the following partial functions:

• Normalizing 
• Manual raising and lowering 
• Automatic raising and lowering 
• Short stroke (model 217) 
• Child safety lock (model 222) 
• Excess force limiter 
• Lock-up reverse 
• Overheating protection 
• Actuation by PRE-SAFE® 
• Crash ventilation 

Normalizing 

Normalization means teaching in the upper mechanical stop (zero point) into the corresponding front door control unit, rear door control unit (model 222) or rear control unit (model 217). To this end, the relevant side window must be fully closed manually, and the power window switch must continue to be held down for approx. 300 ms. When the power window switch is then released, the side window lowers approx. 20 mm. The side window must now be fully closed once more within 4 s and the power window switch actuated for another 300 ms.

Vehicles up to model year 2018: 

The power window motors are equipped with one Hall sensor each, and its signals are evaluated by the corresponding front door control unit, rear door control unit (model 222) or rear control unit (model 217).

Vehicles as of model year 2018: 

The power window motors do not have any Hall sensors for recording the position. The respective front door control unit, rear door control unit (model 222) or rear control unit (model 217) evaluates the current ripple of the power window motor, which occurs during the rotation, to define the position of the side windows.

The location counter in the respective front door control unit, rear door control unit (model 222) or rear control unit (model 217), which records the adjustment range of the side window, is set to 0. The normalization procedure is completed. 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 four to one.

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

The power windows are denormalized under the following conditions:

• One of the front door control units, rear door control units (model 222) or the rear control unit (model 217) detects a location counter reading greater than the maximum adjustment range.
• One of the front door control units, rear door control units (model 222) or the rear control unit (on model 217) detects a location counter reading that goes beyond the zero point tolerance of the stored zero point.
• One of the front door control units, rear door control units (model 222) or the rear control unit (model 217) does not detect the change in position despite actuation of the respective power window motor.

The cause of the denormalization is stored in the corresponding front door control unit, rear door control unit (model 222) or rear control unit (model 217).

When the power windows are denormalized, only the manual raising and lowering functions are possible.

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. 25 s.

The glass window pane reduces the speed of movement when it runs into the upper seal. As from June 1, 2018, the speed of movement will not be reduced at a vehicle speed > 120 km/h.

Front side window in driver side:

• The signals from the driver-side power window switch in the driver-side power window switch group are read in by the left front door control unit via the left front door LIN. The left front door control unit then directly actuates the left front door power window motor.

Front side window in passenger side:

• The signals from the passenger-side power window switch in the driver-side power window switch group are read in by the left front door control unit via the left front door LIN and transmitted to the right front door control unit via the interior CAN. The right front door control unit then directly actuates the right 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 directly actuates the right front door power window motor.

Rear side window:

Model 222 except code 297 (Roller sun blinds in rear doors), except code 413 (Panoramic sliding sunroof) and except code 540 (Electric roller sun blind for rear window)

• The signals from the rear power window switches in the driver-side power window switch group are read in by the left front door control unit via the left front door LIN and transmitted to the respective rear door control unit via the interior CAN. The corresponding rear door control unit then actuates the rear power window motor directly.
• The signals from the respective rear door power window switch are read in directly by the corresponding rear door control unit. The left rear door control unit directly actuates the left rear power window motor. The right rear door control unit directly actuates the right rear power window motor.

Model 222 with code 297 (Roller sun blinds in rear doors), code 413 (Panoramic sliding sunroof) or code 540 (Electric roller sun blind for rear window)

• The signals from the rear power window switches in the driver-side power window switch group are read in by the left front door control unit via the left front door LIN and transmitted to the respective rear door control unit via the interior CAN. The corresponding rear door control unit then actuates the rear power window motor directly.
• The signals from the power window switch and left rear side window roller sun blind in the left rear door switch group are read in by the left rear door control unit via left rear door LIN. The left rear door control unit then directly actuates the left rear door power window motor.
• The signals from the power window switch and left rear side window roller sun blind in the right rear door switch group are read in by the right rear door control unit via left rear door LIN and transmitted to the left rear door control unit via the interior CAN. The left rear door control unit then directly actuates the left rear door power window motor.
• The signals from the power window switch and left rear side window roller sun blind in the right rear door switch group are read in by the left rear door control unit via right rear door LIN. The right rear door control unit then actuates the right rear door power window motor directly.
• The signals from the power window switch and right rear side window roller sun blind in the left rear door switch group are read in by the left rear door control unit via left rear door LIN and transmitted to the right rear door control unit via the interior CAN. The right rear door control unit then actuates the right rear door power window motor directly.

Model 217:

• The signals from the rear power window switches in the driver-side power window switch group are read in by the left front door control unit via the left front door LIN and transmitted to the rear control unit via the interior CAN. The rear control unit then correspondingly actuates the rear power window motor.

Model 217

The rear power window motors can be operated exclusively via the rear power window switches in the driver-side power window switch group.

Additional function requirements for automatic raising and lowering 

• Power windows normalized

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 automatic reserving function is active during automatic raising.

Additional function requirements for short stroke (model 217) 

• Power windows normalized

Short stroke (model 217) 

When the front door is opened, the side window in the front door and the associated rear side window are lowered to the short stroke position.

After closing the front door, the side windows are closed. The respective front door control unit controls the front side windows and the rear control unit controls the rear side windows.

Short stroke: 

• Front side window approx. 4 mm
• Rear side window approx. 4 mm

The corresponding front door control unit senses the status of the corresponding front door and directly actuates the front door power window motor. The corresponding front side window is lowered to the short stroke position. Then the corresponding front door control unit transmits the request "Actuate short stroke position" to the rear control unit via the interior CAN. The rear control unit then directly actuates the rear power window motor. The corresponding rear side window is lowered to the short stroke position.

Child safety lock (model 222) 

If the child safety lock is switched on (via the rear side window child safety lock switch), it is no longer possible to open or close the rear side windows via the corresponding rear control elements. Actuations already activated are interrupted immediately by the power window motors.

The status of the rear side window child safety lock switch in the driver-side power window switch group is read by the left front door control unit via the left front door LIN. The left front door control unit transmits the status of the child safety lock to the corresponding rear door control unit via the interior CAN.

The rear side window child safety lock switch signals the driver that the child safety lock is activated. To this end, the left front door control unit sends a request to actuate the LED via the left front door LIN to the rear side window child safety lock switch in the driver-side power window switch group.

If the signals 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.

Additional function requirements for excess force limiter 

• Window position in the range from 4 to 230 mm (clear opening)
• Power windows normalized

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 in the side window operation being evaluated as pinching. This means that the system recognizes sluggishness by the increased power consumption of the respective power window motor, and calculates an additional force of 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.

Adaption is limited to a maximum value of 80 N. The individual escalation stages depend on the operating request and history and are shown in the table below.

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.

Manual closing	1st Actuation (escalation stage 1)	2nd actuation (escalation stage 2)	3rd actuation (escalation stage 3)
Holding power window switches	Stop at 100 N (+15 N)	Stop at 130 N (+15 N)	Actuation remains active
Releasing power window switches	Reverse 20 mm (+5 mm)	Reverse 20 mm (+5 mm)	Actuation stopped
Automatic closing
Releasing power window switches	Stop at 60 N (-10 N); Reverse 125 mm (+5 mm)	Stop at 80 N (-10 N); Reverse 125 mm (+5 mm)	Only manual raising possible

If the power window switch is actuated again within 2 s after reversing is finished, the status changes. If the power window switch is actuated again after a time of 2 s, escalation stage 1 (1st actuation) is started again.

If pinching is detected during automatic window raising, triggered by the comfort closing function via the air recirculation function, the respective front door control unit, rear door control unit (model 222) or the rear control unit (model 217) starts with escalation stage 1 (1st actuation).

If pinching is detected during automatic window raising, triggered by the KEYLESS-GO function (with code 889 (KEYLESS-GO)) or by the side window closing function by PRE-SAFE®), the respective front door control unit, rear door control unit (model 222) or the rear control unit (model 217) starts with escalation stage 2 (2nd actuation).

If power windows are not normalized, the excessive force limiter is active starting at a pinching force of 100 N. The side window always reverses when it runs into the upper seal.

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 corresponding power window. The "rough road detection" required for this purpose is therefore activated starting at a speed of more than 8 km/h.

Additional function requirements for lock-up reversing 

• Power windows normalized

Lock-up reverse 

If the respective front door control unit, rear door control unit (model 222) or rear control unit (model 217) does not detect a change in position within 150 ms (+20 ms) or an increase in force of 160 N over the adjustment range traveled while the side window is being raised, this is evaluated as blocking. The raising is stopped immediately and the side window is opened 20 mm. The lock-up reversing function depends on the type of rolling up. Escalation stages for excess force limiter function apply.

Overheating protection 

The power window motors are protected by software thermal protection in the corresponding front door control unit, rear door control unit (model 222) or rear control unit (model 217). The software simulates temperature characteristics depending on the operating time. The parameters required for this were determined in tests and are stored in the corresponding front door control unit, rear door control unit (model 222) or rear control unit (model 217).

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

Actuation by PRE-SAFE® 

If the Electronic Stability Program control unit detects an unstable driving condition (e.g. understeering or oversteering), the side windows are closed to a defined position (50 mm before the upper stop) to minimize the risk of injury).

The Electronic Stability Program control unit transmits information on the PRE-SAFE® status and the request for PRE-SAFE® adjustment via the suspension FlexRay, the electronic ignition lock control unit and the interior CAN to the front door control units, the rear door control units (model 222) or the rear control unit (model 217).

The front door control units then actuate the front door power window motors directly. The rear door control units (model 222) or the rear control unit (model 217) directly actuate the rear door power window motors.

Crash ventilation 

Smoke particles are produced in the vehicle interior when the pyrotechnical restraint equipment is triggered. The front door side windows are opened automatically leaving a gap in order to allow these smoke particles to quickly disperse.

The supplemental restraint system control unit sends the crash signal over the user interface CAN, electronic ignition lock control unit and interior CAN to the front door control units. The front door control units then actuate the front door power window motors directly.

	Electrical function diagram for power windows	Model 222	PE72.29-P-2050-97SEA
		Model 217	PE72.29-P-2050-97SEB
	Overview of system components for windows and sightproofing		GF67.00-P-9999LF