Windshield wiper

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Windshield wiper related parts in EPC.

Parts

Windshield Wiper Blade

Part No. Notes
A2208200045 LHD, single, To Date: 09/03/2000, Replaced by: A2208201845
A2208201845 LHD, pair, To Date: 09/03/2000 (~EUR 56)
A2208200645 LHD, single AERO, From Date: 09/03/2000, Replaced by A2208200845
A2208200845 LHD, single AERO, From Date: 09/03/2000, Replaced by A2208201145
A2208201145 LHD, single AERO, From Date: 09/03/2000, Replaced by A2208201345
A2208201345 LHD, single AERO, From Date: 09/03/2000, Replaced by A2208201545
A2208201545 LHD, pair AERO, From Date: 09/03/2000, Replaced by A2208201745
A2208201745 LHD, pair AERO, From Date: 09/03/2000 (~EUR 60)
A2208200145 RHD, single, To Date: 31/08/1999
A2208201445 RHD, pair AERO, From Date: 31/08/1999, Replaced by A2208201645
A2208201645 RHD, pair AERO, From Date: 31/08/1999 (~EUR 60)

Aftermarket replacement (for LHD vehicles):

  • OEM BOSCH Aerotwin A946S 3397118946 680mm (EUR 30)
  • VALEO 574317 700mm (EUR 35)
  • VALEO 577869 680mm (EUR 25)
  • SWF VisioFlex 119438 650mm (EUR 30)
  • SWF VisioFlex 119389 700mm (EUR 40)
  • CHAMPION KF68/C02 680mm (EUR 50)
  • DENSO DF123 700mm (EUR 30)
BOSCH Aerotwin A946S
SWF VisioFlex 119438.
CHAMPION KF68/C02.
SWF VisioFlex 119389.


Rubber only

It is possible, and much cheaper (~EUR 8 for a pair) to replace only the wiper blade rubber, but make sure that the new blades have the correct form.

Length: 685mm (27”) Width: 6mm

BOSCH Aerotwin refill (rubber).
Rubber replacement on a Bosch Aerotwin® wiper blade.
Rubber replacement on a Bosch Aerotwin® wiper blade.

SWISSINT sells high-quality Aerotwin wiper blade rubber refill with graphite coating (Art. Nr AT750). These are made of regular rubber but are simply coated with graphite, a coal-like, semi-metallic element used in pencil lead. When rubber is impregnated with powdered graphite, the blade is able to glide across the glass more smoothly and quietly due to reduced friction. Graphite also helps to protect the rubber from damage and deterioration. BOSCH Aerotwin original rubber is also graphite coated.

Windshield Wiper Park Position Guides

There are two marks on the front windscreen which identify the parked positions of the windscreen wiper blades.

The marks are a tiny window in the black undercoating, about a 1.5mm x 10mm clear slit in the black coating. They are very inconspicuous until you have seen them, then they are clearly visible.

One mark is on the right side and one in the centre of the windscreen. There is no mark on the left side. The two marks can be used to reinstall the wiper mechanisms if they have been removed.

Note it is obvious that the same windscreen is used for LHD and RHD vehicles, hence the marks are only really useful for LHD cars. For RHD cars the position of the right mark can be measured and transferred to the left side as a guide.

The marks are difficult to photograph due to the reflections in the windscreen. The next figure is a composite of two photos taken from the front of a RHD car.

Right Side Mark & Center Mark


Reset Automatic Windshield Wiper Function

  • Two people are required for this task as the doors have to be closed to reset this function.
  • First, pull and reseat your windshield wiper relays (locations are on the fuse diagram usually found in the tool compartment in your spare wheel well).
  • With engine running and all passenger doors closed, starting at 0 turn on wipers to #3 position, then put the switch in the 0 position then put it in the auto #1 (rain sensor position).
  • Then have your assistant splash water on the windshield.
  • The Automatic Windshield Wipers should now function normally.
W220 windshield wiper blade removal.

Wiper function

Slow wiping (stage 1) function sequence:

  • The slow windshield wiping function is switched on by turning the combination switch (S4) to position 2
  • The position of the combination switch (S4) is read in by the steering column module (N80) and sent to the interior compartment CAN as a message
  • The left front SAM control module (N10/6) receives this message and controls the wiper On and Off relay (K40/6kH)
  • Circuit 15R is switched via the wiper stage 1 and 2 relay (K40/6kG) to "circuit 53" (slow wiping) by the wiper motor (M6/1) . (The wiper stage 1 and 2 relay (K40/6kG) is then not actuated.)
  • The wiper motor operates at slow speed

Fast wiping (stage 2) function sequence:

  • The fast windshield wiping function is switched on by turning the combination switch (S4) to position 3
  • The position of the combination switch (S4) is read in by the steering column module (N80) and sent to the interior compartment CAN as a message
  • The left front SAM control module (N10/6) receives this message and actuates the wiper On and Off relay (K40/6kH) and the wiper stage 1 and 2 relay (K40/6kG)
  • Circuit 15R is switched via the wiper stage 1 and 2 relay (K40/6kG) to "circuit 53b" (fast wiping) by the wiper motor(M6/1). (The wiper stage 1 and 2 relay (K40/6kG) is then actuated.)
  • The wiper motor runs at high speed

Switching off wiping function:

  • If the combination switch (S4) has been turned to position 0, the above-mentioned message is no longer on the interior compartment CAN
  • If the wiper motor now reaches the park position, the left front SAM control module (N10/6) ensures that the wiper stops (If switch-off was accomplished from stage 2, the wiper motor is switched back to the slow stage until it reaches the park position)
  • The wiper motor stops in the park position

The wiper motor (M6/1) can be switched back to intermittent wiping by the automatic speed reduction.

As of 01/09/2002 the functions anti-lock protection, lock detection, stopping and final wiping are monitored independently by the reversing wiper system (UWA).

Windshield intermittent wiping function

Operational sequence:

  • The intermittent wiping function is switched on by turning the combination switch (S4) to position 1.
  • The position of the combination switch (S4) is read in by the steering column module (N80) and sent to the interior compartment CAN as a message
  • The left front SAM control module (N10/6) receives this message and initiates one wipe cycle (if the wiper was already moving, this wipe cycle is first brought to an end)
  • After one wipe cycle, the wiper motor (M6/1) is stopped
  • The intermittent pause is started.
  • At the end of the pause, the next wipe cycle is executed.


Control of wiper motor

The left front SAM control module (N10/6) controls the wiper motor (M6/1) by means of the wiper stage 1 and 2 relay (K40/6kG) and wiper On and Off relay (K40/6kH) so that the wiper wipes at speed stage 1.


Interruption of intermittent pause

If another wiper function is requested during an intermittent pause, this function is executed without taking the intermittent pause into consideration. After completion of this function, the intermittent pause is started again.


Control of the intermittent pause

The intermittent pause is dependent on the amount of moisture present on the windshield. The left front SAM control module (N10/6) analyses for this purpose the data from the rain/light sensor (B38/2). The exchange of data between the left front SAM control module (N10/6) and the rain/light sensor (B38/2) takes place via the interior compartment CAN and, because the rain/light sensor (B38/2) is not connected directly to the interior compartment CAN, via the overhead control panel control module (N70) as an interface.

In the event of a failure of the rain/light sensor (B38/2) the intermittent time is set to approx. 5 s.

As of 01/06/2000 there is a safety cutout when the front door is open.


System functions

Function prerequisites:

  • Circuit 15R ON


Windshield wipers

Switch position I = intermittent = pause duration dependent on quantity of moisture; can be regulated upward to continuous wiping stage 2. Switch position II = stage 1 = continuous wiping 40 cycles/min Switch position III = stage 2 = continuous wiping 60 cycles/min

A two-stage standard wiper control is used. This is actuated directly from the left SAM control module (N10/6).

Data are only transferred between the left SAM control module (N10/6) and the overhead control panel control module (N70) when there is a change to the data, or when one of the two control modules is initialized. The functions are interrupted with "Circuit 15R OFF".


Intermittent wipe (valid as of 01/09/2002)

Continuous wiper control by the rain/light sensor (B38/2). The top priority for switching on the wiper is always assigned to the combination switch (S4). Information such as the vehicle speed, the position of the wiper switch, the ambient light conditions as well as the outside temperature are received by the overhead control panel control module (N70) and processed in the algorithm implemented. The wiper system is actuated via the interior compartment CAN by means of the left SAM control module (N10/6).

The wiper is controlled depending on the particular quantity and frequency of moisture by:

  • Individual wipe cycles
  • Continuous wipe
  • Continuous wiping with the selection of the required wiper speed

The intermittent time is determined by the rain/light sensor (B38/2) (up to stage 2 continuous wiping). If communication with the overhead control panel control module (N70) fails at switch position I the intermittent wiping function is activated. If intermittent wiping is transmitted from position 0, the wipe cycle takes place immediately. After interrupting intermittent wiping by a wiper function, the intermittent pause elapses.

Intermittent times (emergency mode):

  • 1st intermittent time T/1 = 5 s 1 s
  • 2nd intermittent time T/2 = 1.5 s (T/1 with automatic speed reduction)

The rain/light sensor (B38/2) is activated by switching on the intermittent wiper setting and thus the CAN message generated by the left SAM control module (N10/6) via the overhead control panel control module (N70). The left SAM control module (N10/6) receives the request for intermittent wiping via the interior compartment CAN.


Switch positions (valid as of 01/09/2002)

With the combination switch (S4) position: intermittent (rain sensor position) the requests for the wiper take place via the overhead control panel control module (N70) from the rain/light sensor (B38/2).

If using the combination switch (S4) another wiper setting is selected, the request comes directly from the left SAM control module (N10/6) to the wiper.

The combination switch (S4) information as well as the requests from the overhead control panel control module (N70) are supplied by means of the interior compartment CAN.

Safety switch-off function (as of 01/06/2000)

Networking of safety cutout Intermittent wipe:

  • CANB - Interior CAN
  • A1 - Instrument cluster
  • B38/2 - Rain/light sensor (as of 01/09/2002)
  • K40/6 - Left front fuse and relay module
  • K40/6kG - Wiper stage 1 and 2 relay
  • K40/6kH - Wiper On and Off relay
  • M6/1 - Wiper motor
  • N10/6 - Left front SAM control module
  • N10/8 - Rear SAM control module
  • N70 - Overhead control panel control module
  • N80 - Steering column module
  • S4 - Combination switch
  • S17/3 - Left front door contact switch
  • S17/4 - Right front door contact switch


Safety cutout with the intermittent wiping function

The following safety precaution has been incorporated in order to minimize the risks of possible injuries:

  • The intermittent wiping function (combination switch in position 1) is suppressed at a vehicle speed of less than 5 km/h as

soon as one of the front doors is opened.

  • The function is possible again as soon as both front doors are closed

In order to permit the intermittent wiping function even in the event of a defective door contact switch (S17/3, S17/4), the states of the door contact switches have no effect at speeds above 3 km/h.


Fault analysis:

  • Failure of the serial communication interface to the left SAM control module (N10/6) - wiper motor

In the event of a failure of the serial communication interface or a fault report from the wiper motors (e.g.: Hall sensors defective), even when there is as yet no wiper request, an error message is sent from the left SAM control module (N10/6) via the interior compartment CAN to the instrument cluster (A1). The rain sensor and light information are sent from the overhead control panel control module (N70) only in the event of changes.


Wiper startup suppression

Suppression of the wiper function with the driver or passenger door open to prevent accidents.

The wiper function is suppressed when:

  • Combination switch (S4) is in position 1 (intermittent stage)
  • Driver or passenger door is open
  • v < 5 km/h and
  • Shift lever position is in P or N

If the driver or passenger door is open at v > 3 km/h, there is no wiper startup suppression.

Actuation of the wiper after a suppressed actuation takes place if:

  • the wiper switch has been pressed
  • an engaged drive position is detected, or a gear is engaged
  • v > 3 km/h

A wipe cycle which has already commenced, is not interrupted. The wiper moves as far as the park position.


Networking

For the safety cutout, the signals of the front door contact switch are needed. These are read in by the rear SAM control module (N10/8) and are sent via the interior compartment CAN to the left front SAM control module (N10/1).

The vehicle speed signal comes from the instrument cluster (A1) via the interior compartment CAN to the left front SAM control module (N10/1).


Fault report of the wiper

If, due to the internal thermal protection, the wiper signals the overload bit, this is signaled by the left SAM control module (N10/6) to the instrument cluster as a wiper fault.


Failure or lack of CAN communication to the overhead control panel

In the event of an incorrect message, the wiper request is rejected and only responded to again with the next correct message. In the event of five incorrect messages, the intermittent wipe control takes place as under 1 (T = 5 s +/- 1 s). If correct communication with the rain/light sensor (B38/2) can be established again, then the system switches back to rain/light sensor mode. No fault is displayed in the instrument cluster.


Timeout of the wiper startup suppression

  • For door contacts (rear SAM): doors closed (default value)
  • For combination switch (S4) request (electronic ignition switch/steering column module): last valid value
  • For v-signal: v > 3km/h

The function can be coded out.


Anti-lock protection, lock detection, stopping, final wiping

The functions are carried out independently by the UWA (reversal wiper system).


Special case for wiper startup suppression

A wipe cycle that has already been initiated (with request via combination switch (S4) "position 1" or "final wiping") is not interrupted by opening the driver or passenger doors. The wiper movement takes place until it reaches the park position. Further wiper requests (with combination switch (S4) "position 1") are, however, suppressed with the above-described criteria.

Wiper system automatic speed reduction function

The automatic speed reduction has an effect on the functions (valid as of 01/09/2002):

  • Wiping in stage "1"
  • Wiping in stage "2"

If the vehicle speed drops below 5 km/h, then the left front SAM control module (N10/6) switches the wiper motor (M6/1) from these functions back to intermittent wiping. The intermittent pause is controlled in this case by the rain/light sensor (B38/2).

Switching back to the selected wiper stage (valid until 31/08/2002)

If with increasing vehicle speed the value of 8 km/h is exceeded, the left front SAM control module (N10/6) switches the wiper motor (M6/1) automatically back again to the wiper stage ("1" or "2") set at the combination switch (S4).

The vehicle speed signal required for the speed reduction is received at the left front SAM control module (N10/6) via the interior compartment CAN from the instrument cluster (A1).

The speed reduction can be reset manually by pressing the combination switch (S4) again for each desired function.


Switching back to the selected wiper stage (valid as of 01/09/2002)

If a rain/light sensor (B38/2) is provided, the system always switches back to rain sensor mode. For this purpose, the rain/light sensor (B38/2) must be activated and "circuit 15 ON". If the rain/light sensor (B38/2) is present but defective, the standard way of switching back (switching back one stage) is carried out.

Instantaneous status: v-back-switching not in USA.

Anti-lock protection for wiper motor function

Lock-up recognition

Lockup of the wiper motor (M6/1) is detected by the left front SAM control module (N10/6) by the lack of signals from the cam switch.


Anti-lock protection for wiping in "stage 2" function

If this signal from the cam switch is missing for more than 4 s, then the left front SAM control module (N10/6) switches the wiper motor (M6/1) to "stage 1".

If the signal is still missing for a further 8 s, then the left front SAM control module (N10/6) switches the wiper motor (M6/1) off.


Anti-lock protection for the functions one-touch wiping, intermittent wiping, washing and wiping in "stage 1"

With these functions the left front SAM control module (N10/6) switches the wiper motor (M6/1) off, if the signals from the cam switch do not appear for more than 12 seconds.

In all cases, the anti-lock protection is canceled if: the corresponding function is requested again by pressing the combination switch (S4) or "circuit 15R" is switched on again.

If the wiper motor (M6/1) still locks after canceling the anti-lock protection, the wiper motor (M6/1) is switched off again as described above.

Slowing down wiper motor function

Following the completion of a wiping operation, the wipers must come to a stop in the park position.


Stopping wiper motor

To stop the motor, the wiper On and Off relay (K40/6kH ) is switched off by the left front SAM control module (N10/6). Through the opening of this relay:

  • The connection circuit 53 for the wiper motor (M6/1) is disconnected from the voltage supply circuit 15R
  • The connection circuit 53 for the wiper motor (M6/1) is connected to ground via an electronic switch (FET) of the SAM; this short-circuits the motor
  • This short circuit decelerates the motor (eddy current dynamometer)


Prerequisites for stopping wiper motor

The stopping of the wiper motor (M6/1) is only initiated if:

  • The wiper motor is switched off (combination switch (S4) in position 0) or
  • Intermittent wiping is switched on (combination switch (S4) in position 1) and an intermittent pause has just started
  • The cam switch is closed, and thus the park position has been reached

In order to detect the park position, the wiper motor (M6/1) has a cam switch. When the motor runs through the park position, the cam switch is actuated.

The signal from the cam switch is interrogated continuously by the left front SAM control module (N10/6) .

Wiper motor

  • M6/1 - Wiper motor

The wiper motor is located in the water trough underneath the windshield.

The purpose of the wiper motor is to drive the windshield wipers with two speed stages and detect exact end position of the wipers.

The drive for the windshield wipers consists of an electric motor with three brushes, gear and the cam switch on the output shaft.

Function

The wiper motor (M6/1) is a DC motor with three brushes. Depending on which pair of brushes is energized, the wiper motor (M6/1) operates at different speeds.


Cam switch

The cam switch is closed when the wiper motor (M6/1) is in the rest position. With each wiping cycle the cam switch opens and closes when the non-actuated state is reached. This generates the signal c. 31b.

Using the circuit 31b signal, it is possible to determine whether the wiper motor (M6/1)

  • is operating correctly,
  • locked up,
  • or in the rest position.

Wiper system

Networking of components:

  • CAN-B - CAN interior
  • B38 - Rain sensor (valid up to 08/31/2002)
  • B38/2 - Rain/light sensor (valid as of 9/1/02)
  • M6/1 - Wiper motor
  • N10/6 - Left front SAM control unit
  • N70 - Overhead control panel control unit
  • N80 - Steering column module
  • S4 - Combination switch

Preconditions for function:

  • Circuit 15R ON

The windshield wiper system is operated using the combination switch (S4). The following functions are possible:

  • Touch wiping: A single wipe is performed. (To do this, push the combination switch (S4) to the detent)
  • Intermittent wiper valid up to 31/08/2002: with automatic intermittent wipe control via the rain sensor (B38). To do this, turn the combination switch (S4) to position 1.
  • Intermittent wiper valid as of 02/09/2002: with automatic intermittent wipe control via the rain/light sensor (B38/2). To do this, turn the combination switch (S4) to position 1.


Switch positions At combination switch (S4) position: interval (rain sensor position) the wiper requests are sent by the rain sensor (B38) or as of 01/09/2002 by the rain/light sensor (B38/2) via the overhead control panel control unit (N70).

If another wiper position is selected using the combination switch (S4), the request is transmitted directly to the wiper by the left SAM control module (N10/6).

  • Intermittent wiping with slow speed (stage 1, approx. 40 cycles/min.) To do this, turn the combination switch (S4) to position 2.
  • Wiping at high speed (stage 2, approx. 60 cycles/min). To do this, turn the combination switch (S4) to position 3.
  • Washing: The windshield is wiped with additional water. To do this, push the combination switch (S4) beyond detent.

A data transfer between the left SAM control unit (N10/6) and the overhead control panel control unit (N70) only takes place if the data has changed or one of the two control units has been initialized. Operation is interrupted when "circuit 15R OFF".

The combination switch (S4) information and the requests from the overhead control panel control unit (N70) are provided by the interior CAN. A two-stage standard wiper control is used. It is actuated directly by the left SAM control unit (N10/6).

Wiper system, location of components (up to 31/05/2000)

  • B14 - Ambient temperature display temperature sensor
  • B38 - Rain sensor (up to 31/08/2002)
  • K40/6 - Left front fuse and relay module
  • K40/6kA - Wiper park position heater relay (for left hand drive vehicles only)
  • K40/6kG - Wiper stage 1 and 2 relay
  • K40/6kH - Wiper On and Off relay
  • M6/1 - Wiper motor
  • N10/6 - Left front SAM control module
  • N70 - Overhead control panel control module
  • N80 - Steering column module
  • R2/10 - Wiper park position heater (for left hand drive vehicles only)
  • S4 - Combination switch

Wiper system, location of components (as of 01/06/2000)

  • B14 - Ambient temperature display temperature sensor
  • B38 - Rain sensor (up to 31/08/2002)
  • B38/2 - Rain/light sensor (as of 01/09/2002)
  • K40/6 - Left front fuse and relay module
  • K40/6kA - Wiper park position heater relay (for left hand drive vehicles only)
  • K40/6kG - Wiper stage 1 and 2 relay
  • K40/6kH - Wiper On and Off relay
  • M6/1 - Wiper motor
  • N10/6 - Left front SAM control module
  • N10/8 - Rear SAM control module
  • N70 - Overhead control panel control module
  • N80 - Steering column module
  • R2/10 - Wiper park position heater (for left hand drive vehicles only)
  • S4 - Combination switch
  • S17/3 - Left front door contact switch
  • S17/4 - Right front door contact switch