Brief description of components

The following components supply input signals required for operation of the wash/wipe system:

• Wiper switch 

  The wiper switch is operated by a brief press (as for the E65). The wiper switch does not lock into place.

  The signal from the wiper switch is passed on by the steering-column switch cluster (SZL) to the Safety and gateway module (SGM). The SGM transmits the signal to the body basic module (KBM).

  The axial switch on the end of the wiper switch is used to activate automatic mode (automatic control of wipers by rain/light sensor). When automatic mode is not active, intermittent wiper mode is controlled according to vehicle speed.

• Rain/light sensor 

  The rain/light sensor is integrated in the rear-view mirror pedestal attached to the windscreen. The rain/light sensor is a combined rain sensor and ambient-light sensor. It detects the amount of rain falling on the windscreen in order to control the windscreen wipers, and the level of ambient light in order to control the headlights.

  The rain sensor sends the "Switch on wipers" request to the body basic module (KBM) via the body CAN bus (K-CAN).

The following control units are involved in wash/wipe system functions:

• Body, basic module 

  The body basic module (KBM) controls the wash/wipe system (on the Touring this also includes the wash/wipe system for the rear window).

  The body basic module is connected via the K-CAN, for instance, with the:

  • Safety and gateway module (SGM)
  • Rain-light sensor (RLS)
  • Integrated automatic heating and air-conditioning system (IHKA)
• Steering column switch cluster 

  The steering-column switch cluster (SZL) forms the interface between the wiper switch and the Safety and gateway module (SGM). The signals are transmitted via the byteflight data bus.

• Safety and gateway module 

  The Safety and gateway module (SGM) forms the gateway between K-CAN and byteflight.

• Integrated automatic heating and air-conditioning system 

  The integrated automatic heating and air-conditioning module (IHKA) controls the washer-jet heating system.

The following actuators are operated in order to perform wash/wipe system functions:

• Wiper motor 

  The wiper system is a twin-arm synchronous system with reciprocating action (four-bar linkage).

  The wiper motor is a rotary motor without an electronic module.

  The wiper motor is controlled by the body basic module (KBM) via a double relay.

  The wiper motor's end position (off position) is detected by a reset contact integrated in the wiper motor.

  The crank is permanently connected to the wiper motor.

  Touring (E61):

  The rear window wiper motor is mounted on the rear window.

  The rear window wiper motor is controlled by the body basic module (KBM) via a relay.

  The rear window wiper motor's end position (off position) is detected by a reset contact integrated in the wiper motor.

• Windscreen and rear window washer pump (on the Touring) 

  Both washer pumps are attached to the washer fluid reservoir. The washer pumps are controlled by the body basic module (KBM). The washer jets are not adjustable. The new-design washer jets (fluidic jets) produce a pulsating, fan-shaped jet of fluid.

• Headlamp-washer pump 

  The headlamp washer system is an optional extra (option 502).

  For the option 502 the washer fluid reservoir holds 5 liters instead of 3 liters (basic version; the Touring reservoir always holds 5 liters).

  The headlamp-washer pump is mounted on the washer-fluid reservoir. The washer pump is controlled by the body basic module (KBM) via a relay.

• Heated washer jets 

  The washer-jet heater system prevents the washer jets freezing in cold weather.

  The washer-jet heater system is controlled by the IHKA module on the basis of outside temperature (< 3°C).

  The washer-jet heating system consists of heating resistors.