Electrochrome Mirror

Exterior Rearview Mirror Functions

The following functions are possible with the exterior mirrors on the driver's and passenger doors:
- Horizontal and vertical mirror adjustment
- Mirror heating
- Mirror pivoting
- Automatic curb view
- Mirror memory
- Electrochrome

The controls for the exterior mirror functions are accommodated in the driver's and passenger door modules and in the driver's seat module. The exterior mirror functions are operated by means of the buttons in the switch block in the driver's door and the memory buttons in the center console. The information from the switch block to the door modules is routed via a single-line communications data bus. The control modules communicate with each other via the K-CAN PERIPHERALS data bus.

Brief description of components

DM door module
The door modules register the signals of the switches and sensors installed in the doors and control the drives installed in the doors. Information is received and sent via the K-CAN PERIPHERALS data bus.

Seat module, driver's seat
Among others the memory switches and the associated evaluation of the mirror memory function are integrated in the driver's seat module. The seat module evaluates the key number and memory button information and transmits information on assuming or memorizing the memory position to the front door modules.

Switch block, driver's door
The switch block in the driver's door incorporates the buttons for exterior mirror adjustment, power window operation, the rear roller blind and the child lock.
- The direction button (arrows) is used to move the glass in the exterior mirror base in the horizontal and vertical directions.
- Another button is used to initiate pivoting of the exterior mirror.
- The slide switch is used to switch between operating the mirror on the driver's and passenger doors.

Switch block, center console
The switch block with the buttons for the mirror memory function is accommodated in the center console.

Exterior rearview mirror
An exterior rearview mirror consists of a mirror base attached to the car door and a mirror head mounted to the base. The electric drive for pivoting the mirror head is installed in the base. The mirror head incorporates electric drives for adjusting the mirror glass in the horizontal and vertical directions and a heater for deicing the glass.

Drive (electric motor with gear unit)
The drives for adjusting the mirror glass in the horizontal and vertical directions and for the mirror pivoting function consist of an electric motor with gear unit. Adjustment of the mirror glass and pivoting of the mirror are achieved by reversing the direction of rotation of the electric motor. For the purpose of position recognition, a potentiometer is integrated in the drives for adjusting the mirror glass in the horizontal and vertical directions.

Main functions

Mirror adjustment
The glass in the head of the exterior mirror is adjusted when
- the door module is activated and
- the direction button (arrows) is pressed in one position.

Horizontal and vertical adjustment can only be performed in succession (consecutively). Diagonal adjustment is not possible.

The mirror cannot be adjusted when it is pivoted.

Mirror heating
The mirror heater serves to deice the mirror glass. The heat output and the ON period are automatically controlled and are dependent on the outside temperature and the wiper intensity. When the wiper is activated, the heat output is increased by a prespecified factor so as to ensure safe deicing of the mirror glass. These data are made available to the driver's door module via the K-CAN peripherals data bus.

The mirror heater is deactivated with terminal 50 ON (load deactivation) and in the event of undervoltage. It is reactivated automatically when the restarting voltage is reached.

Mirror heating with activated independent heating: With this special equipment, the mirrors are also heated with terminal 15 OFF after the independent heating has been switched on for 5 minutes (encodable). The information is made available by the independent heating control module via the K-CAN PERIPHERALS data bus.

Mirror pivoting
With this special function, the heads of the exterior mirrors can be pivoted towards the door window to reduce the width of the car and swiveled upwards.

Mirror pivoting is possible when
- the door module is activated and
- the button in the driver's door switch block is operated.

The pivoting function is disabled at speeds in excess of 20 km/h (encodable). A function that has just been initiated is not affected however.

The function is always in effect at lower speeds.

Pivoted-in mirror heads are always pivoted out when the button is operated.

The direction of movement is reversed when the button is operated while an operation is running.

Automatic engagement of mirror head: If a mirror head has been separated from the drive by external force application, both mirror heads are moved in the "pivot in" direction the next time the button is pressed. The drive of the disengaged mirror head is activated by the blocking current detection facility until the head is reengaged in the mirror base. The button must be pressed a maximum of twice in order to establish mechanical engagement and synchronization. Both mirrors are pivoted out again the next time the button is pressed.

Automatic curb view
This function is only available with the special mirror memory equipment. The mirror glass can be vertically adjusted (pivoted down) in order to afford a better view of the curb. The pivot down angle (mirror position) can be encoded.

This function can only be executed when
- the slide switch for selecting exterior mirror operation is set to the driver's door and
- there is no trailer hooked up to the car.

Vertical adjustment (pivoting down) takes place automatically
- one second after the reverse gear has been engaged and
- with terminal 15 ON.

The function is deactivated and the exterior mirror returns to its original position when
- the slide switch for operating the exterior mirror is set to the passenger side,
- the reverse gear is disengaged or
- with terminal 15 OFF.

Manual operation is disabled during the functional sequence. The function takes effect regardless of whether the passenger door is open or closed.

Mirror memory
This function is a special feature for expanding the seat memory function. The current settings of the exterior mirrors on the driver's and passenger doors can be memorized with the memory buttons in the center console and with the key memory function. Positions that have already been memorized can be selected.

12 memory locations are available in each of the front door modules for memorizing the positions of the mirror glass. Four keys that can be personalized are possible for each car. Each key is thus assigned three memory positions:
- Two memory locations for both memory buttons in the center console and
- one memory location for the key memory.

When the car is locked by the key, the current mirror position is stored in the memory location of the presently active key. In this way, when the car is unlocked, the last position (referred to the key used) is always set.

- A setting activated by the key memory is cancelled when the memory button is operated and the position of the memory button is set.
- Manual adjustment by means of the buttons in the driver's door switch block interrupts all memory adjustments.
- The function is not dependent on the terminal status.

Electrochrome
With this special function, the exterior mirrors are automatically dimmed when a light source that dazzles the driver is detected coming from the rear. The dimming is dependent on the degree of dazzling. The sensor is performed by means of the sensors inside the car and the control system integrated in the interior rearview mirror. The activation signals are looped from the interior mirror through the front door modules to the exterior mirrors.

Blocking position detection
To protect the drives against overloading, each door module contains a function for detecting the blocking current.

The current for the electric motor increases as soon as the drive reaches a blocking position. The control module compares the current when the drive is blocked with the starting current of the electric motor in normal operating mode. The control module detects from the difference in the currents that a blocking position has been reached and shuts down activation of the electric motor.

Safety function

Overload protection/anti-repeat circuit
- Mirror adjustment: To protect the drive against overheating, the activation time for any mirror adjustment is restricted to max. 10 seconds. The drives are disabled for 10 seconds once the activation time has elapsed.
- Mirror pivoting: To protect the drive against overheating, the pivoting function is disabled after a total running time of 45 seconds.

Undervoltage cutout
The supply voltage is monitored in the door modules. All the mirror functions are disabled at a voltage of < 8.5 V. If the voltage drops below this threshold once, the functions are available again from 9 V.

Country-specific version