GF88.79-P-2010CE Automatic Dimming Outside Mirror and Inside Rearview Mirror, Function

GF88.79-P-2010CE Automatic Dimming Outside Mirror And Inside Rearview Mirror, Function
- with CODE (249) Automatically dimming inside rearview mirror and outside mirror (driver)
- as of model year 09


Function sequence for automatically dimming outside and inside rearview mirror
^ C. 15R On
^ Reverse gear not engaged
^ Interior illumination not switched on

The status of circuit 15 is transmitted by the electronic ignition lock control unit (N73) over the interior CAN (CAN B).

Automatically dimming outside mirror and inside rearview mirror, function sequence
The mirror glass on the inside rearview mirror (A67) and left outside mirror (M21/1) dims electrochromatically. This is realized by a layer of electrolyte gel in the mirror which controls the light permeability in increments depending on the voltage applied.

The inside rearview mirror senses the ambient light via the mirror dimming light sensor, forward (A67h1) and the light hitting the mirror glass via the mirror dimming light sensor, rearward (A67h2). The inside rearview mirror evaluates these input variables and supplies dimming information via the wiper/inside rearview mirror LIN (LIN 2) to the front SAM control unit with fuse and relay module (N10/1), which sends the message for mirror dimming via the interior CAN.
The left door control unit (N69/1) receives the dimming information and supplies the corresponding actuation voltage to the mirror dimming (M21/1h1) of the left outside mirror. The inside rearview mirror is dimmed by actuation of the mirror dimming (A67h3).

If an interior lamp is switched on during mirror dimming or the reverse gear is engaged, the dimming is interrupted.

Reading status of reverse gear:
On model 204.0/2 with transmission 711 or 716:
The backup lamp switch (S16/2) is read in directly by the front SAM control unit. This sends the status directly to the inside rearview mirror and via the interior CAN to the left front door control unit which actuates the left outside mirror.

For transmission 722:
The request "Shift to gear range R" is defined by the corresponding selector lever position and the electronic selector lever module control unit (N15/5) relays this status via the drive train CAN (CAN C) to the CDI control unit (N3/9) (for diesel engines) or ME control unit (N3/10) (for gasoline engines). This relays the signal via the chassis CAN to the front SAM control unit which sends the status directly to the inside rearview mirror and via the interior CAN to the left front door control module which actuates the left outside mirror.