Automatic dimming outside mirror and inside rearview mirror, function - GF88.79-P-2010LE

MODEL 216.3 as of model year 09 /YoM 08 

MODEL 221.0 /1 with CODE (249) Automatically dimming inside rearview mirror and outside mirror (driver) as of model year 09 /YoM 08 

Function requirements 

• Reverse gear not engaged
• Interior illumination not switched on

The reverse gear status is transmitted by the central gateway control unit (N93) to the interior CAN.

Automatically dimming outside mirror and inside rearview mirror, function sequence 

The mirror glass of the inside rearview mirror (A67) and left electrically adjustable and heated outside mirror (M21/1) is electro-chromatically dimmable. 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 unit senses the ambient light via the mirror dimming sensor, forward (A67h1) and the light hitting the mirror glass via the mirror dimming sensor, rearward (A67h2).

The inside rearview mirror evaluates these input variables and supplies dimming information to the overhead control panel control unit (N70), which transmits the message for mirror dimming to the passenger compartment CAN-B bus.

The left front door control unit (N69/1) (model 221) or left door control unit (N69/1) (model 216) relays the dimming information and transmits the corresponding actuation voltage to the mirror dimming circuit (M21/1h1) in the left electrically adjustable and heated outside mirror.

The inside mirror dimming information is sent to the overhead control panel control unit, which supplies the voltage to the inside rearview mirror dimming circuit.

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

	Electrical function schematic for automatic dimming mirror	Model 216	see PE88.79-P-2056-97CAA
		Model 221	PE88.79-P-2056-97SAA
	Left door control unit, component description	N69/1 Model 216	see GF72.29-P-4124LA
	Left front door control unit, component description	N69/1 Model 221	see GF72.29-P-4141LE
	Overhead control panel control unit, component description	N70	see GF82.20-P-5216LE
	Component description for the EZS control unit	N73	see GF80.57-P-6003LE
	Central gateway control unit, component description	N93	see GF54.21-P-4170LE
	Inside rearview mirror unit, component description	A67	see GF68.49-P-2105LE