GF88.79-P-2000FL Heat Left/Right Outside Rearview Mirrors Function

GF88.79-P-2000FL Heat Left/right Outside Rearview Mirrors Function

Function requirements, general
^ No overvoltage or undervoltage
^ On-board electrical system consumer shutoff not active
^ Particular (local) front power window not active

Heat left/right outside mirror, general
The heated outside mirror is activated depending on the temperature or the combination with the heated rear window (R1).

The left/right heated outside mirror function comprises the following partial functions:
^ Function sequence for temperature-dependent control
^ Function sequence for control when rear window heater is activated

Function sequence for temperature-dependent control
^ Circuit 61 ON

The circuit status c. 61 is provided by the CDI control unit (N3/9) (on diesel engine) or ME-SFI control unit (N3/10) (on gasoline engine) via chassis CAN (CAN E) to the front SAM control unit with fuse and relay module (N10/1), which routes the information to the interior CAN (CAN B).

Function sequence for temperature-dependent control
The mirror heater is operated depending on the following values:
- Ambient temperature
- Dewpoint temperature

Outside temperature:
The outside temperature is detected by the outside temperature sensor (B14). The front SAM control unit reads in the data of the outside temperature sensor, calculates the outside temperature and transmits the data to the instrument cluster (A1) via the interior CAN (CAN B). The instrument cluster calculates the temperature to be displayed considering the vehicle speed as well as the heat radiated from the engine and provides the corrected outside temperature value to the left front door control unit (N69/1) and right front door control unit (N69/2) via the interior CAN.

Dew point temperature:
Vehicles with code (581) Comfort automatic air conditioning: The dew point temperature is sensed by the dew point sensor (B11/12) and is transmitted via the air conditioning LIN (LIN B8) to the automatic air conditioning control and operating unit (N22/7). The automatic air conditioning control and operating unit sends the information to the left front door control unit and right front door control unit via the interior CAN.

If the value of the dew point is implausible or the dew point is value is not available, a substitute value of T = 13 °is used. Vehicles without code (581) Comfort automatic air conditioning: Since a dew point sensor is not installed on this variant, the substitute value of T =13 ° is used.

Mirror heater switched on
- Outside temperature ≤ dew point + 2 °C (programmable via diagnosis tester)
- outside temperature < 15 °C

Mirror heater switched off:
- Outside temperature ≥ dew point + 5 °C (programmable via diagnosis tester)
- Outside temperature > 18 °C=

If the outside temperature value received is not plausible, the mirror heater is always switched on.

Function requirements for control when rear window heater is activated
^ c. 15R On

The electronic ignition lock control unit (N73) transmits the circuit status c. 15 via the interior CAN (CAN B).

Function sequence for control when rear window heater is activated
When the rear window heater button (N22/7s1) is actuated, the request rear window heater is transmitted by the automatic air conditioning control and operating unit to the rear SAM Control unit with fuse and relay module (N10/2) via the interior CAN. The rear SAM control unit transmits the status rear window heater to the left front door control unit and right front door control unit via the interior CAN. The mirror heater (M21/1r1) in the left outside mirror (M21/1) and the mirror heater (M21/2r1) in the right outside mirror (M21/2) is activated when the rear window heater is switched on.

The mirror heater is switched off, when the heated rear window is switched off.