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

GF88.79-P-2000GM Heat Left/right Outside Rearview Mirrors Function
- refinement package
- as of model year 09

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 left/right heated outside mirror function comprises the following partial functions:
^ Manually activating/deactivation heated outside mirror
^ Automatically activating/deactivation heated outside mirror

Additional function requirements for manually activating/ deactivating heated outside mirror
^ Circuit 15 On

The status of c. 15 is transmitted by the EIS control unit (N73) via the interior CAN.

Function sequence for manually activating/deactivating heated outside mirror
The rear window heater and the heated outside mirror are switched on with the rear window heater switch (N22s1) on the AAC control and operating unit (N22) (without code (581) Comfort automatic air conditioning) or the rear window heater switch (N22/7s1) on the Comfort AAC control and operating unit (N22/7) (with code (581) Comfort automatic air conditioning).

The control and operating unit transmits the switch-on request via the interior CAN to the rear SAM control unit (N10/8) which relays the request for the mirror heater to the left front door control unit (N69/1) and the right front door control unit (N69/2).
The left front door control unit switches on the mirror heater (M21/1r1). The right front door control unit switches on the mirror heater (M21/2r1).
When the rear window heater switch is actuated again, the function is terminated.

Detailed information is given in the separate function description "Rear window heater".

Additional function requirements for automatically activating/ deactivating heated outside mirror
^ Circuit 61 ON

The status of circuit 61 is transmitted by the CDI control unit (N3/9) (on diesel engine) or by the motor electronics control unit (N3/10) (on gasoline engine) to the engine compartment CAN. The central gateway control unit (N93) routes the signal on the interior CAN.

Function sequence for automatically activating/deactivating heated outside mirror
The heated outside mirror is operated depending on the dew point and the outside temperature.
The outside temperature is recorded by the outside temperature indicator temperature sensor (B14) and read directly by the control and operating unit. The control and operating unit transmits the outside temperature to the interior CAN.

The dew point is determined by the dew point sensor (B11/12) (with code (581) Comfort automatic air conditioning) and transmitted to the control and operating unit via the interior CAN.
On vehicles without code (581) Comfort automatic air conditioning a substitute value of
T = 13 °C is used for the dew point.

Switch-on requirements:
- Outside temperature ≤ Dew point temperature + 2 °C (programmable via STAR DIAGNOSIS)
- outside temperature < 15 °C

Cut-off conditions
- Outside temperature ≤ Dew point temperature + 5 °C (programmable via STAR DIAGNOSIS)
- Outside temperature > 18 °C=

The left front door control unit and right front door control unit receive the temperature values and switch the mirror heater on and off correspondingly.