GF82.30-P-2003FL Heating Wiper Support, Function

GF82.30-P-2003FL Heating Wiper Support, Function

Function requirements, general
^ Engine running (circuit 61 ON) n > 300 rpm
^ Outside temperature T < 5 °C

Heated wiper park position, general
Heating the wiper park positions at low outside temperatures prevents the wiper blades from freezing to the windshield.

Heated wiper park position function sequence
The front SAM control unit with fuse and relay module (N10/1) switches on the wiper park position heater (R2/10) via the wiper park position heater relay (N10/1kL) with the engine running and at an outside temperature of T < 5 °C.

This takes into consideration the engine temperature at which the wiper park position heater was switched on.
In dry weather conditions, the maximum operating time is t = 25 min.
If the outside temperature increases to a value of T > 15 °C, the front SAM control unit switches off the wiper park position heater.

The cutout temperature can be adjusted using the diagnostic tester.

The CDI control unit (N3/9) (with diesel engine) or ME-SFI [ME] control unit (N3/10) (with gasoline engine) makes the circuit 61 status available on the chassis CAN (CAN E).

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 actual outside temperature and transmits this to the instrument cluster (A1) via the interior CAN (CAN B). The instrument cluster calculates the outside temperature to be displayed taking the vehicle speed and the heat given off by the engine into consideration, and makes it available via the interior CAN.
The front SAM control unit reads in all the relevant data and actuates the wiper park position heater accordingly.

If the front SAM control unit cannot receive an outside temperature value from the instrument cluster, it calculates the outside temperature itself.

The wiper park position heater is switched off automatically under the following conditions:
- No wiper request for t > 25 min and engine coolant temperature of T < 70 °C
- Engine coolant temperature of T < 70 °C and the sun sensor (B32/3) signals "solar radiation through the windshield". The sun sensor information is not evaluated until after t = 15 min.
The data from the sun sensor are read in by the automatic air conditioning control and operating unit (N22/7) and made available on the interior CAN.
- No wiper request for t > 15 min and engine coolant temperature of T > 70 °C

If then a wiper request is received, the wiper park position heater is reactivated.
If the windshield has only been washed, the front SAM control unit then switches off the wiper park position heater after t = 10 min.

- When the vehicle is stationary, the wiper park position heater is switched off after t = 10 min.

The switch-off times can be adjusted using the diagnostic tester.

The wiper request is defined by means of the switch position of the combination switch (S4). The status of the combination switch is read in by the steering column tube module control unit (N80) and provided on the chassis CAN.

The engine coolant temperature is recorded by the coolant temperature sensor (B11/4). The CDI control unit or the ME-SFI [ME] control unit reads in the signal of the coolant temperature sensor directly, uses it to calculate the engine coolant temperature and then makes this value available over the chassis CAN.