Wiper Blade Heater, Function - GF82.30-P-2004FH

Model 238 

Up To Model Year 2021 

With Code 874 (MAGIC VISION CONTROL, heated) 

Function requirements, general 

• "Engine running" or "Drivetrain operational" signal set for t > 3 s:

  The CDI control unit (N3/9) (with diesel engine) or the ME-SFI [ME] control unit (N3/10) (with gasoline engine) sends the signal "Engine running" or "Drivetrain operational" via drive train CAN 1 (CAN C1), powertrain control unit (N127), chassis FlexRay (Flex E), electronic ignition lock control unit (N73) and interior CAN (CAN B) to the front SAM control unit (N10/6).

• Outside temperature T < 5 °C:

  The outside temperature is detected by the outside temperature sensor (B14). The SAM control unit reads in the signals of the outside temperature sensor and uses them to calculate the outside temperature.

Wiper blade heater, general 

The wiper blade heater, consisting of the left wiper blade heater (R2/12) and the right wiper blade heater (R2/13), prevents the washer fluid nozzles in the wiper blade from freezing.

Apart from this, the flexibility of the wiper blades is also retained and the wiper blades are prevented from freezing to the windshield.

Function sequence for wiper blade heater 

If the outside temperature drops below T < 5 °C, the front SAM control unit switches on the wiper blade heater via the windshield washer system junction box (R2/6) as follows:

• Between T = +5 °C and -2 °C: The wiper blade heater is activated for t = 20 s, the break time between the activation cycles is t = 40 s.
• Between T = -2 °C and -9 °C: The wiper blade heater is activated for t = 30 s, the break time between the activation cycles is t = 30 s.
• Between T = -9 °C and -15 °C: The wiper blade heater is activated for t = 40 s, the break time between the activation cycles is t = 20 s.
• From T = -15 °C: The wiper blade heater is permanently activated.

If the temperature changes, the preceding cycle is always run through to the end; for permanent actuation, a cycle time of t = 60 s is assumed.

When the windshield washer system pump (M5/1) is actuated, the wiper blade heater is interrupted.

When the windshield washer system pump is no longer actuated, the wiper blade heater is actuated again after t = 5 s.

The energy management can switch off the wiper blade heater. Detailed information is available in a separate document.

	Electrical function schematic for wiper blade heater		PE82.30-P-2060-97DCA
	Overview of system components for windshield wiper system		GF82.30-P-9996FH