Washer nozzle/washer nozzle hose heater, function

Function requirements, general

 "Engine running" or "drive train operational" signal on

 Outside temperature T < 5 °C

 The "Engine running" or "Drive train operational" signal is sent by the CDI control unit (N3/9) (diesel engine) or the ME-SFI [ME] control unit (N3/10) (gasoline engine) over the chassis CAN (CAN E) (up to 28.02.2013) or the chassis CAN 1 (CAN E1) (as of 01.03.2013) to the front SAM control unit with fuse and relay module (N10/1). 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 directly, calculates the actual outside temperature and sends this to the instrument cluster (A1) via interior CAN (CAN B). The instrument cluster calculates the outside temperature to be displayed, taking the vehicle speed and the heat dissipated from the engine into account, and sends this via interior CAN to the front SAM control unit.

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

Spray nozzle heater/spray nozzle hose heater, general

The spray nozzle heater and the spray nozzle hose heater prevent the washer fluid from freezing in the spray nozzles and the spray nozzle hoses.

Function sequence for spray nozzle heater/spray nozzle hose heater

The front SAM control unit switches on the spray nozzle heater (R2/1) and the spray nozzle hose heater (R2/11) (with CODE 875 (Heated windshield washer system)) with the engine running and an outside temperature of T < 5 °C.

If the outside temperature increases to T > 8 °C, the spray nozzle heater and the spray nozzle hose heater are switched off.